Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Short-range foraging of the honey bee, Apis mellifera ligustica spin Cmiralova, Daniela 1977

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1977_A6_7 C58.pdf [ 4.93MB ]
Metadata
JSON: 831-1.0093972.json
JSON-LD: 831-1.0093972-ld.json
RDF/XML (Pretty): 831-1.0093972-rdf.xml
RDF/JSON: 831-1.0093972-rdf.json
Turtle: 831-1.0093972-turtle.txt
N-Triples: 831-1.0093972-rdf-ntriples.txt
Original Record: 831-1.0093972-source.json
Full Text
831-1.0093972-fulltext.txt
Citation
831-1.0093972.ris

Full Text

SHORT-RANGE FORAGING OF THE HONEY B E E , APIS M E L L I F E R A LIGUSTICA SPIN. by DANIELA CMIRALOVA B.Sc. , University of British Col umbi a, 1975 A THESIS SUBMITTED IN P A R T I A L F U L F I L M E N T OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE F A C U L T Y OF GRADUATE STUDIES THE DEPARTMENT OF P L A N T SCIENCE We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA August, 1977 Daniela Cmiralova In presenting th is thes is in p a r t i a l fu l f i lment of the requirements for an advanced degree at the Univers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make it f ree ly ava i lab le for reference and study. I fur ther agree that permission for extensive copying of th is thes is for scho la r ly purposes may be granted by the Head of my Department or by h is representat ives . It is understood that copying or publ ication of th is thes is for f inanc ia l gain sha l l not be allowed without my wri t ten permission. Department of P l a n t Science The Univers i ty of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date AggustlZth. 1977 i i A B S T R A C T Short-distance scouting and r e c r u i t i n g behaviour of the Italian honey-bee, A p i s m e l l i f e r a l i g u s t i c a Spin., and the a c c u r a c y with which a r e c r u i t locates a food source indicated by s u c c e s s f u l f o r a g e r s were investigated in this study. Peppermint, orange, and cinnamon o i l scents were m o r e attractive than the scents of pure honey, lavender, or anise seed o i l . Sugar stimulated f u r t h e r v i s i t s , but when a nearby source d r i e d up, v i s i t o r s q u i c k l y went to a m o r e distant source, though they in t e r m i t t e n t l y checked the o r i g i n a l s i t e . The concentration of the sugar solution d i r e c t l y influenced recruitment. C o l o u r and shape were most important f o r r e c r u i t s i n i t i a l l y l o cating an attractive site, but a r e c r u i t would not land and take up food unless the c o r r e c t scent was present. Bees r e g u l a r l y investigated and v i s i t e d dishes in sunlight, but seldom v i s i t e d dishes in shadow. Scouts communicated d i r e c t i o n f o r distances as short as 2. 5 me t e r s . When the l o c a t i o n of the food s o u r c e was changed, bees s e a r c h e d un t i l they found the new location. T h e y then continued to a r r i v e v i a the o r i g i n a l l ocation f o r a p p r o x i m a t e l y one half-hour; thereafter they t r a v e l l e d d i r e c t l y between the hive and new location, taking d i r e c t i o n a l bearings to those r e s p e c t i v e p l a c e s . In absence of p o l a r i z e d sky-light, the route to a low source went around landmarked obstacles; in p r e sence of p o l a r i z e d light, the bees flew o v e r such obstacles;. When leavi n g a new food location after t h e i r f i r s t two or three v i s i t s , bees hovered over it, c i r c l e d , and s p i r a l l e d upward in a se;t pattern; during l a t e r v i s i t s they returned d i r e c t l y to hive without such l o c a t i o n a l checks When two food s o u r c e s were set up at the same distance and d i r e c t i o n f r o m the hive, but at different heights, two d i s t i n c t groups of f o r a g e r s formed, each r e c r u i t e d to only one of the food sources by the o r i g i n a l scouts. These re s u l t s show that r e c r u i t s of the Italian honey bee, Apis m. l i g u s t i c a , can locate a food source r e p o r t e d by others f o r a g e r s with great a c c u r a c y even at short distances f r o m the hive. iv T A B L E O F C O N T E N T S Page A B S T R A C T i i L I S T O F T A B L E S v L I S T O F F I G U R E S v i L I S T O F P L A T E S viuiu A C K N O W L E D G E M E N T S ' ix I N T R O D U C T I O N 1 L I T E R A T U R E R E V I E W 4 M A T E R I A L S AND M E T H O D S 15 R E S U L T S 22 1. V i s u a l a t t r a c t i v e n e s s of food source 22 2. O l f a c t o r y attractiveness of food source ' 26 3. E f f e c t of sugar concentration on r e c r u i t m e n t 30 4. V i s u a l vs. o l f a c t o r y attractiveness of fodd source 34 5. Use of landmarks and p o l a r i z e d light by f o r a g e r s 41 6. E f f e c t of location of food source on foraging: 44 sunlit vs shadowed ar e a s 7. F o o d r e l o c a t i o n and s e a r c h i n g behaviour 49 8. Height indication 53 DISCUSSION 59 SUMM^RcYiC ' r 74 L I T E R A T U R E C I T E D 77 V L I S T O F T A B L E S T a b l e Page I A t t r a c t i v e n e s s of v a r i o u s c o l o u r s and shapes at food 23 source. II A t t r a c t i v e n e s s of var i o u s scents at food source. 27 III E f f e c t of sugar concentration in the feeding solution 31 on recruitment. IV V i s u a l vs oIfactory attractiveness of food source in a short 36 per i o d . (a) Two inconspicuous s o u r c e s 30 c m right and lef t of c e n t r a l conspicuous source. (b) One conspicuous and one inconspicuous source 37 having two sugar concentrations and located f a r t h e r f r o m each other (5 m) than f r o m the hive (3 m). V F o r a g i n g and r e c r u i t i n g a c t i v i t i e s 46 (a) under c l e a r conditions when two i d e n t i c a l food s o u r c e s are set i n two di s t i n c t locations: (i)) in a sunlit a r e a (ILight) and (ii) in shadow (Dark); (ib) under cloudy conditions when there is no di s t i n c t i o n 46 in the i l l u m i n a t i o n of two locations, of two i d e n t i c a l food sources. r-VI S e a r c h i n g behaviour following r e l o c a t i o n of food source. 50 VII R e c r u i t m e n t and f o r a g e r mix-up at two id e n t i c a l food 54 sources located at the same distance and d i r e c t i o n f r o m the hive but at two different heights (0 a n d £ 170 cm). VIII R e c r u i t m e n t and f o r a g e r mix-up at two i d e n t i c a l food 55 sources located at the same distance and d i r e c t i o n f r o m the hive but at two different heights (0 and 170 cm) when distance is gradually i n c r e a s e d . v i LIST OF FIGURES Figure . Page la Scout's discovery time and recruitment at seven 25 visually different food sources during a 60-minute pe riod. lbb Number of bees visiting seven visually different food 25 sources 30 and 60 minutes after exposure. 2 Scout's discovery time and recruitment at six olfactorily 29 different food sources. 3 Effect of sugar concentration in the feeding solution on 33 recruitment over a 30-minute period. 4a Scout's discovery time and recruitment to one visually 39 attractive and two olfactorily attractive food sources in a 15-minute period. 4b Scout's discovery time and recruitment to one visually 39 attractive and one olfactorily attractive food source in a 15-minute period. 5 Map of experimental area, showing forager flight paths 43 to a relocated food source (behind flower bed). 6a Scout's discovery time and recruitment under clear 48 conditions when two identical food sources are set in two distinct locations: (i) inaa sunlit area (Light) and (ii) in shadow (Dark). 6b Scout's discovery time and recruitment under cloudy 48 conditions when there is no distinction between the illumination of two locations of the two identical food sources. 7a Number of scouts and recruits at the initial location 52 of the food during a 30-minute interval. 7b Number of scouts arriving at relocated food source 52 via the initial location, or directly from hive during a 30-minute interval after relocation. Number of r e c r u i t s a r r i v i n g at relocated food source v i a the i n i t i a l location or d i r e c t l y f r o m hive d u r i n g a 30-minute i n t e r v a l after r e l o c a t i o n . R e c r u i t m e n t and f o r a g e r mix-up at two ddentical food sources located at the same distance and d i r e c t i o n f r o m the hive but at two dif f e r e n t heights (0 and 1. 7 m) when distance is gradually i n c r e a s e d . V 1 U L I S T O F P L A T E S P l a t e Page I E x p e r i m e n t a l hive. 17 II T r a i n i n g honey bees to forage at experimental 17 food sources. III One m a r k e d f o r a g e r and one unmarked r e c r u i t 20 at the feeding dish. IV M a r k e d f o r a g e r s crowding at the feeding dish. 20 V M a r k e d f o r a g e r looking f o r food at v i s u a l l y 35 unattractive location. VI Boundary between the sunlit (left) and shaded (right) 45 areas in the experimental garden. ix A C K N O W L E D G E M E N T S I w i s h to thank the m e m b e r s of my committee, Dr. R.H. E l l i o t t , Dr. V. C. Runeckles, and Dr. W. G. Wellington f o r th e i r i n t e r e s t and suggestions throughout the p e r i o d of this study. In p a r t i c u l a r , I would like to thank my r e s e a r c h s u p e r v i s o r , Dr. W. G. Wellington, f o r his time and effort as we l l as f o r financial^ and m o r a l support during the project. His encouragement and c r i t i c i s m throughout the p r o g r a m m e have greatly contributed to my education and apprec i a t i o n of insec t behaviour. I am also v e r y grateful to M r . D. G. P e a r c e and M r . A. Neighbour fromtthe Department of P l a n t Science f o r th e i r generous help in m a t t e r s rela t e d to apiculture and hive-building; to two l o c a l beekeepers, M r . E. D y c k and Mr. E . J. H i r m e r , who qu i c k l y supplied queen, bees and advice in times of great need; and to Sel-Win C h e m i c a l C o l . f o r co m p l i m e n t a r y samples of scented o i l s . M y s p e c i a l thanks go to Dr. Wellington's f a m i l y , who v e r y g r a c i o u s l y endured mine as w e l l as the bees' presence in the i r garden throughout the summer of 1976. 1 I N T R O D U C T I O N T h e r e has been an enormous amount of r e s e a r c h done on the f o r a g i n g behaviour of the honey bee. Since 1923, when von F r i s c h said that bees did not indicate the d i r e c t i o n of a nearby food source, v e r y l i t t l e work has been c a r r i e d out on short-range foraging, and m o s t of that has been m a i n l y concerned with dance a n a l y s i s . A c c o r d i n g to von F r i s c h (1923), when a food source is l e s s than 100 m e t e r s away f r o m the hive, a s u c c e s s f u l f o r a g e r i n f o r m s the w o r k e r s in her hive by p e r f o r m i n g a round dance on the comb after her return. The r e c r u i t s locate the a d v e r t i s e d food source by s e a r c h i n g f o r the flower scent picked up f r o m the body of the dancer in e v e r y d i r e c t i o n f r o m the hive and at i n c r e a s i n g distances until they a r r i v e at the feeding place. In 1946, von F r i s c h (Engl, t r a n s l a t i o n 1947) was able to show that when the distance between the hive and food source is 100 m e t e r s o r more, the dancer p e r f o r m s a waggle dance, i m p a r t i n g to her f o l l o w e r s v e r y p r e c i s e information about the distance and d i r e c t i o n of that food source with r e s p e c t to t h e i r hive. Since these two m a j o r rep o r t s , v a r i o u s aspects of honey bee f o r a g i n g have been studied by von F r i s c h and his school as w e l l as other w o r k e r s , r a l l c o n c e r n i n g themselves c h i e f l y with long-range foraging. Von F r i s c h used almost e x c l u s i v e l y the A u s t r i a n bee, Apis m e l l i f e r a c a r n i c a f o r his experiments, while some of his students l a t e r expanded the observations to five other races of Apis m e l l i f e r a . 