UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The impact of Tomicobia tibialis (Hymenoptera : pteromalidae) on the pine engraver, Ips pini (Coleoptera : scolytidae) Senger, Susan Evelyn


Augmentative release of biological control agents against pest insects is a management tool that has been largely ignored in forestry due to a lack of understanding and means of producing potential agents. I investigated the effects of Tomicobia tibialis Ashmead on the reproductive potential of adult Ips pini (Say) by comparing the reproductive indices of parasitized and healthy adult beetles maintained together in different combinations in pine logs. From these experiments I determined that the parasitoid most greatly impacts female beetle reproductive performance resulting in shorter gallery lengths and decreased offspring production before the female dies. Male beetle reproductive success depended on the females in his harem; however, the parasitized male cannot go on to subsequent infestations as a healthy male may. Thus the overall reduction in beetle reproduction resulting from parasitism can be substantial. Laboratory rearing methods for T. tibialis using pine logs were also established, and an attempt to rear these parasitoids from beetles held on artificial medium was made. In sum, it is possible to rear this parasitoid and the impact on its host beetle is better understood. I feel further investigation into augmentation using T. tibialis against I. pini is warranted.

Item Media

Item Citations and Data


For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.