2 Although B i s e t z k y (1957) and Boch (1957), among others, have shown that the distance at which the information-loaded waggle dance det e r i o r a t e s to f o r m the non-specific round dance v a r i e s c o n s i d e r a b l y with the race of bees used in the experiments, the m a i n body of l i t e r a t u r e s/till repeats the o r i g i n a l statements of von F r i s c h . T h e r e is li t t l e doubt that von F r i s c h influenced the choice of the f i e l d of study of m o s t subsequent in v e s t i g a t o r s . T h i s acceptance by others has p e r s i s t e d to this day. The la t e s t examples of such 'blind faith' can be found in Wilson's The Insect Societies (1971); Lindauer's speech at the International Symposium of the R o y a l E n t o m o l o g i c a l Society (1976); and Michener's The S o c i a l Behaviour of the Bees (1974). An a r t i c l e on honeybee communication in l a s t year's A m e r i c a n Bee J o u r n a l by M. J. T u r e l l i l l u s t r a t e s the point: "When a food source is located l e s s than 100 m. f r o m the hive, the r e t u r n i n g s u c c e s s f u l scout p e r f o r m s the round dance T h i s dance gives only l i m i t e d information to the r e c r u i t . The d i r e c t i o n to the food source is not indicated at a l l , and the distance is shown only to be l e s s than 100 m. " 1 No elaboration on the race of bees to which such general statement might apply is offered. E i b l - E i b e s f e l d t (1970) l i s t s 25 m e t e r s as the t r a n s i t i o n distance. A thorough l i t e r a t u r e s u r v e y r e v e a l s c o n f l i c t i n g statements c o n c e r n i n g the a c c u r a c y of short-range f o r a g i n g and e s s e n t i a l l y no T u r e l l , M.J. 1976. A m e r i c a n Bee J o u r n a l 116(1), p. 17. information r e g a r d i n g the s e a r c h i n g behaviour. The p r e s e n t study therefore investigated the methods r e c r u i t s of the Italian honey bee, A p i s m e l l i f e r a l i g u s t i c a , use to locate a food source r e p o r t e d to them by other f o r a g e r s . The experiments included o l f a c t o r y , v i s u a l and sugar attractiveness of the food source and f o r a g i n g behaviour under sunny or cloudy skies and in shady o r sunny areas, as w e l l as distance, d i r e c t i o n , and height of the food source. L I T E R A T U R E R E V I E W 4 T h e r e is a body of work in the l i t e r a t u r e on honey bee communication and f o r a g i n g behaviour but v e r y few w orkers concerned themselves with f o r a g i n g over short distances. Recently, some questions have been raiseddwith r e s p e c t to the general statements that have been repeated over the l a s t 30 y e a r s . It may be worthwhile to s u m m a r i z e the work done up to this time in o r d e r to gain some insight into the d i v e r s i t y of the f o r a g i n g behaviour of the honey bee, as it is understood today. T h e r e were a few e a r l y studies on honey bee behaviour (von F r i s c h , 1914, 1915) but the communication of abstract information f r o m one ind i v i d u a l to another who then acts upon it became the r e s e a r c h target after von F r i s c h ' s r e p o r t in 1923. A c c o r d i n g to this report, a bee that d i s c o v e r s a near-by source of nectar (or honey o r sugar water), p e r f o r m s a round dance on the comb after her r e t u r n to the hive. She runs i n c c i r c l e s , a l t e r n a t e l y round to the right and round to the left. The bees who are near the dancer follow her, become excited, and f l y out in o r d e r to look f o r food of the same scent as the one they p e r c e i v e d f r o m the dancer's body. They f i r s t s e a r c h the immediate v i c i n i t y of t h e i r own hive in e v e r y d i r e c t i o n , i n c r e a s i n g the distance un t i l they find the food source. T h i s behaviour led von F r i s c h to conclude that at no time was distance or d i r e c t i o n of the food source indicated by this f o r m of dance. It has since been added that the sight of bees, bee scent s p e c i f i c to bees f r o m one hive, as w e l l as the product of their scent gland, o c c a s i o n a l l y thrust out at an abundant food source, also guide a r e c r u i t to the feeding place (for review, see von F r i s c h , 1971 and Gary, 1975). Twenty years la t e r , von F r i s c h expanded his observations on honey bee communication to longer distances. A w o r k e r honey bee that has d i s c o v e r e d a pr o f i t a b l e food source more than 100 m e t e r s f r o m the hive, indicates the d i r e c t i o n and distance of this source totthe other bees in the hive by p e r f o r m i n g a f i g u r e - e i g h t (or waggle) dance on the v e r t i c a l comb, such that the angle between the d i r e c t i o n of the dance and the v e r t i c a l is equal to the azimuth angle between the food source and the sun. On the alighting board in fr o n t of the hive, the str a i g h t p o r t i o n of the dance points d i r e c t l y to the food source. With i n c r e a s i n g distance, the number of complete waggle dances in a unit time de c r e a s e s while the number of waggle movements in the straight portion of the dance i n c r e a s e s . The number of dances per unit time is i n d i r e c t l y p r o p o r t i o n a l to the distance to the food source. The qualityoof the food is indicated by the l i v e l i n e s s and duration of the dance (von F r i s c h , 1947). Since that time many r e s e a r c h e r s have contributed.a great quantity of i n f o r m a t i o n on bee communication, much of which is reviewed in a book by von F r i s c h (1965, E n g l , t r a n s l . 1967a) who shared a Nobel p r i z e in 1973 f o r his contributions. Recently, some of the o r i g i n a l o bserva-tions and interpretations of honey bee behaviour have been supplemented, m o d i f i e d and in some cases questioned. 6 Waggle dance o r scent? Although the d i r e c t i o n a l and distance elements of honey bee dances have been d e s c r i b e d by a number of -workers f o r s e v e r a l species and races of the honey bee, Wenner and Johnson challenged the evidence supporting the dance language hypothesis and proposed that r e c r u i t m e n t is a c c o m p l i s h e d s o l e l y on the basis of odour information (Wenner, 1967; Johnson, 1967). While admitting that indications of d i r e c t i o n and distance are present in the waggle dance, the c r i t i c s maintain that these are neither understood nor acted upon by the bees. A c c o r d i n g to t h e i r hypothesis, only scent is s u c c e s s f u l l y communicated in the dance. R e c r u i t s leave the hive and drop 200, 300 m e t e r s o r m o r e downwind f r o m hive before commencing t h e i r s e a r c h f o r the odour both f r o m the bee which stimulated the r e c r u i t to leave and f r o m other bees s u c c e s s f u l at the same source, as well as f o r other odours they p e r c e i v e d on the dancer (Wenner and Johnson,^ 1967). Subsequently, the role of odour on the one hand (Wenner _et .al. , 1967; Wenner et al.. 1969; Johnson and Wenner, 1970; Wells and Wenner, 1971; New and New, 1971) and! of the waggle dances on the other (von F r i s c h , 1967b, 1968, 1974; Gould et aU, 1970; L i n d a u e r , 1971a, 1975; Segui-Goncalves, 1969) were investigated and r e - i t e r a t e d . D u r i n g the c o n t r o v e r s y , m o r e r i g o r o u s tests of bee dance communication have been devised. The l a t e s t of these studies by Gould (1974, 1975a,1975b, 1976) proves c o n c l u s i v e l y that bees use the dance in f o r m a t i o n r e g a r d i n g the distance and d i r e c t i o n of the food source f r o m the hive. In addition, Gould was able to show that the c o n f l i c t between the res u l t s of von F r i s c h and those of Wenner was at le a s t p a r t l y due to ex p e r i m e n t a l design. A c c o r d i n g to Gould, this might w e l l mean that r e c r u i t bees use the dance information when they are just s t a r t i n g to exploit a new food source but use scent, as Wenner proposed, when exploiting the same food source l a t e r . ' Dialects': In 1951, von F r i s c h o bserved that Apis m e l l i f e r a l i g u s t i c a has a slower dancing tempo than _A. m. c a r n i c a . Around that time, T s c h u m i (1950), and H e i n (1950) d e s c r i b e d a new f o r m of dance, the 'sickle dance', by which the Italian honey bees are able to indicate d i r e c t i o n even within short distances. B o c h (1957) extended these observations to fo u r additional r a c e s of Apis m e l l i f e r a : G e r m a n (A. m. m e l l i f e r a L . ), A f r i c a n P u n i c (A. m. inte r m i s sa), C a u c a s i a n (A. m. c auc a s ic a Grob. ) a^ nd Egyptian (A. m. f a s c i a t a L a t r . ). A l l six races were found to di f f e r in the details of the waggle dance, in p a r t i c u l a r the distance i n t e r v a l s at which the round and waggle dances are performed, the p r e s e n c e o r absence of the si c k l e dance, and the tempo of the waggle dance. These v a r i a t i o n s have been a p p r o p r i a t e l y r e f e r r e d to as 'dialects'. O nly the gray C a r n i o l a n bee did not p e r f o r m the d i r e c t i o n - i n d i c a t i n g s i c k l e dances, s t a r t i n g the waggle-tail dances when food source was 85 nv or f u r t h e r f r o m the hive. A l l other races indicated the location of the goal by means of the s i c k l e dance, which was t r a n s f o r m e d to the waggle-tail dance at greater distances. T h e i r s i c k l e (and waggle) dances have been ob s e r v e d at the following distances: A. m. m e l l i f e r a - 20 (65) m A. m. i n t e r m i s s a - 17 (65) m; A., m. c a u c a s i c a - 10 (35) m; A. m. l i g u s t i c a - 8 (35) m; A., rn. f a s c i a t a - 4 (12) m (Boch, 1957). When the Italian bees were f o r c e d to walk to t h e i r food source, they p e r f o r m e d waggle dances on the comb after they had -walked f o r the m i n i m u m distance of 2. 5 m (Bisetzky, 1957). Dance tempo o r sound? Although good evidence exists that distance information is contained in the waggle dance, it is not yet known how i t is transmitted. Von F r i s c h and co-workers found the duration of both the complete loop and of the waggle run, as w e l l as the number of-waggles p e r unit time, to be equally good means f o r conveying distance information. Wenner (1962) reports that the duration of the waggle, run and the time f o r sound production during this run as w e l l as the number of pulses per run are equally adequate c a r r i e r s of i n f o r m a t i o n c o n c e r n i n g the distance of the feeding station f r o m the hive. The frequency of these sound pulses is 200 c p S ' (Wenner, 1964), which must be distinguished-from the r a s p i n g sound a dancer produces with her y/ings (Esch, 1967). A t present, i t n s b e l i e v e d that the sound is p e r c e i v e d by the antennae (von Frisch,"; 1_967a; Wenner et •al-: , 1967) and not by the substrate 9 as was proposed e a r l i e r ( L i n d a u e r and K e r r , I960). Both von F r i s c h and Wenner noted the correspondence between the f r e q u e n c y of the dance sound (Wenner, 1962; E s c h j e t al_. , 1965) and the resonance of the f l a g e l l u m (Heran, 1959). The significance of sound production in honey bee communication is c u r r e n t l y being investigated in the U.S. A. Sun or landmarks? So f a r , nobody has questioned the m e c h a n i s m of d i r e c t i o n communication in the honey bee. Based on the bees' a b i l i t y to transpose the angle between sun and goal into g r a v i t a t i o n a l angle, this hypothesis makes it mandatory f o r bees to be able to p e r c e i v e sun's position in the sky. Von F r i s c h proposed and others repeated that the r e f e r e n c e point used in honey bee orientation is supplied by the sun's image (von F r i s c h , 1946) and that, under cloudy conditions, they bees can determine the sun's pos i t i o n f r o m the pattern of light p o l a r i z a t i o n , p r o v i d e d p a r t of the sky r e m a i n s c l e a r (von F r i s c h , 1951). Wellington (1955, 1974) noted that heat r e c e p t o r s , r a t h e r than the image of the sun, are m o re l i k e l y to be involved. However, the bees' a b i l i t y to detect temperature differences a c r o s s t h e i r heat recep t o r s is a d v e r s e l y affected by a i r c u r r e n t s , m aking th e i r heat compass l e a s t effective when it is most needed; i . e. , in the m i d d l e of an open space. Wellington points out that, a c c o r d i n g to his own observations, the m o s t effectiverrmethod available to insects f o r \ setting c o u r s e s a c r o s s open areas is d e r i v e d f r o m their a b i l i t y to p e r c e i v e p o l a r i z e d light when the overhead sky is completely c l e a r . Recently, e l e c t r o p h y s i o l o g i c a l studies on the compound eyes of the honey bee have been c a r r i e d out to determine s e n s i t i v i t y to the plane of p o l a r i z e d light (for a comprehensive review, see H o r r i d g e , 1975). As a result, the s e n s i t i v i t y to p o l a r i z e d light appears to be the most important (or sole) element in the c e l e s t i a l navigation of the honey bee. Wehner (1976) s u m m a r i z e d the lat e s t d i s c o v e r i e s in the f i e l d of p o l a r i z e d light p e r c e p t i o n by insects and proposed that the importance of the sun as a cue in bee navigation may w e l l have resulted f r o m the sun's lac k of p o l a r i z a t i o n rather than f r o m its r e l a t i v e brightness. When the sky is c:d)mpletely clouded over, making no p o l a r i z e d light available to the bees, the sun's position can be determined by the di s t r i b u t i o n of u l t r a v i o l e t light, p r o v i d e d the cloud l a y e r is thin (von F r i s c h , 1967a). Under thick clouds, conspicuous landmarks which are on the route may be used as ref e r e n c e points (von F r i s c h , 1967a; Lindauer, 1971b; Wellington, 1974). When both the sky and landmarks are available to the bees, landmarks are used over the sky compass only if theypprovide a continuous l i n e . However, when orientation cues both f r o m o p t i c a l m a r k s and f r o m the sky compass are lacking, the honey bee is incapable of o p t i c a l l y d e t e r m i n i n g the exact position of the food goal (Hoefer and Lindauer, 1975). 11 A t t r a c t i v e n e s s of the food source: Colour: von F r i s c h noticed that the c o l o u r which a bee has l e a r n e d to associate with food attractshher attention when she is s t i l l some distance away f r o m a food source connected with this colour, while the perfume she has l e a r n e d to associate with food attracts her attention when she comes near to a source that contains this scent (von F r i s c h , 1919). A c c o r d i n g to Ribbands (1955), c o l o u r and f o r m are r e s p o n s i b l e f o r approximately 8 0 % of the attractiveness of f l o w e r s to bees, while pollen, n e c t a r and perfume together are r e s p o n s i b l e f o r only 20%. C o mpared withnman's, honey bees' colour sense d i f f e r s in displacement of the s e n s i t i v i t y toward the short-wavelength end of the spectrum. Bees can dis t i n g u i s h ult r a v i o l e t , blue, blue-green and yellow (von F r i s c h , 1950; Daumer, 1958; Romoser, 1973). However, a c c o r d i n g to Mazokhin-Porshnyakov (1969), bees can also recognize green, yellow and orange. L e a v e s r e f l e c t light weakly and f a i r l y equally. Consequently, f l o r a l colour, whether v i s i b l e o r u l t r a v i o l e t , makes food v e r y conspicuous against the g r a y i s h background of foliage (Jones and Buchman, 1974). Butler (1951) reports that blue and yellow c o l o u r s at the food source are most attractive to a f l y i n g bee. F r e e (1970) compared the two c o l o u r s and found yellow to be m o r e attractive o v e r blue. However, out of a l l c o l o u r s that c o m p r i s e the bee spectrum, v i o l e t c o l o u r appears to be l e a r n e d most q u i c k l y (Menzel, 1967; Lindauer, 1971b). U l t r a v i o l e t patterns give f l o w e r s a definite f l o r a l c o lour beyond the v i s i b l e colour. T h ey are p r e s e n t on the petals and other f l o r a l p a r t s in a substantial number of f l o w e r i n g plants (Kevan, 1972; P r o c t o r and Yeo, 1972; Guldberg and Atsatt, 1975; T h o r p e t a l . , 1975). These patterns serve as nectar guides to many U V - s e n s i t i v e insects and as o r i e n t a t i o n cues f o r v i s i t i n g bees, e n s u r i n g m o s t e f f i c i e n t means of po l l i n a t i o n (Jones and Buchman, 1974). Recently, the p h y s i o l o g i c a l b a s i s f o r UV absorption and U V r e f l e c t a n c e on petals which f o r m s patterns and guides has been worked outt(Brehm and K r e l l , 1976). Shape: Honey bees are flower constant; i . e . they come to the same fl o w e r species f o r hours o r days, as long as the b l o s s o m s open t h e i r c o r o l l a s . The outline of a flower is apparently r e l a t i v e l y unimportant, whereas the degree of d i s s e c t i o n , o r the amount of contour per unit a r e a of the flower is e x t r e m e l y important ( F r e e , 1970; Anderson, 1972; Jones and Buchman, 1974). When models were tested, s o l i d f i g u r e s were e a s i l y distinguished f r o m open o r divided ones (von F r i s c h , 1950). Out of c i r c u l a r , t r i a n g u l a r , square, petaloid, and star-shaped models, the models with d i s r u p t i v e outlines were m o s t at t r a c t i v e . M o d e ls with nectar guides were much m o r e effective than models without ( F r e e , 1970). Other v i s u a l attractions: A r e c r u i t approaching a feeding station is often attracted by a silhouette of another bee. Kalmus (1954) o b s e r v e d that t r a i n e d f o r a g e r s , coming f r o m a hive, settled d i r e c t l y on a bee d r i n k i n g alone on a dish, although there was plenty of r o o m in that 13 p a r t i c u l a r d i s h and s e v e r a l other dishes. In fact, the attracta'nt bee does not have to be li v e or three-dimensional; dead bees as well as flat , cut-out paper bees under glass stimulated f o r a g e r s to land. Scent: Whatever the quality which f i r s t attracts a scouting bee to investigate an object c l o s e l y , the bee is u n l i k e l y to check f u r t h e r unless she is able to s m e l l some perfume f r o m i t (Butler, 1951; 1971). S p e c i f i c flower scent is recognized by o l f a c t o r y r e c e p t o r s of the plate organs on the antennae (von F r i s c h , 1950). Von F r i s c h proposed that bees' o l f a c t o r y acuity is s i m i l a r to that of man and that substances without odour f o r us are likewise odourless f o r bees . T h i s statement has been accepted by some workers (e. g. M o r s e , 1972); however, Ribbands (1955) c l a i m s that the o l f a c t o r y threshold of the honey bee is lower thannman's. A c c o r d i n g to him, bees can be tr a i n e d to red c u r r a n t flowers, thought inodourous to use as w e l l as being able to dis t i n g u i s h between a pure scent and a 35!bl m i x t u r e of that scent and another one. In addition, body odours of t h e i r c omrades are rec o g n i z e d at concentrations m uch below man's threshold of perce p t i o n . N e c t a r guides of some f l o w e r s are not only of dif f e r e n t c o l o u r than the r e s t of the flower, but they also contain sap spots having a different scent o r the same scent at a higher intensity (von F r i s c h , 1950). The odour stimulus is strong enough to b r i n g about a response to bee dances ( F r e e , 1969), but o l d e r experienced f o r a g e r s apparently respond only to those w o r k e r s c o l l e c t i n g f r o m the plant source on which the o l d e r 14 bees have p r e v i o u s l y foraged. The older bees may respond in this way without actually following the dance. E x p e r i e n c e d bees also tend to congregate on different areas of the brood comb, where dancing of 'their group' o c c u r s (von F r i s c h , .1950; Wenner, 1971). However, membership in such f o r a g i n g groups is not permanent. As a p a r t i c u l a r flower wanes, individual bees change to other kinds of f l o w e r s . A n o c c a s i o n a l bee may simultaneously belong to two o r m o r e f o r a g i n g groups (von F r i s c h , 1974). Nasanoff gland odours as w e l l as body odours can also induce c l u s t e r i n g at food sources(Kalmus, 1954). E v e n though it is often n e c e s s a r y f o r a bee to approach within 2-3 c m before she can d i s c e r n any perfume a flower may p o s s e s s (Oettingen-Spielberg, 1949), bees p r e f e r the scent over the c o l o u r ( K r i s t o n , 1973) if both scent and c o l o u r have s i m i l a r degrees of a t t r a c t i v e n e s s . Koltermann(1974) studied l e a r n i n g and forgetting in honey beesrand concluded that scent had more importance than colour, time of day, o r f o r m . Sugar concentration: Sugar l e v e l , n e c e s s a r y to stimulate dancing in the hive, v a r i e s with flower species, season, and weather conditions (Ribbands, 1949; Lindauer, 1953). . Indication of 'up' o r 'down': T h e r e is no evidence in the l i t e r a t u r e that honey bees can communicate the height of food r e l a t i v e to the ground l e v e l . R esults of experiments on height indication by Apis m e l l i f e r a carnica-and A. m. l i g u s t i c a obtained by von F r i s c h et _al_. (1953) were negative. 15 M A T E R I A L S AND M E T H O D S The Italian bees used in this study, Apis m e l l i f e r a l i g u s t i c a Spin. , were obtained f r o m C a l i f o r n i a through a l o c a l s u p p l i e r as a two-pound package (approx. 8,000 workers and one queen) at the end of A p r i l , 1976. The package was hived in a two-super Dadant-size hive and supplied with sugar solution, pollen substitute and antibiotics as r e q u i r e d . In a p e r i o d of s i x weeks, the group p r o g r e s s e d to a f a i r l y strong colony f r o m which s e v e r a l f r a m e s of bees could be removed without s e r i o u s l y affecting f u r t h e r development. On June 7th four f r a m e s were placed in a s p e c i a l l y built e x p e r i m e n t a l hive and a new queen was introduced. The colony hive was located on the U n i v e r s i t y of B r i t i s h C o l u m b i a campus, in the a p i a r y of the Department of P l a n t Science. Throughout the summer, the , e x p e r i m e n t a l hive was stationed in a home garden in Vancouver; in e a r l y f a l l , when robbing by bees f r o m the neighbourhood became a s e r i o u s hindrance to experimental work, the hive was moved to a garden in Burnaby (Plate I). M o s t of June was spent t r a i n i n g bees to respond to a r t i f i c i a l food sources (Plate II). Two-molar solution was used in a l l experiments unless otherwise speci f i e d . Open watch glasses (von F r i s c h , 1967a) grav i t y f e e d e r s (Gary "and W i t h e r e l l , 1971) and grooved j a r s (Renner, 1959) are commonly used as feeding dishes. In this study, the need f o r their constant replacement and p r o p e r washing in o r d e r to dispose of bee- and food- scents was avoided by u s i n g paper-lined, disposable P l a t e I. E x p e r i m e n t a l hive. P l a t e II. T r a i n i n g honey bees to forage at experimental food sources. 18 aluminum dishes 7 c m in d i a m e t e r and 0. 5 c m deep. T h e i r c o l o u r arrangement (purple l i n e r , d i s h sit t i n g on a yellow paper 10 x 10 cm) was chosen in accordance with the most attractive b e e - c o l o u r s r e p o r t e d in the l i t e r a t u r e (Butler, 1951; F r e e , 1970). When scent was used, one pipette drop was placed in 10 m l of sugar solution. Scents were obtained as a c o u r t e s y sample f r o m Sel-Win C h e m i c a l Co. o r were purchased f r o m a l o c a l H e a l t h - F o o d Store. Bees were m a r k e d by p l a c i n g a dot of paint on th e i r thorax either when they l e f t the hive o r while they were at the food source. The paint d r i e d before their r eturn to the hive (Plates III and IV). C o l o u r e d l a c q u e r s d i s s o l v e d in alcohol o r colour tags (von F r i s c h , 1967a; Jay, 1969) o r pieces of c e l l u l o i d d i s s o l v e d in acetone (Dhaliwal and Sharma, 1974) are widely used by bee r e s e a r c h e r s , but p r e m a t u r e d r y i n g of the applicators presents a p r o b l e m . A m a r k e r pen f r o m M e t r o n Optics, C a l i f o r n i a , recommended by Spangler (1974), was used instead and proved to be a v e r y valuable tool. Caution had to be e x e r c i s e d on hot days, however, when the contents of the pens were too fluid, often s o i l i n g the bees' wings. A p p r o x i m a t e l y 5,000 bees were m a r k e d in the c o u r s e of the experiments. To start an experiment, a food source was set up at a p r e - d e t e r m i n e d distance and d i r e c t i o n f r o m the hive. The time of a r r i v a l of the f i r s t f o r a g e r ( s ) was noted and the number of bees at the d i s h was taken every five minutes during the total p e r i o d of exposure. A one half-hour to P l a t e III. One m a r k e d f o r a g e r and one unmarked r e c r u i t at the feeding dish. P l a t e TV. M a r k e d f o r a g e r s crowding at the feeding dish. 20 21 one hour pause was allowed before the food source was moved. At the end of the season, in October, 1976, bees f r o m the e x p e r i m e n t a l hive were re-united with th e i r parent colony. / 22 R E S U L T S 1. V i s u a l a t t r a c t i v e n e s s of food s o u r c e . (a) D i s c o v e r y time: Out of seven dishes that were made a v a i l a b l e to the bees at the same time, dishes offe r i n g the greatest v i s u a l contrast were found in the shortest p e r i o d of time, l e s s than 3.5 minutes after exposure (dishes A and B in T a b l e I and F i g u r e la) . T h e s e dishes combined yellow and purple, c o l o u r s . D i s h e s with a single c o l o u r were d i s c o v e r e d a p p r o x i m a t e l y 7 to 15 minutes after exposure. P u r p l e - or yellow-coloured dishes were d i s c o v e r e d f a s t e r than brown-, r e d - or b l a c k - coloured d i s h e s . (b) Number of scouts: A s can be seen f r o m F i g u r e l a , the number of scouts a r r i v i n g at the feeding places did not d i f f e r greatly among the seven d i s h e s . (c) Number of r e c r u i t s : On the other hand, the total number of r e c r u i t s that a r r i v e d at the r e s p e c t i v e dishes d u r i n g the r e m a i n d e r of the hour v a r i e d f o r s e v e r a l dishes: yellow (D) r e c e i v e d the most (26.2) and brown (G) the least number of r e c r u i t s (14.67) (Table I; F i g u r e la). ' (d) Number of bees 30 and 60 minutes after exposure: A to t a l l y different p i c t u r e of r e c r u i t m e n t can be obtained when total numbers of bees at each of the seven dishes a r e observed at two i n t e r v a l s , 30 and 60 minutes after the i n i t i a l exposure of the T a b l e I. A t t r a c t i v e n e s s of v a r i o u s c o l o u r s and shapes at food source. D i s h Yellow paper, (cm).. D i s h c.olojar Types of food source (3 m f r o m hive, 30 c m f r o m each other) A B C D K~> F G 15x15 8x8 8x8 purple purple purple yellow red black brown T o t a l exposure ^ ^ 6 ( ) 6 Q ^ 6 Q 6 Q time (minutes) Scout's d i s c o v e r y 3.22 3.44 7.22 9.11 14.4.4 14.77 11.66 time (minutes)* ±0.99 ± 0 . 9 5 ±1.62 ±1.21 ±1.30 ±1.19 ±1.66 No. of scouts and/or 2.11 1.55 1.33 1.11 . 1.22 1.44 1.11 scouts r e t u r n i n g ±0.26 ± 0 . 2 4 ±0.16 ±0.11 ±0.14 ±0.24 ±0.11 T o t a l no. of 23.0 19.88 19.66 26.22 16.88 18.44 14.66 r e c r u i t s ±3.33 ±2.50 ±2.0 ±2.73 ±1.74 ±2.31 ±1.80 No. of bees on d i s h 8.77 8.88 5.00 2.55 1.33 1.0 1.77 30 minutes after ±1.80 ±1.96 ±1.02 ±1.02 ±0.33 ±0.37 ±0.61 exposure No. of bees on d i s h 10.55 12.66 12.55 20.55 17.66 11.22 12.88 60 minutes after ± 3 . 4 4 ± 3 . 0 5 2.53 ±3.76 ±1.71 ±1.02 ±1.90 exposure n= 9 N O T E : standard e r r o r s used in this and a l l the other tables, '''including time to sit down at the d i s h and take up food. F i g u r e l a . Scout's d i s c o v e r y time and r e c r u i t m e n t at seven v i s u a l l y different food sources d u r i n g a 60-minute p e r i o d . Number of scouts and/or scouts r e t u r n i n g I 1 T o t a l number of r e c r u i t s • Scout's d i s c o v e r y time F i g u r e lb. Number of bees v i s i t i n g seven v i s u a l l y different food s o u r c e s 30 and 60 minutes after exposure. I I T o t a l number of bees on d i s h 30 minutes after expo sure i 1 T o t a l number of bees on d i s h 60 minutes after exposure F o o d source = dishes A, B, C, D, E, F, and G as per T a b l e I. Number of bees u> o U l o Ul o m o m —I 1— 1 1 _ . 1 I I I • 4 8 o CO O I 1 I — i -m D i s c o v e r y time - minutes U i 26 food source. T a b l e I and F i g u r e lb r e v e a l that dishes -with frequent scout v i s i t s and subsequent v i s i t s of r e c r u i t s during the i n i t i a l 30-minute p e r i o d showed only a r e l a t i v e l y s m a l l i n c r e a s e in r e c r u i t m e n t in the following 30 minutes (dishes A and B). On the other hand, dishes with slow i n i t i a l r e c r u i t m e n t were v i s i t e d by a greatly i n c r e a s e d number of bees in the second half of the total exposure p e r i o d (dishes G - G). 2. O l f a c t o r y attractiveness of food source. Six scents, o f f e r e d in dishes of id e n t i c a l c o l o u r arrangement, were tested f o r their attractiveness to the bees. (a) D i s c o v e r y time: The time f o r the scout to d i s c o v e r a food source is taken as the time between the i n i t i a l exposure and the time a scout sits down on a d i s h and takes up sugar solution. Although hovering/ taking-off behaviour was o b s e r v e d above a l l six dishes almost equally, the food was taken up f a s t e s t in dishes containing orang,e, peppermint and cinnamon o i l s (Table II; F i g u r e 2). Alf.al£a honey was not n e a r l y as stimulating as the three flower scents.' L avender was, even less, attractive, and anise seed o i l was taken only twice. (b) Number of scouts and recruitment: Number of scouts per d i s h ranged f r o m 3.9 on peppermint-scented dis h to 0. 3 on anise-scented dish '(Table II). The total number of r e c r u i t s followed the same trend, with the highest r e c r u i t m e n t o c c u r r i n g at peppermint-, orange- and cinnamon-scented dishes and none at the d i s h with anise seed o i l ( F i g u r e 2). T a b l e II. A t t r a c t i v e n e s s of v a r i o u s scents at food source. A l f a l f a x values Scent: P e p p e r m i n t Orange Cinnamon • Lavender An i s e - ft- o Honey-Distance f r o m hive (meters) scouts r e t u r n i n g n 12. 09 11. 61 1.1. 74 4- 23 7. 62 6.75 T o t a l exposure _ „_ A n , . . » 21. 67 22. 50 25. 50 28. 33 28. 33 40.71 time (minutes) Scout's d i s c o v e r y 2. 44 1.92 2. 55 3. 60 4. 33 4.14 time (minutes) +0.44 +0. 36 +0. 60 +0.85 +0. 53 +0. 51 No. of scouts and/or 3. 89 2.42 1. 70 1.00 0. 78 0. 29 + 0. 81 +0. 87 +0. 56 +0. 29 +0. 28 +0. 18 T o t a l no. of r e c r u i t s 6. 89 5. 92 5/00 3. 33 3. 89 0.00 + 0.90 +1. 08 +0.88 +0. 33 +0. 70 12 10 F i g u r e 2. Scout's d i s c o v e r y time and r e c r u i t m e n t at s i x olf a c t o r i l y d i f f e r e n t food s o u r c e s . Number of s c o u t s and/or s c o u t s r e t u r n i n g I I T o t a l number of r e c r u i t s • Scout's d i s c o v e r y time 30 3. E f f e c t of sugar concentration on r e c r u i t m e n t . v (a) D i s c o v e r y time: When three v i s u a l l y i d e n t i c a l dishes, two of them with v e r y weak sugar solution (1/16 M) and one with a strong sugar solution (2 M), were offered to the bees, a l l three were d i s c o v e r e d d u r i n g the f i r s t two minutes (Table III). (b) Number of scouts a r r i v i n g at these dishes was c l o s e to two i n a l l c a s e s . However, the d i s h containing one drop of peppermint or orange scent r e c e i v e d a s l i g h t l y higher, number of scouts than the two unscented dishes' (Table III). (c) Number of r e c r u i t s : R e c r u i t m e n t o c c u r r e d only at the food s o u r c e with a 2-molar sugar concentration ( F i g u r e 3). While this d i s h r e c e i v e d 12.4 r e c r u i t s , r e c r u i t m e n t to an i d e n t i c a l d i s h with 1/16-molar solution was v i r t u a l l y n i l . 31 Table III. E f f e c t of sugar concentration in the feeding solution on r e c r u i t m e n t . x" values Sugar solution (5 m f r o m hive) L/16 M Vl6 M with 1 drop scent 2 M T o t a l exposure time (minutes) 30 30 30 Scout's d i s c o v e r y time (minutes) 1. 44+0.17 1.22+0.14 1. 88+0.42 No. of scouts and/or scouts r e t u r n i n g 1. 77+0. 2 2a 2.33+0.28^ 1. 66+0. 23 a T o t a l no. of r e c r u i t s 0.33+0.16b 0.44+0.24 b 12. 44+1. 45 a n = 9 z M e a n sepa r a t i o n by Duncan New M u l t i p l e Range Test, 5 % l e v e l , a, b In this and subsequent tables, s i m i l a r s u p e r s c r i p t s in the same row indicate no sig n i f i c a n t d i f f e r e n c e . F i g u r e 3. E f f e c t of sugar c o n c e n t r a t i o n in the. feeding solution on r e c r u i t m e n t over a 30-minut e p e r i o d . a = 1/1 6 M sugar c o n c e n t r a t i o n (o= s c o u t s , " = r e c r u i t s ) A = 2 M sugar c o n c e n t r a t i o n (A = scouts, A s~ r e c r u i t s ) 12 1 A u h Scout's discovery time - minutes I 34 4. V i s u a l vs o l f a c t o r y a t t r a c t i v e n e s s of food s o u r c e . T h e c o m p a r a t i v e a t t r a c t i v e n e s s of colour and scent was tested by: (a) b r a c k e t i n g a v i s u a l l y a t t r a c t i v e d i s h with two scent-containing dishes; and (b) by p l a c i n g one v i s u a l l y a t t r a c t i v e d i s h and one o l f a c t o r i l y a t t r a c t i v e dish, each with a different sugar concentration, at the same distance f r o m the hive, but se p a r a t i n g them by a distance greater than the distance of the food s o u r c e f r o m the hive. (a) Bracketing: In c o n t r o l experiments, the v i s u a l l y a t t r a c t i v e d i s h was d i s c o v e r e d a l m o s t three times f a s t e r than two food sources hidden in dandelion l e a v e s . N e a r l y equal numbers of scouts came to a l l t h r e e dishes, but the number of r e c r u i t s was much higher at the v i s u a l l y a t t r a c t i v e d i s h than at the g r a s s - c o v e r e d d i s h (Table IVa; F i g u r e 4a) . A f t e r one drop of peppermint o i l was added to the two dishes concealed in dandelion leaves, the scoutis d i s c o v e r y t i m e dropped to a p p r o x i m a t e l y Z minutes. The number of scouts a r r i v i n g at these dishes i n c r e a s e d v e r y slightly, but there was a noticeable i n c r e a s e in the total number of r e c r u i t s (Table IVa; F i g u r e 4a). While some bees remained faithful to the i r o r i g i n a l feeding site, others t r a n s f e r r e d to o l f a c t o r i l y a t t r a c t i v e dishes ( F i g u r e 4a; P l a t e V). (b) Two food sources, greater distances apart, with one having the v i s u a l c h a r a c t e r i s t i c s of a food source, but containing v e r y weak sugar solution (1/16 M), whereas the other, containing a s t r o n g sugar solution (2 M), is hidden in the grass: 35 Plate V. Marked forager looking for food at visually unattractive location. 36 Table IV. V i s u a l vs. o l f a c t o r y a t tractiveness of food source in a sh o r t p e r i o d . 2 (a) Two inconspicuous sources 30 c m right and l e f t of c e n t r a l conspicuous source. 2 M sugar solution (8 m f r o m hive) in: x values F F F 1 2 *3 purple d i s h dandelion dandelion leaves leaves T o t a l exposure C 15 15 15 time (minutes) E Scout's d i s c o v e r y C 1. 85+0. 30 5. 42+1.13 6.10+1.17 time (minutes) E 1. 28+0. 18 2. 0 +0. 53 2.14+0.66 No. of scouts and/or C 1. 42+0. 2 0 a 0. 85+0. 13 a 1.44+0. 2 6 a scouts r e t u r n i n g E 1. 42+0. 2 0 a 1.42+0. 29 a 1. 28+0.18 a T o t a l no. of C 11. 42+1. 5 5 a 2.0 +0.78 b 1. 85+0. 7 3 b rec r u i t s E 8.14+1. 0 5 a 10. 85+1. 3 8 a' 11. 85+1. 03 a n = 7; z M e a n se p a r a t i o n by Duncan New M u l t i p l e Range Test, 5 % l e v e l . C - c o n t r o l E - experiment (1 drop of peppermint scent added to F £ and F3) 37 Table IV. V i s u a l vs. o l f a c t o r y attractiveness of food source i n a short p e r i o d (continued). (b) One conspicuous and one inconspicuous source having two sugar concentrations and located f a r t h e r : v f r o m each other (5 m) than f r o m the hive (3 m )..,. F F _ 1 2 x values . i/16 M sugar solution 2 M sugar solution in purple d i s h on dandelion leaves T o t a l exposure C time (minutes) E 15 15 Scout's d i s c o v e r y C 1. 42+0. 20 3. 85+0. 59 time (minutes) E 1.14 + 0.13 1.00+0.51 No. of scouts and/or C 1. 85+0. 2 6 a 1.28+0.18 a scouts r e t u r n i n g E 1.42+0.-20 a 2. 28+0.41 a T o t a l iib. of C G. 28+0.10 b -2.42+0.29 a r e c r u i t s E 0. 42+0. 2 9 b 15. 57+1. 37' a n = 7 C - c o n t r o l E - experiment (1 drop of peppermint scent added to F2) F i g u r e 4a. Scout's d i s c o v e r y time and r e c r u i t m e n t to one v i s u a l l y a t t r a c t i v e and two o l f a c t o r i l y a t t r a c t i v e food s o u r c e s in a 15-minute p e r i o d . 2M sugar s o l u t i o n in: p u r p l e d i s h ( F^) and d a n d e l i o n leaves ( F £ and F ^ ) . I 1 C o n t r o l E x p e r i m e n t (1 drop of peppermint scent added to F £ and F^) F i g u r e 4b. Scout's d i s c o v e r y time and r e c r u i t m e n t to one v i s u a l l y attractive and one o l f a c t o r i l y attractive food source in a 15-minute p e r i o d . F p 1/16 M sugar solution in purple dish; F^: 2M sugar solution in dandelion leaves. C o n t r o l I 1 E x p e r i m e n t (1 drop of peppermint scent added to F^) S = scouts R = r e c r u i t s • = scouts' d i s c o v e r y time 4^ I CO I co 4 c o 4^ Number of bees ox co 4 c o t co 4 IN) co CO 4 CO cr D i s c o v e r y time - minute 40 1. C o n t r o l . A v i s u a l l y a t t r a c t i v e d i s h with weak sugar solution was d i s c o v e r e d in l e s s than two minutes, whereas the strong sugar solution in dandelion leaves was not d i s c o v e r e d until a l m o s t four minutes after exposure. Although the numbers of scouts v i s i t i n g the two dishes did not d i f f e r greatly, the number of r e c r u i t s was higher at the strong sugar solution than at the v i s u a l l y a t t r a c t i v e food s o u r c e (Table IVb; F i g u r e 4b). 2. E x p e r i m e n t . The above r e l a t i o n s h i p was r e v e r s e d when a drop of peppermint o i l was added to sugar solution in dandelion leaves: the d i s c o v e r y t i m e of the olfactorllyliattr-active^dish d e c r e a s e d to one minute, the number of scouts that a r r i v e d to it was s l i g h t l y higher than at the v i s u a l l y a t t r a c t i v e d i s h (F\), and the total number of r e c r u i t s was much higher than at F^ (Table IVb; F i g u r e 4b). 41 5. Use of landmarks and p o l a r i z e d light by f o r a g e r s . On a day with high overcast, a food source was moved f r o m a p o s i t i o n c l o s e to the c o r n e r of a flower bed and placed d i r e c t l y behind the bed, so that f l o w e r s approximately 1 meter high and garden netting approximately 2 m e t e r s high obscured the food source f r o m the hive. S h o r t l y afterwards, while the o v e r c a s t s t i l l remained, two dis t i n c t groups of f o r a g e r s were observed: (a) bees that came to the di s h behind the flower bed and netting v i a the old site (Route A in F i g u r e 5) and (b) those that came v i a the other c o r n e r of the fl o w e r bed (Route B). When the d i s h behind the flower bed was r a i s e d to head height on a step-ladder, the bees continued to come to it around the c o r n e r s of the flower bed as long as the overhead sky was obscured. And if an o b s e r v e r stood beside the ladder, the bees c i r c l e d them at head height, investigating the "landmark" as long as the o b s e r v e r r e m a ined within a m e t e r of the food source. But when the overhead sky c l e a r e d , some bees returned to the hive d i r e c t l y through the netting at head height, and within a f e w minutes the f o r a g e r s gave up "landmarking" f o r straight flights to and f r o m the hive (Route C). When the d i s h was set on the ground again, and they f i n a l l y located it, they continued t h e i r " b e e - l i n e " f l i g h t s . F i g u r e 5. Map of e x p e r i m e n t a l area, showing f o r a g e r f l i g h t paths to a relocated food source (behind flower bed). See text f o r d e s c r i p t i o n of routes A, B, and C. 43 44 6. E f f e c t of location of food source on foraging: sunlit vs shadowed  area: An i n t e r e s t i n g phenomenon was observed when two dishes were placed at the same distance f r o m the hive, one in a sunlit a r e a and the other under widely s p r e a d branches of a catalpa tree (Plate VI). (a) Under c l e a r conditions: Invariably, dishes in the sunny a r e a were investigated and v i s i t e d by scouts much more r e a d i l y than dishes in the shadow. Though the i n i t i a l d i s c o v e r y time f o r a d i s h placed on the boundary of the two areas was m o re than five minutes, time spent to find and take up food at the r e l o c a t e d food source was much sh o r t e r when the d i s h was moved to the sunlit a r e a (1. 3 minutes), than when it was moved to shadow (4. 2 minutes). The numbers of scouts and ' - : i r e c r u i t s were higher both on the boundary and in the sunlit area, compared with the number of bees that came to the d i s h in the shade (Table Va; F i g u r e 6a). (b) Under cloudy conditions: The above di s t i n c t i o n with r e s p e c t to the location of the food source disappeared as soon as the sky clouded over and there was little or no boundary between the two areas. On such days, bees foraged with equal zest in a l l locations (Table Vb; F i g u r e 6b). 45 P l a t e VI. Boundary between the sunlit (left) and shaded (right) areas in the e x p e r i m e n t a l garden. 46 Table V. F o r a g i n g and r e c r u i t i n g a c t i v i t i e s z (a) under c l e a r conditions when two i d e n t i c a l food sources a r e set in.two d i s t i n c t locations:. (i) in a sunlit a r e a (Light) and (ii) in shadow/(Dark) L o c a t i o n of food source x values Initial p o s i tion P o s i t i o n changed to (3. 5 m to (10 m f r o m hive) right and lef t f r o m i n i t i a l position) on D a r k / L i g h t boundary to L i g h t to D a r k T o t a l exposure time (minutes) 21. 50 15. 00 15. 00 Scout's d i s c o v e r y time (minutes) 5. 30+1. 23 1. 30+0. 15 4.20+0.79 No. of scouts and/ o r scouts r e t u r n i n g 8. 40+1. 61J 7.40+1. 0 7 a 2. 30+0. 5 6 b T o t a l no. of r e c r u i t s 5. 30+1.14a 6. 00+0.85.a 2. 00+0. 38 b n = 10 ; r r - . i , r . (b) under cloudy conditions when there is no d i s t i n c t i o n i n the i l l u m i n a t i o n of two locations of two. i d e n t i c a l food sources T o t a l exposure time (minutes) Scout's d i s c o v e r y time (minutes) No. of scouts and/ o r scouts r e t u r n i n g 23. 00 6. 00+0. 96 12. 00+1. 0 3 a T o t a l no. of r e c r u i t s 6. 75+0. 75 a 15. 00 1.50+0.19 15. 00 1. 62+0.18 7. 87+0. 99 a 8. 25+0. 88 a 4.50+0.76 a 4.12+0. 5 8 a n = 8; z M e a n separ a t i o n by Duncan New M u l t i p l e Range Test, 5 % l e v e l . F i g u r e 6a. Scout's d i s c o v e r y time and r e c r u i t m e n t under c l e a r conditions when two iden t i c a l food sources are set in two di s t i n c t locations: (i) in a sunlit a r e a (Light) and (ii) in shadow (Dark). F i g u r e 6b. Scout's d i s c o v e r y time and r e c r u i t m e n t under cloudy conditions when there is no dis t i n c t i o n in the i l l u m i n a t i o n of two locations of two id e n t i c a l food s o u r c e s . Scouts Recruits • D i s c o v e r y time \ 49 7. Food relocation and searching behaviour: When a food source is moved from one location to another, bees search until the new location is found. The new location is found by arriving at old location, circling there, and then moving in the right or wrong direction along the arc of the distance at which the original source was located from the hive. As they fly along thisaarc, they either zig-zag or circ l e every few seconds , searching for the new site. Once the new source is found, the bees continue to arrive via the old location for nearly 30 minutes. Later, they approach the feeding site directly from the hive (Table VI; Figure 7). At the initial site, the number of scouts and recruits increased steadily during the 30-minute exposure (Figure 7a). Following relocation, foragers that found the new site arrived via the initial location during the f i r s t 15 minutes, but began switching over to the direct routeduring the next 15 minutes (Figure 7b). Recruitment was low immediately after the relocation, but increased in the latter half of the 30-minute observation period. The number of recruits arriving directly from the hive was much higher than the number arriving via the initial location (Figure 7c). Table VI. S e a r c h i n g behaviour f o l l o w i n g r e l o c a t i o n of food source. T i m e (minutes) Mean number of bees at i n i t i a l l o c ation (9. 6 m_- f r o m hive) Mean number of bees at relocated food (4. 7 m- f r o m i n i t i a l location) source O r i g i n a l scouts and r e t u r n i n g f o r a g e r s R e c r u i t s O r i g i n a l scouts and ret u r n i n g f o r a g e r s R e c r u i t s V i a i n i t i a l l ocation D i r e c t l y f r o m hive V i a i n i t i a l l o c a tion D i r e c t l y f r o m hive I 1 0. 54+0. 21 0.0 4. 91+0. 81 0. 0 0. 0 0. 0 5 2. 82+0. 58 0.54+0.25 8.18+0. 98 0. 09+0. 09 1. 27+0. 27 0.18+0.12 10 5. 73+0. 85 2.64+0.82 12.55+1. 37 0.45+0.21 2.45+0. 39 0.91+0.25 15 10.18+1. 21 5. 27+L.05 12. 73+1. 29 2. 60+0. 61 3.36+0.53 1.45+0. 39 30 13. 64+1. 77 8. 36+1. 54 8.45+1. 95 10.45+2.18 1. 64+0. 62 4.73+0.69 n A 11 F i g u r e 7a. Number of scouts (•) and r e c r u i t s (A ) at the i n i t i a l l o c a tion of the food during a 30-minute i n t e r v a l . F i g u r e 7b. Number of scouts a r r i v i n g at- relocated food source v i a the i n i t i a l l o c ation (•) or d i r e c t l y f r o m hive (o) during a 30-minute i n t e r v a l after r e l o c a t i o n . F i g u r e 7c. Number of r e c r u i t s a r r i v i n g at relocated food source v i a the i n i t i a l location (*>)„ o r d i r e c t l y f r o m hive ( A ) during a 30-minute i n t e r v a l after r e l o c a t i o n . 52 53 8. Height indication. When two food sources were set up at the same distance and d i r e c t i o n f r o m the hive, but at two dif f e r e n t heights (0 and 170 cm), two di s t i n c t groups of f o r a g e r s formed, each v i s i t i n g only one source. T h e r e was v e r y l i t t l e mix-up between the two groups, whether the distance f r o m the hive was 10 m ('close'), 20 m ('far') (Table VII), or 50 m (Table VIIIand F i g . 8). L i n e 1 in Table VII shows that what l i t t l e s p i l l o v e r there was at the shortest distance f r o m the hive was due to 'Low' f o r a g e r s being attracted upward. When the heights of the two food sources were gra d u a l l y brought together and the sources were switched and then r e - s e p a r a t e d (line 3 in Table VII), m i x i n g of f o r a g e r s i n c r e a s e d slightly, compared with two sources always kept 170. 2 c m apart (line 4 in T a b l e VII). A t the same time, the d i s h and paper p r e v i o u s l y v i s i t e d by one group of f o r a g e r s were v i s i t e d without hesitation by the other group. In t r a v e l l i n g to the i r r e s p e c t i v e feeding sites, 'Low' f o r a g e r s flew l e s s than 30 c m above ground, whereas 'High' f o r a g e r s began to c l i m b s t e a d i l y as soon as they left the hive, until they l e v e l l e d off approximately 1. 5 m above the ground. T h e y did so even under windy and co o l conditions, when they flew 50 m f r o m thehhive over an open space to the high source. When only one food source was offe r e d at a height of 120 cm, and an o b s e r v e r was sitting near the post, bees a r r i v e d at the c o r r e c t height, hovering above the observer's head. On the other hand, bees going T a b l e VII. R e c r u i t m e n t and f o r a g e r mix-up at two identical food sources located at the same distance and d i r e c t i o n f r o m the hive but at two different heights (0-and < 170 cm,). Height Distance ; x " v a l u e s f o r locations D i f f e r e n c e (cm) f r o m hive (m) E x p o s u r e L o w High t i m e . 'high* 'low' — — / • \ r e c r u i t s „, r e c r u i t s r range x range x (min.) t f o r a g e r s f o r a g e r s n 0-170. 18 150. 87 0-170.18 97. 09 0*142. 24 76. 03 (1 switch') 170.18 170.18 8. 84-10.36 9.44 ('close') 16. 76-24.38 19. 52 ('far') 10.36-24.38 19.10 8.84-20il2 15.84 60 60 60 60 18. 20 +4. 36 22. 22 +2. 51 22. 60 +2. 08 19. 00 +4.99 0. 00 2. 66 + 0. 72 2. 66 +0. 83 14. 00 +4.43 20. 22 +1.99 22. 00 +1. 67 1. 8 5 +1. 35 2.16 18 +0. 59 2.46 15 +0. 68 1. 00 14.25 0. 25 8 + 0. 67 +3.88 +0.24 Table VIII. R e c r u i t m e n t and f o r a g e r mix-up at two iden t i c a l food sources located at the same distance and d i r e c t i o n f r o m the hive but at two different heights (0 and 170 cm), when distance is gradually increased. Number, of bees "at: Height Distance E x p o s u r e Low High D i f f e r e n c e f r o m hive t i m e ' 'high' 'low' (cm), • (mj), (min.) recruxts f o r a g e r s . r e c r u i t s • f o r a g e r s 170. 18 1. 5 90 55 0 15 0 7 25 11 0 12 0 13 15 66 1 35 0 25 20 21 3 8 3 50 15 13 0 15 1 F i g u r e 8. Re c r u i t m e n t (solid symbols) and f o r a g e r mix-up (empty symbols) at two id e n t i c a l food sources located at the same distance and d i r e c t i o n f r o m the hive but at two dif f e r e n t heights ( « , A = on ground, and A , o = 170 c m high) when distance is gradually i n c r e a s e d . 57 to a m o r e distant; goal were seen f l y i n g as close as 50 c m above the high source, without paying any attention to it. On the other hand, as both food sources began to d r y out, 'Low' f o r a g e r s started to investigate the 'High' food source, while the 'High' f o r a g e r s began to pay attention to the 'Low' dish. Bees that switched f r o m a low to a high source did not find it by d e l i b e r a t e l y s p i r a l l i n g up the ladder on which the high source was placed, but by s p i r a l l i n g upward to set their c o u r s e f o r home and a c c i d e n t a l l y blundering into the new source. F i r s t r e c r u i t s appeared in a matter of minutes. R e c r u i t s to the high feeding site were accurate to within 40 c m on the low side and l e s s than 30 c m on the high side. T h e y did not overshoot the distance by m o r e than 30 cm, and their d i r e c t i o n a l e r r o r was not m o r e than 50 cm. However, the d i r e c t i o n a l e r r o r was much m o r e frequent than the e r r o r in distance. R e c r u i t s took a position check upon a r r i v a l and an o r i e n t a t i o n check when departing, whereas a scout took an orientation check upon departure and a p o s i t i o n check when i t returned. 59 DISCUSSION 1. C o l o u r attractiveness of food source: V i s u a l a t t r a c t i v e n e s s of the food s o u r c e plays an important r o l e in the speed with which an approaching f o r a g e r locates the food. C o n t r o l experiments in Section 4 c l e a r l y indicate that a feeding d i s h concealed by leaves was located m o r e slowly than a coloured d i s h . D i s h e s with c o n t r a s t i n g c o l o u r s were i n i t i a l l y m o r e a t t r a c t i v e than single c o l o u r s , r e c e i v i n g the f i r s t v i s i t s by the scouts ( F i g u r e la) and .i greater number of r e c r u i t s . S i m i l a r observations have been rep o r t e d by Butler, (1951), F r e e (1970), M e n z e l (1967), and L i n d a u e r (1970) and would apply h e r e where the scouts a r e concerned. R e c r u i t s however may have been attracted to these dishes m o r e by the p r e s e n c e of other bees than by colour arrangement. F i g u r e s l a and lb show that dishes with the highest a t t r a c t i o n to scouts did not always r e c e i v e the highest number of r e c r u i t s , suggesting that another factor,, other than c o l o u r a t t r a c t i v e n e s s , was involved. R e d - c o l o u r e d d i s h was treated the same as b l a c k and brown dishes. The slight contrast of these three c o l o u r s against the g r a s s y background made the dishes at l e a s t v i s i b l e , though not v e r y a t t r a c t i v e to the bees, as can be seen f r o m the d i s c o v e r y times in T a b l e I. Ye l l o w r e c e i v e d the l a r g e s t number of r e c r u i t s in the second half of the total exposure t i m e ( F i g u r e l b ) . The p o s i t i o n of the yellow dish, in the centre of the a r r a y of seven dishes, may have cre a t e d a r e i n f o r c i n g effect by the greater ac t i v i t y , a t t r a c t i n g m o r e bees to the c e n t r e / Since a l l seven dishes were only 30 c m apart f r o m each other, it would be quite easy for bees to switch f r o m one d i s h to another when they sensed m o r e a c t i v i t y . On the other hand, although bees may have i n i t i a l l y shown . p r e f e r e n c e f o r a colour arrangement, as soon as sugar solution was exhausted in the dishes with greatest v i s u a l a t t r a c t i v e n e s s , they did not hesitate to move and investigate dishes with l e s s a t t r a c t i v e colour arrangements ( F i g u r e l b ) . The f i r s t scouts and r e c r u i t s to a r r i v e at the two feeding dishes may a l s o have t h r u s t out t h e i r Nasanoff gland, thus m a r k i n g an abundant food s o u r c e f o r the others (Kalmus, 1954) . When the sugar solution was taken up, there would be no m o r e m a r k i n g until new scouts d i s c o v e r e d that the l e s s a t t r a c t i v e dishes had ample supplies of food. T h e i r scent could then at t r a c t new f o r a g e r s , being stronger than the d i s s i p a t i n g scent given off 15 minutes e a r l i e r . The r e s u l t s d i s c u s s e d above indicate that the p r e s e n c e of a colour contr.ast and/or an. a t t r a c t i v e colour at the food s o u r c e is v e r y important i n i t i a l l y , a t t r a c t i n g f i r s t bees to the food s o u r c e . However, once the s o u r c e is d i s c o v e r e d and found s a t i s f a c t o r y by the scouts, the r e c r u i t s land at the a d v e r t i s e d feeding d i s h by r e a c t i n g to the p r e s e n c e of other bees there, t h e i r body odour, and/or the product of t h e i r Nasanoff gland. 61 2. A t t r a c t i v e n e s s of scent: Scents such as orange, peppermint and cinnamon that were r e a d i l y accepted, attracted three groups of f o r a g e r s that concentrated on these p a r t i c u l a r scents. . P a r t i a l i t y could l a s t f o r s e v e r a l days, and only a few bees were seen to switch q u i c k l y f r o m one scent to another or to come to both scents in the c o u r s e of a few v i s i t s . T h i s constancy has a l s o been noted by E s c h (1976). Apparently, a single experience with a scent, if rewarded by sugar solution, produces 90%constanc y to that odour in subsequent ch o i c e experiments (Menzel and E r b e r , 1972). L e a r n i n g of a second o l f a c t o r y cue is not followed by extinction of the p r e v i o u s l y l e a r n e d stimulus (Wenner, 1971) and thus allows the above-mentioned 'hetero' f o r a g e r s to r e a c t to m o r e than one scent. Honey was not as s t i m u l a t i n g as the above f l o r a l scents. T h i s could be explained by the fact that most cf these N experiments were c a r r i e d out in the f i r s t half of the season, before t h e r e was any d e a r t h of nectar and well before the bees began to p r e p a r e for winter. In the f a l l , a l m o s t any sweet solution was taken up eagerly, and robbing of other hives became common. A n i s e seed o i l was avoided in the summer. In the f a l l , when there was a dearth of n a t u r a l food because of a lengthy p e r i o d of wet, cold weather, the scented sugar solution was taken up by two scouts, but no r e c r u i t came. On another occasion, after a s e r i e s of experiments, a food s o u r c e containing anise seed o i l was p l a c e d four m e t e r s f r o m two dishes that had been p r e v i o u s l y used but were now empty. S e v e r a l bees were p e r i o d i c a l l y checking the two old dishes and some of them were v i s u a l l y attracted to the a n i s e - s c e n t e d d i s h . However, none of them sat down to take up food; a l l nine bees that hovered above the d i s h during the 80-minute p e r i o d lef t f o r the hive without landing at the anise s o u r c e . It became quite obvious that bees a r e attracted to a food s o u r c e by its appearance, but that they do not take up sugar solution that contains a r e p u l s i v e scent, even when there is a s c a r c i t y of food around. The f o r a g i n g behaviour observed above; i . e., hover ing over the food source fo r as long as one minute before landing and taking up food strongly suggests that it may cost the bee l e s s energy to hover than to land and take off again. 3. Sugar l e v e l and recruitment: Section 3 s t r e s s e s the importance of sugar concentration f o r r e c r u i t m e n t . E v e n an o l f a c t o r i l y and v i s u a l l y a t t r a c t i v e d i s h w i l l be checked f u r t h e r f o r its sugar contents. If the sugar l e v e l is low, there w i l l be no r e c r u i t m e n t and, in the m a j o r i t y of cases, the scout w i l l not r e t u r n . It would seem, then, that an u n s a t i s f a c t o r y sugar l e v e l prevents the scouts f r o m dancing in the hive.and hence f r o m r e c r u i t i n g any new f o r a g e r s . The t h r e s h o l d of perception; i.e., the lowest concentration n e c e s s a r y to stimulate any sense of taste in hungry bees is 1-2% sugar solution. When many plants a r e in bloom, the t h r e s h o l d of acceptance is 4 0 % sugar, but in the f a l l , when there is s c a r c e l y any food, a 5 % solution w i l l s u f f i c e (von F r i s c h , 1971) . T h i s seasonal v a r i a t i o n may explain the l i t t l e or no r e c r u i t m e n t observed at the dishes with 1/16-molar concentration in T a b l e s III and IVb. 63 It should be pointed out that the honey bee's p e r c e p t i o n of sweetness is m o r e acute than man's; out of 34 sugar and s u g a r - l i k e substances tested, only nine were sweet to bees (von F r i s c h , 1950). C o n s i d e r i n g the number of flights a bee has to make to gather nectar f o r one g r a m of honey, we may well a p p r e c i a t e the need f o r this keenness of p e r c e p t i o n . Without it, too.much-time.and energy would be wasted in gathering-nectar r •from poorer sources, thus a d v e r s e l y affecting f o r a g i n g s u c c e s s . The p r e s e n c e of sugar syrup stimulated f u r t h e r v i s i t s . A s soon as a food s o u r c e d r i e d up, however, f o r a g e r s and r e c r u i t s did not remain, but went to distant, better sources, p e r i o d i c a l l y checking the o r i g i n a l s o u r c e . T h i s behaviour was thoroughly exploited during the t r a i n i n g s e s s i o n : when four 'flowers', a l l with concentrated sugar solution, were a r r a n g e d in a straight l i n e (Plate II), and the flower c l o s e s t to the hive was not r e f i l l e d , bees alighted on it, probed f o r food, and moved to the next flower in l i n e . The distance between the fl o w e r s was gradually i n c r e a s e d to t r a i n the .bees to s e a r c h f a r t h e r . I n i t i a l l y , the s e p a r a t i o n should not be l a r g e r than 0.5 meter, in o r d e r to obtain the f a s t e s t response. 4. O l f a c t o r y v s . v i s u a l a t t r a c t i v e n e s s : Section 1 in the R e s u l t s shows that colour or colour contrast played an important r o l e in a t t r a c t i n g bees to the food s o u r c e . However, a bee w i l l not land and take up food unless the c o r r e c t scent is p r e s e n t (Section 2). A d d i n g an a t t r a c t i v e scent f u r t h e r reduces the d i s c o v e r y 64 t i m e (Section 3b) . . In the experimental part of Section 4a, the v i s u a l l y a t t r a c t i v e d i s h was d i s c o v e r e d most qui c k l y even when it was competing with two f r e s h l y - s c e n t e d food s o u r c e s . However, this reduced d i s c o v e r y t i m e can be explained by the fact that the o r i g i n a l C o n t r o l scouts were used to the l o c a t i o n and colour arrangement of this d i s h and r e a c t e d to it f i r s t . When scent was added to v i s u a l l y non-attractive dishes, the :group f o r a g -ing on a v i s u a l l y a t t r a c t i v e d i s h sp l i t up and t r a n s f e r r e d to scented dishes ( F i g u r e 4a, E x p e r i m e n t ) . P r o b a b l y the p u r p l e d i s h (F]_) then r e c e i v e d fewer r e c r u i t s because scouts and f o r a g e r s f r o m F-, and F g not only were b r i n g i n g a strong sugar solution back to the hive, but a l s o an a t t r a c t i v e sc ent, so that t h e i r m o r e vigorous dancing r e c r u i t e d bees that looked f o r that F2-F3 scent when they reached the feeding s i t e . In Section 4b (Control), a s t r o n g s o l u t i o n was found by the bees, but v e r y l i t t l e r e c r u i t m e n t to it o c c u r r e d . . A p a r t i a l explanation is that r e c r u i t m e n t i n c r e a s e s 15-30 minutes after the i n i t i a l exposure of the food s o u r c e ( F i g u r e 7a). D u r i n g the experiments r e p o r t e d in Section 4b, the food s o u r c e was observed for only 15 minutes, whereas in the sugar experiments (Section 3), the total exposure t i m e was 30 minutes. Many bees do not f l y out to the food s o u r c e immediately after the f i r s t dance, but wait in the hive until s e v e r a l scouts r e p o r t . . A s the number of dancers a d v e r t i s i n g the s o u r c e i n c r e a s e s , so w i l l r e c r u i t m e n t subsequently i n c r e a s e ( E s c h and Bastian, 1970). Sometimes the f i r s t r e c r u i t s a r r i v e d b e f o re the scout returned to the feeding dish. T h i s would suggest (see a a l s o Ribbands, 1949) that a group of f o r a g e r s was f a m i l i a r with a scent used in previous experiments and flew out to the old site as soon as the f i r s t s u c c e s s f u l scout brought that scent with her to the hive. Although the importance of scent in a t t r a c t i n g honey bees to a food s o u r c e is s t r e s s e d throughout the l i t e r a t u r e (Lindauer, 1971; K r i s t o n , 1973), colour seems to be just as, if not more, important. M y bees were v e r y e a s i l y conditioned to yellow, and paid numerous v i s i t s to a yellow c h a i r as soon as it was brought outside. B u t l e r (1951) observed that a yellow-c o l o u r e d c o v e r s l i p without scent was s i g n i f i c a n t l y m o r e a t t r a c t i v e than a p l a i n c o v e r s l i p with a scent that was n o r m a l l y a t t r a c t i v e to the bees. It can be concluded that colour is v e r y important in a t t r a c t i n g a bee to the food source, once the bee has reached the v i c i n i t y of the feeding s i t e . T he bee w i l l swerve towards a v i s u a l l y a t t r a c t i v e food s o u r c e near the l o c a t i o n indicated by the scout, hover above it, leave, check another s o u r c e nearby, return, hover agaiin, and if the scent she p e r c e i v e s is not re p u l s i v e , she w i l l land and investigate. T h e r e is a b u i l t - i n bias i n experimental work of the kind d e s c r i b e d here, because bees t r a i n e d to take up sugar solution f r o m feeding dishes a r e perhaps m o r e l i k e l y to exhibit the 'land/investigate/take up food 1 behaviour than wholly untrained f o r a g e r s might be. In the l a t t e r case, the p r e s e n c e of a t t r a c t i v e scent in addition to colour is m o r e l i k e l y to be mandatory df those f o r a g e r s a r e to take up sugar solution. 66 5. . U s e of landmarks and p o l a r i z e d light: Bees take d i m e n s i o n a l bearings on the l o c a t i o n of a food s o u r c e (Results; Section 5). In the absence of p o l a r i z e d sky-light, t h e i r path to a low s o u r c e exploits landmarked obstacles to f a c i l i t a t e navigation. In the p r e s e n c e of p o l a r i z e d light, the bees could f l y d i r e c t l y between the hive and the s o u r c e over the top of such obstacles. Because bees p r e f e r e n t i a l l y use p o l a r i z e d light even f o r short distances (Wellington, 1974), it is evident that even l a n d m a r k i n g bees w i l l use p o l a r i z e d l i g h t to straighten t h e i r c o u r s e when the p o l a r i z e d s k y - l i g h t is the r e . Interestingly, the number of bees f o r a g i n g f r o m the hive i n c r e a s e d noticeably whenever p o l a r i z e d light returned, as when an o v e r c a s t broke. P e r h a p s some bees a r e not good l a n d m a r k e r s , and consequently cannot work when there is no p o l a r i z e d l i g h t . F r o m the a c t i v i t y around an o b s e r v e r standing near a food s o u r c e placed at head height, it is obvious that bees can be confused by a landmark too c l o s e to the site of t h e i r food. A r e c r u i t that knows the d i r e c t i o n , distance and height she has to f l y switches f r o m c e l e s t i a l compass to l a n d m a r k i n g when she a r r i v e s in the v i c i n i t y of the food s o u r c e . L i n d a u e r (1976) showed that when a v i s u a l m a r k e r was added near a food s o u r c e which p r e v i o u s l y had no landmark near it, f i n a l orientation improved immediately. 6. F o r a g i n g and s e a r c h i n g behaviour after r e l o c a t i o n of food s o u r c e to  sunlit and shadowed areas: Section 6 demonstrates honey bees' r e l u c t a n c e to forage in dark, shadowy ar e a s when b r i g h t e r a r e a s a r e a v a i l a b l e . In shaded areas f o r a g e r s a r e l e s s able to use t h e i r colour v i s i o n to locate a flower, its petal patterns or its nectar guides. T h e r e was a co n s i s t e n t l y higher number of scouts at the boundary than in other locations (Table V; Figure©), at l e a s t when the food s o u r c e was i n i t i a l l y p laced on the d a r k / l i g h t boundary. T h i s concentration was probably because the boundary zone had been used e a r l i e r f o r other experiments so that some scouts continually checked i t . F o l l o w i n g re l o c a t i o n , the higher number of scouts than r e c r u i t s at the new sites would r e s u l t f r o m most of the o r i g i n a l s c o u t / r e c r u i t population on the boundary becoming new scouts in the d a r k and light a r e a s . A s in Section 7, the s m a l l number of r e c r u i t s observed during the f i r s t 15-minute exposure t i m e could be explained by the slow i n i t i a l rate of r e c r u i t m e n t . T h e r e was, however, a c l e a r d i s t i n c t i o n between the high numbers of scouts and r e c r u i t s that a r r i v e d at the d i s h in 'light' and the low numbers that v i s i t e d the d i s h in 'dark' ( F i g u r e 4a). In fact, the d i s h in the shade was s c a r c e l y v i s i t e d . Under natural conditions, the bee that came to the shstded d i s h frequently did so a c c i d e n t a l l y while s e a r c h i n g for the old food s o u r c e . In such instances, the bee came c l o s e enough to s m e l l or even see the food s o u r c e while making one of the loops that f o r m p a r t of the s e a r c h i n g behaviour near a rep o r t e d food s i t e . O c c a s i o n a l l y , the shaded a r e a was entered p u r p o s e f u l l y by scouts and l a t e r by r e c r u i t s that came d i r e c t l y f r o m the hive and c r o s s e d the d i v i d i n g line.without hesitating. A f t e r l o c a t i n g the food, these bees returned to it in the shade without f l y i n g back v i a 68 the sunlit route. The branches of the catalpa tree did not form a solid cover, however, so that such bees would be able to see polarized light overhead. Bees trained to come to yellow paper also investigated anything that resembled it on the shaded site of the boundary. In one experiment, for example, four bees quickly investigated the dish when shifting shadow pattern produced sun flecks near it on the grass. On cloudy days, when there was no difference in illumination between the locations of two identical food sources, 'boundary', 'light', and 'dark' were indistinguishaBle. The longer discovery times on the boundary (Table Vb; Figure 6b) then simply iindicate that the bees required more time to locate the food source at the beginning of an experiment than they needed to find the relocated source. The numbers of scouts and recruits were lower for 'dark' and 'light' than for the boundary dish in these experiments mainly because the group at the boundary dish split up to visit the two new sites. Under sunny conditions, when two dishes were relocated in shaded and sunlit areas, bees that came to the 'boundary' site searched in both directions, describing circles and semicircles across the dividing line. Most of them would not go very far into the shade. On cloudy days, when there was no boundary the bees flew in semicircles about one meter in diameter in both directions from the old feeding site and did not hesitate to approach the 'dark' food source. F o r the f i r s t 15 minutes after finding it, they continued to approach it via the old site; after that, they came and went directly between the hive and the dish. 69 7. F o o d r e l o c a t i o n and s e a r c h i n g behaviour: T h e s e a r c h i n g behaviour d e s c r i b e d above f o r a cloudy day applies to a l l r e l o c a t i o n s of feeding dishes, even on sunny days, as long as they were not in shadow. . E c k e r t (1955) observed that honey bees, on l e a v i n g the feeding si t e s , f requently c i r c l e d d a few times over the place, "as if to f i x the landmarks in t h e i r m e m o r y or to get t h e i r b e a r i n g f o r the r e t u r n t r i p , b e f o r e s t a r t i n g f o r home. " It was int e r e s t i n g to observe that the number of c i r c l e s and s e m i c i r c l e s d e c r e a s e d with each subsequent v i s i t , u s ually s t a r t i n g with f i v e on the f i r s t t r i p , then three on the second, and f i n a l l y r e d u c i n g to one quick sweeping t u r n towards the hive at the end of the t h i r d v i s i t . 8 . Indication of height: The confusion of some r e c r u i t s who a r r i v e d to a food s o u r c e at head height when an o b s e r v e r was standing near-by (described in Section 5) does not only demonstrate that landmarks placed in the v i c i n i t y of a food s o u r c e a r e thoroughly investigated; it a l s o poses a v e r y i n t e r e s t i n g question as to how did the r e c r u i t s know that the food was standing on something the height of the observer's head. The only study f a i n t l y r e l a t e d to height indicates that honey bees show a p r e f e r e n c e f o r plants of the same height within a given species, p o l l i n a t i n g plants of the same stature m o r e frequently than plants of different height (Faulkner, 1976). However, this is only a d i f f e r e n c e of a few inches; so f a r , nobody has paid any attention to honey bee populations 70 f r o m the same hive and f o r a g i n g at two d i s t i n c t i v e heights, e.g., on the ground and in the t r e e s . Although von F r i s c h e j ^ a l ^ (1953) concluded that bees did not communicate i n f o r m a t i o n on the height of a food source, the data obtained i n the summer and f a l l of 197 6 and presented in T a b l e s VII a n . aTnd VIII show that scouts do communicate in f o r m a t i o n on height to t h e i r f o l l o w e r s . When two scouts independently and simultaneously d i s c o v e r separate sources, one 'high' and one 'low', that are located at the same distance and d i r e c t i o n f r o m the hive, two groups of r e c r u i t s q u i c k l y f o r m and r e m a i n constant to their r e s p e c t i v e sources. It was i n t e r e s t i n g to observe that, after a ladder with the 'high' and 'low' dishes was removed, the two pools of f o r a g e r s were maintained, one a r r i v i n g high, the other a r r i v i n g low to check the empty s i t e s . It seems that height, as w e l l as distance and di r e c t i o n , are p r e s s e t for the f l y i n g f o r a g e r ; bees f l y i n g to distant food sources did not pay any attention to food source on the ladder even though they flew only a few inches away f r o m it on their 'highway' f r o m the hive and over the house. The lower numbers of 'high' f o r a g e r s i n Table VIII and F i g u r e 8 were influenced by the low temperatures and high winds that p r e v a i l e d on the autumn day on which one of the 50-meter experiments was p e r f o r m e d . The wind c h i l l created a temperature that was b o r d e r l i n e f o r flight. Consequently, s e v e r a l 'high' f o r a g e r s were so cold that they f e l l to the ground just after taking off f r o m the high source, and were only able to complete their t r i p back to the hive after they had warmed up by buzzing on the ground (most in s e c t s need to generate and maintain a temperature of 24°C i n their flight m u s c l e s in order to f l y (Heinrich, 197 4)). The 'low' f o r a g e r s f l y i n g close to the ground were not so affected. 71 When the study is reported, the m e c h a n i s m f o r communicating height may be the subject of much speculation f o r some time, but I a m quite s u r e that it, as well as the means of distance communication, w i l l be eventually solved, since the dances as well as much of the physiology of the honey bee a r e b e i n g r e - i n v e s t i g a t e d . T h e r e a r e s e v e r a l p o s s i b i l i t i e s , but the fact that e r r o r s in reckoni n g distance and in height r e s e m b l e one another m o r e than they r e s e m b l e e r r o r s in d i r e c t i o n s t r o n g l y suggests the m e c h a n i s m combines height and distance, while keeping d i r e c t i o n separate. A t present, r e s e a r c h on honey bee communication is a c t i v e l y c o n s i d e r i n g sound, r a t h e r than 'dances' as a medium f o r communicating distance and if this p r o v e s true, then pulsed sound may well be the means f o r a l s o communicating height through the p r e s s u r e - s e n s i t i v e organs in the antennae. Sound product i o n i n c i d e n t a l l y is found in m o r e genera of the bee f a m i l y than is dancing behaviour. F u r t h e r m o r e , inside a dark hive, the eyes of potential r e c r u i t s that a r e following a dancer cannot function so that otii er means of communication, e s p e c i a l l y those combining t a c t i l e and aud i t o r y components, as through the antennae, must be highly important to the honey bee. 9. Dis t a n c e at.which d i r e c t i o n is indicated: In most of the experiments r e p o r t e d here, the distance between the food s o u r c e and the hive ranged f r o m 2. 5 to 10 m e t e r s . T h e r e is no doubt that both distance and d i r e c t i o n were t r a n s m i t t e d by a s u c c e s s f u l scout to her r e c r u i t s . R e c r u i t s c o n s i s t e n t l y a r r i v e d at a p p r o p r i a t e l y exposed sites l e s s than two minutes after the scout's departure, usually with highly a c c u r a t e distance reckoning, but with d i r e c t i o n a l e r r o r s of some +_ 30 cm. B o c h (1957) r e p o r t s that A p i s m e l l i f e r a l i g u s t i c a c a n begin to indicate d i r e c t i o n when the food s o u r c e is 8 meters or f u r t h e r away f r o m the hive. The observations r e p o r t e d here suggest that f o r a g e r s of the Italian honey bee indicate d i r e c t i o n as well as distance as c l o s e as 2.5 m e t e r s to the hive. On s e v e r a l occasions, dishes were placed 120° to the m a i n flight pathp 2-3 meters f r o m the hive, i n an a r e a not p r e v i o u s l y v i s i t e d by a f o r a g e r . Yet the behaviour on d i s c o v e r y , departure and r e c r u i t i n g was the same as d e s c r i b e d in Sections 1-7. It would be v e r y i n t e r e s t i n g to observe the dance pattern of these bees and see if it indeed does v a r y with changes in distance to the food s o u r c e . In conclusion, we should keep in mind that honey bees have a genetic p r e d i s p o s i t i o n to r e a c t to many s t i m u l i . L i v i n g conditions then f o r c e the individuals into a number of l e a r n i n g situations in which they become p r o g r a m m e d to d i s p l a y a p p r o p r i a t e r e s p o n s e s . It is p r o b a b l y i m p o s s i b l e to determine, once and for a l l , the dominance of one stimulus over another. T h e best one can expect is to learn.about the behaviour of a p a r t i c u l a r group of individuals under a p a r t i c u l a r set of conditions. Consequently, generalizations with r e s p e c t to honey bee behaviour made by von F r i s c h and his i n t e r p r e t e r s should be treated as such. The behaviour d e s c r i b e d h e r e could be best exploited to improve p o l l i n a t i o n p r a c t i c e s . Since hives a r e often moved into o r c h a r d s or 73 f i e l d s d uring the f l o w e r i n g of a crop, t r a i n i n g bees beforehand to a s s o c i a t e a r e w a r d with an odour at the height of the c r o p to be pollinated should r e s u l t in the bees s e l e c t i n g sites that contain the t r a i n i n g scent, thus l e a d i n g to a higher f r u i t y i e l d . With r e s p e c t to the r e s u l t s d e s c r i b e d in this t h e s i s , it would be pr o f i t a b l e to examine in greater d e t a i l honey bees' communication of di r e c t i o n , distance and height over short distances by using two or m o r e different r a c e s to obtain m o r e comparative i n f o r m a t i o n . T he great advantage of studying short-range, as opposed to long-range, f o r a g i n g is that one can observe the f o r a g e r at a l l times, even as she t r a v e l s between the hive and the food source, and thus determine a c c u r a t e l y the steps in her responses to the food, her fellows, and the sur r o u n d i n g environment. 74 S U M M A R Y The i n v e s t i g a t i o n s on short-range foraging behaviour of the honey bee, A p i s m e l l i f e r a l i g u s t i c a , reported in this study, have shown the following: 1. Despite many general and widely-accepted statements, the d i r e c t i o n of the food s o u r c e is indicated by scouts of the Italian honey bee, A . m. 1  ligustica, to t h e i r hive mates wihen the food s o u r c e is as c l o s e as 2.5 m e t e r s to the hive. 2. C o n t r a r y to the l i t e r a t u r e , the height of the food s o u r c e is communicated by the bees in addition to its distance and d i r e c t i o n . Two food sources at two different eheights generate two pools of f o r a g e r s , which r e m a i n constant to t h e i r r e s p e c t i v e heights even after the food sources have been removed, one a r r i v i n g high and the other low. 3. Bees take d i m e n s i o n a l bearings on the l o c a t i o n of the food source. In the absence of p o l a r i z e d sky-light, t h e i r path to a low s o u r c e exploits landmarked obstacles to f a c i l i t a t e navigation. In the p r e s e n c e of p o l a r i z e d light, the bees f l y d i r e c t l y between the hive and the s o u r c e over the top of such o b s t a c l e s . A r e c r u i t that knows the d i r e c t i o n , distance, and height she has to fly, switches f r o m c e l e s t i a l compass to l a n d m a r k i n g when she a r r i v e s in the v i c i n i t y of the food s o u r c e . 4. In addition to landmarks, the l o c a t i o n of the feeding d i s h in sun r a t h e r than in a shaded a r e a enhances its d i s c o v e r y . Under sunny conditions, dishes in the sun a r e investigated and v i s i t e d ; dishes in shadow a r e not. On cloudy days, when there is no d i f f e r e n c e in i l l u m i n a t i o n between the locations of two id e n t i c a l food sources, both feeding sites 75 a r e v i s i t e d with the same frequency. 5. Once in the general location, the p r e s e n c e of a co l o u r contrast and/or an at t r a c t i v e c o lour (e.g. yellow, purple) at the food s o u r c e is v e r y important i n i t i a l l y , a t t r a c t i n g f i r s t bees to the food s o u r c e . However, once the s o u r c e is d i s c o v e r e d and found s a t i s f a c t o r y by the scouts, the r e c r u i t s land at the feeding site by r e a c t i n g to the sight of other bees there, t h e i r body odour and/or the product of t h e i r Nasanoff gland. 6. Although honey bees a r e attracted to a food s o u r c e by its appearance, they do not take up sugar solution that contains a r e p u l s i v e scent. E v e n when the food is s c a r c e , bees w i l l hover above a v i s u a l l y a t t r a c t i v e , but olfactorily r e p u l s i v e s o u r c e and eventually l e a v e without having landed at a l l . If they land and probe the food with t h e i r p r o b o s c i s , they do not r e c r u i t other bees to this s i t e . On the other hand, when the sugar solution is scented with a t t r a c t i v e scent such as orange, peppermint, or cinnamon, 'landing/take-up food^behaviour takes p l a c e a f t e r a v e r y b r i e f p e r i o d of h o v e r i n g and f i r s t r e c r u i t s a r r i v e s h o r t l y . 7. E v e n an o l f a c t o r i l y and v i s u a l l y a t t r a c t i v e d i s h w i l l be v i s i t e d by r e c r u i t s only if its sugar content is found s a t i s f a c t o r y by its d i s c o v e r e r . A s soon as one food s o u r c e is allowed to d r y up, scouts and r e c r u i t s move to distant, better sources, p e r i o d i c a l l y checking the o r i g i n a l s o u r c e . 8. When the food s o u r c e is moved f r o m one l o c a t i o n to another, bees s e a r c h until the new l o c a t i o n is found. The new l o c a t i o n is found by a r r i v i n g at old location, c i r c l i n g there, and then moving in the right or 76 wrong d i r e c t i o n along the a r c of the distance at which the o r i g i n a l s o u r c e was located f r o m the hive. A s they f l y along this a r c , they either z i g - z a g or c i r c l e every few seconds, s e a r c h i n g f o r the new s i t e . Once the new sou r c e is found, the bees continue to a r r i v e v i a the old l o c a t i o n f o r nearly. 30 minutes. L a t e r , they approach the feeding site d i r e c t l y f r o m the hive. When leaving, a new food l o c a t i o n after t h e i r f i r s t v i s i t , bees hover over it, c i r c l e around and s p i r a l up in a definite pattern ( i . e . get the i r bearing), r r e d u c i n g the number of c i r c l e s and s e m i c i r c l e s f r o m f i v e to three and f i n a l l y to one quick sweeping t u r n towards the hive at theiend of t h e i r t h i r d v i s i t . L a t e r they f l y d i r e c t l y back to hive. It is concluded that the Italian honey bees locate the food with much greater a c c u r a c y than is c u r r e n t l y b e l i e v e d . 77 L I T E R A T U R E C I T E D Anderson, A. 1972. The abil i t y of honey bees to generalize v i s u a l s t i m u l i . In_: Wehner, R. (ed. ) 1972. Information p r o c e s s i n g in the v i s u a l systems of arthropods. S p r i n g e r - V e r l a g , New York. 334 pp. Bisetzky, A. R. 1957. Die Tanze der Bienen nach einem F u s s w e g zum Fu t t e r p l a t z . Z. v g l . P h y s i o l . 40: 264-288. Boch, R. 1957. R a s s e n m a s s i g e Unterschiede b e i den Tanzen der Honigbiene (Apis m e l l i f e r a L. ) Z. v g l . P h y s i o l . 40: 289-320. Brehm, B. G. and D. K r e l l . 1976. F l a v o n o i d l o c a l i z a t i o n in e p i d e r m a l pa p i l l a e of flower petals: A s p e c i a l i z e d adaptation f o r u l t r a v i o l e t absorption. Science 190: 1221-1223. Butler, C.G. 1951. The importance of perfume in the d i s c o v e r y of food by the w orker honeybee (Apis m e l l i f e r a L. ). P r o c . R. Soc. Lond. B. B i o l . S c i . 138: 403-413. Butler, C.G. 1971. The world of the honey bee. C o l l i n s , London. 185 pp. Daumer, K. 1958. , Blumenfarten, wie sie die Bienen sehen. Z. v g l . P h y s i o l . 41: 49-110. Dhaliwal, H.S. and P . L . Sharma. 1974. F o r a g i n g range of the Indian honey bee. J. Ap i c . Res. 13: 137-141. E c k e r t , J . E . 1955. The fl i g h t of the honey bee. Am. Bee J. 95:.395-401. E i b l - E i b e s f e l d t , I. 1970. Eth o l o g y - the biology of behaviour. Holt, Rinehart and Winston, Inc. 529 pp. E s c h , H. 1967. The evolution of bee language. S c i . Am. 216: 97-104. E s c h , H. 1976. F o r a g i n g strategies in bees. Am.' Bee J. 116: 568-573. E s c h , H. and J.A. Bastian. 1970. How do newly r e c r u i t e d honeybees approach a food site. Z. v g l . P h y s i o l . 68: 175-181. E s c h , H.,I. E s c h , andW.E. K e r r . 1965. Sound: an element common to communication of stingless bees and to dances of the honey bee. Science 14: 320-321. F a u l k n e r , G.J. 1976. Honey bee]:behaviour as affected by plant height and flower colour i n b r u s s e l sprouts. J. A p i c . R es. 15: 15-18. 78 F r e e , J. B. 1969. Influence of the odour of a honey bee colony's food stores on the behaviour of its f o r a g e r s . Nature 222: 278. F r e e , J. B. 1970. E f f e c t of f l o w e r shapes and nectar guides on the behaviour of f o r a g i n g honey bees. Behaviour 37: 269-285. F r i s c h , K. von. 1914/1915. D e r F a r b e n s i n n und F o r m e r i s i n n der Bienen. Z o o l . Jb. ( P h y s i o l . ) 35: 1-188. F r i s c h , K. von. 1919. Ueber den G e r u c h s i n n der Bienen. Z o o l . Jb. ( P h y s i o l . ) 37* 1-228. F r i s c h , K. von. 1923. Uber die Sprache der Bienen. Z o o l . Jb. ( P h y s i o l . ) 40: 1-186. F r i s c h , K. von. 1946. Die Tanze der Bienen. O s t e r r . Z o o l . Z. 1: 1-48. F r i s c h , K. von. 1947. The dances of the honey bee. B u l l . Anim. Beh. 5: 3-32. F r i s c h , K. von. 1950. Bees. T h e i r v i s i o n , c h e m i c a l senses, and language. C o r n e l l Univ. P r e s s , Ithaca. 118 pp. F r i s c h , K. von. 1951. O r r e n t i e r u n g s v e r m o g e n und Sprache der Bienen. Naturwissenschaften 38: 105-112. F r i s c h , K. von. 1965. T a n z s p r a c h e undeOrientierung der Bienen. S p r i n g e r - V e r l a g , B e r l i n . 578 pp. F r i s c h , K. von. 1967a. The dance, language and or i e n t a t i o n of bees. The Belknap P r e s s of H a r v a r d U n i v e r s i t y P r e s s , Cambridge, M a s s . 566 pp. F r i s c h , K. von. 1967b. Honeybees: do they use d i r e c t i o n and distance i n f o r m a t i o n provided by their dances? Science 158: 1072-1076. F r i s c h , K. von. 1968. The role of dances in r e c r u i t i n g bees to f a m i l i a r sites. Anim. Behav. 16: 531-533. F r i s c h , K. von. 1971. Bees: t h e i r v i s i o n , c h e m i c a l senses and language. Rev. Jed. C o r n e l l Univ. P r e s s , Ithaca and London. 157 pp. F r i s c h , K. von. 1974. Decoding the language of the bee. Science 185: 663-668. 79 F r i s c h , K. von, H. H a r a n and M. L i n d a u e r . 1953. Gibt es in der Sprache der Bienen eine Weisung nach oben und unten? Z. v g l . P h y s i o l . 35: 219-245. Gary, N. E . 1975. A c t i v i t i e s and behaviour of honey bees. In: The hive and honey bee, rev. ed. Dadant and Sons (eds. ) Dadant and Sons Inc. Hamilton, 111. 740 pp. Gary, N. E. and P . L . W i t h e r e l l . 1971. A method f o r t r a i n i n g honey bees to forage at feeding stations. Ann. Entomol. Soc. Am. 64: 448. Gould, J . L . 1974. H o n e y b e e communication. Nature 252: 300-3011 Gould, J . L . 1975a. Honey bee recruitment: The dance-language c o n t r o v e r s y . Science 189: 685-693. Gould, J. L. 1975b. Communication of distance information by honey bees. J. Comp. P h y s i o l . A. 104: 161-173. Gould, J. L. 1976. The dance language c o n t r o v e r s y . Q. Rev. B i o l . 51: 211-244. Gould, J. L. , M. Henerey, a n d M . C . M a c L e o d . 1970. Communication of d i r e c t i o n by the honey bee. Science 169: 544-554. Guldberg, L.D. a n d P . R . Atsatt. 1975. F r e q u e n c y of r e f l e c t i o n and absorption of u l t r a v i o l e t light in f l o w e r i n g plants. Am. M i d i . Nat. 93: 35. Hein, G. 1950. Uber richtungsweisende Bienentanze bei F u t t e r p l a t z e n in Stocknahe. Experimented: 6: 142-144. H e i n r i c h , B. 1974. T h e r m o r e g u l a t i o n in endothermic insects. Science 185: 747-756. Heran, H. 1959. Wahrnehmung und Regelung den Flugeigengeschwindigkeit bei Apis m e l l i f i c a . Z. v g l . P h y s i o l . 42: 102-163. Hoefer, I. and M. L i n d a u e r . 1975. The l e a r n i n g behaviour of two races of Apis m e l l i f e r a under modified orientation conditions. J. Comp. P h y s i o l . 99: 119-138. H o r r i d g e , G.A. (ed. ) 1975. The compound eye and v i s i o n of i n s e c t s . C l a r e n d o n P res s, Oxford. 595 pp. 80 Jay, C.S. 1969. The p r o b l e m of d r i f t i n g i n c o m m e r c i a l a p i a r i e s . Am. Bee J. 109: 178-179. Johnson, D.L. 1967. Honey bees: do they use the d i r e c t i o n i n f o r m a t i o n contained in their dance maneuver? Science 155: 844-847. Johnson, D.L. and A.M. Wenner. 1970. R e c r u i t m e n t e f f i c i e n c y in honey bees: studies on the role of olfaction. J. Apic. Res. 9: 13-18. Jones, C. E . a n d S . L . Buchman. 1974. U l t r a v i o l e t f l o r a l patterns as functional orientation cues in hymenopterous po l l i n a t i o n systems. Anim. Behav. 22: 481-485. Kalmus, H. 1954. The c l u s t e r i n g of honey bees at a food source. B r i t . J. Anim. Behav. 2: 63-77. Kevan, P. G. 1972. F l o r a l c o l o r s in the high a r c t i c with r e f e r e n c e to in s e c t - f l o w e r r e l a t i o n s and pollination. Can. J. Bot. 50: 2289-2316. Koltermann, R. 1974. P e r i o d i c i t y in the ac t i v i t y and l e a r n i n g p e r f o r m a n c e of the honey bee. In: Barton L. Browne (ed. ) 1974. E x p e r i m e n t a l an a l y s i s of insect behaviour. S p r i n g e r - V e r l a g , New York. 366 pp. K r i s t o n , I. 1973. E v a l u a t i o n by Api s m e l l i f e r a of odour and c o l o u r signals as aids to or i e n t a t i o n at the feeding site. J. Comp P h y s i o l . 84: 77-94. Lindauer, M. 1953. D i v i s i o n of labour in the honey bee colony. Bee , W o r l d 34: 63-73; 85-90. Lindauer, M. 1971a. The functional significance of the honey bee waggle dance. Am. N a t u r a l i s t 105: 87-96. Lindauer, M. 1971b. Communication among s o c i a l bees. H a r v a r d Univ. P r e s s , Cambridge, M a s s . 161 pp. Lindauer, M. 1975. The effective i n f o r m a t i o n contents of the dance of the honey bee. In£ Schoene. H. (ed. ). F o r t s c h r i t t e der Zoologie, V o l . 23: 31-33. 1. M e c h a n i s m s of sp a t i a l p e r c e p t i o n and orientation as related to gravity. International Symposium, Koeln, West Germany, 18-20 Sept. 1973. x i i + 296 pp. Gustav F i s h e r V e r l a g , Stuttgart. 81 Lindauer, M. 1976. F o r a g i n g and homing flight of the honey bee, some general p r o b l e m s of orientation. In: Rainey, R.C. 1976. , Insect flight. Symposia of the Royal Ent. Soc. London: No. 7. Black-well S c i e n t i f i c P u b l i c a t i o n s , Oxford. Lindauer, M. and W. E . K e r r . I960. Communication between the workers of stingless bees. Bee W o r l d 41: 29-41, 65-70. Mazokhin-Porshnyakov, G. H. 1969. Insect v i s ion. P l e n u m P r e s s , New York. 306 pp. Men z e l , R. 1967. Das Gedachtnis der Honigbiene fur Spektralfarben. Z. v g l . P h y s i o l . 56: 22-62. Me n z e l , R. and J. E r b e r . 1972. The influence of the quantity of reward on the l e a r n i n g p e r f o r m a n c e in honey bees. Behaviour 41: 27-42. Mi c h e n e r , C.D. 1974. The s o c i a l behaviour of the bees. The Belknap P r e s s of H a r v a r d U n i v e r s i t y P r e s s , Cambridge, M a s s . 404 pp. M o r s e , G.D. 1972. How about honey bees: are they the only captives of inst-inct? Glean. Bee Cult. 100: 10-12. New, D. A. T. and J. K. New . 1971. The dances of honey bees at s m a l l zenith distances of the sun. J. Exp. B i o l . 39: 271-291. Oettingen-Spielberg, T. 1949. Uber das Wesen der Suchbiene. Z. v g l . P h y s i o l . 31: 454-489. P r o c t o r , M. C. and P. Yeo. 1972. The pol l i n a t i o n of f l o w e r s . T a p l i n g e r , New York. 418 pp. Renner, M. 1959. Uber ein weiteres V e r s e t a u n g s e x p e r i m e n t zur Analyse des Ze i t s i n n e s und der Sonnenorientierung der Honigbiene. Z. v g l . P h y s i o l . 42: 449-483. Ribbands, C.R. 1949. The fo r a g i n g methods of ind i v i d u a l honeybees. J. Anim. E c o l . 18: 47-66. Ribbands, C.R. 1955. The scent perception of the honeybee. P r o c . R. Soc. London B. B i o l . S c i . 143: 367-379. Romoser, W.S. 1973. The science of entomology. Mac M i l l a n , New York, 449 pp. Segui-Goncalves, L. 1969. A study of orientation information given by one t r a i n e d bee dancing. J. A p i c . Res. 8: 113-132. 82 Spangler, H. G. 1974. F l u o r e s c e n t ink f o r m a r k i n g honey bees. Am. Bee J. 114: 168. Thorp, R.W. , D.L. B r i g g s , J.R. E s t e s and E.H. E r i c k s o n n . 1975. N e c t a r f l u o r e s c e n c e under u l t r a v i o l e t i r r a d i a t i o n . Science 189: 476-478. Ts c h u m i , P. 1950. Uber der verbetanz der Bienen beinnahen T r a c h t g u e l l e n . Sctrweiz. Bienenztg. 73: 129-134. T u r e l l , M. J. 1976. Honey bee communication, P a r t I. Am, Bee J. 116: 17-20. Wehner, R. 1976. P o l a r i z e d - l i g h t navigation by i n s e c t s . S c i . Am. 235: 106-115. Wellington, W. G. 1955. S o l a r heat and plane p o l a r i z e d light v e r s u s the light compass r e a c t i o n in the orientation of insects on the ground. Ann. E n t o m o l . Soc. Am. 48: 67-76. Wellington, W. G. 1974. A s p e c i a l l i g h t to s t e e r by . Nat. H i s t . 83: 46-52. Wells, P.H. and A.M. Wenner, 1971. The influence of food scent on behaviour of f o r a g i n g honey bees. P h y s i o l . Z o o l . 44: 191-209. Wenner, A.M. 1962. Sound production during the waggle dance of the h o n e y b e e . Anim. Behav. 10: 79-95. Wenner, A.M. 1964. Sound communication in honey bees. S c i . Am. 210: 116-124. Wenner, A.M. 1967. Honey bees: do they use the distance information contained in t h e i r dance maneuver? Science 155: 847-849. Wenner, A.M. 1971. The bee language c o n t r o v e r s y - an experience in science. Boulder, Colorado, USA, E d u c a t i o n a l P r o g r a m s Improvement C o r p . 109 pp. Wenner, A.M. and D.L. Johnson. 1967. Honeybees: do they use d i r e c t i o n and distance i n f o r m a t i o n p r o v i d e d by t h e i r dances? Science 158: 1076-1077. Wenner, A.M., P.H. Wells, and F. J. Rohlf. 1967. An analysis of the waggle dance and r e c r u i t m e n t in honey bees. P h y s i o l . Z o o l . 40: 317-344. 83 Wenner, A.M., P.H. Wells, and D. L, Johnson. 1969. H o n e y b e e r e c r u i t m e n t to food s o u r c e s : olfaction or language? Science 164: 84-86. Wilson, E . O. 1971. The i n s e c t s o c i e t i e s . H a r v a r d Univ. P r e s s , Cambridge, M a s s . 548 pp. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0093972/manifest

Comment

Related Items