XIII International Entomophagous Insects Workshop July 27-31, 2003, Tucson, Arizona

2003 Journal of Insect Science  
The parasitism of Diaprepes abbreviatus (L.) eggs by Ceratogramma etiennei Delvare as influenced by host age, age of the parasitoid, and host plant preference was evaluated. Percent parasitism of D. abbreviatus eggs by C. etiennei decreased as eggs matured under laboratory and greenhouse tests. One to 2 d old C. etiennei females parasitized more hosts than older females. Host plant leaf thickness, leaf pubescence and plant strata affected parasitism by C. etiennei. This parasitoid is diurnal
more » ... spends approximately 5 min probing, 46 min in actual parasitism per egg mass and 24 min resting. Natural enemies and the evolution of host range expansion in herbivorous insects Some recent theoretical research has suggested that natural enemies can retard or accelerate the rate of evolution of host range expansion in an herbivorous insect. Other theoretical results imply that natural enemy induced mortality may have little influence on the rate of evolution of host range expansion. This issue has attracted some interest when considered in the context of the evolution of resistance to transgenic Bt crops. I provide an overview to the various theoretical approaches to the problem and outline a set of circumstances where natural enemies could exert considerable selection pressure on an herbivorous insect to expand its host range. Colorado potato beetle hemolymph effects on the parasitic nematode Heterorhabditis marelatus Many species of parasitoids are distributed over populations in a variety of habitats in which they may experience different environmental conditions. If gene flow among these populations is limited and natural selection operates differently in the different habitats, this should lead to genetic divergence and local adaptation. Our study examines the effects of plant variation and the existence of local adaptation in a tri-trophic interaction. The system comprises four wild populations of the bean Phaseolus vulgaris, the bruchid beetle Zabrotes subfasciatus and the braconid parasitoid Stenocorse bruchivora. Transplant experiments revealed that bruchid performance varies among bean populations. Beetles from one site performed better on the seeds of their original site than on seeds of the other populations. A nutritional analysis of the seeds showed that seeds from this site are nutritionally superior as they have a higher nitrogen content. We then examined the consequences of bruchid variation on the performance and potential for local adaptation of the parasitoid. The results did not show evidence for local adaptation, but they showed behavioural and performance differences among parasitoid populations with respect to their origin and the origin of the seeds in which they developed. We currently study the role of the plant in determining genetic differences among populations. Patch quality, life expectancy and patch residence time in female egg parasitoids The figitids are a diverse assemblage of parasitic cynipoids. Intense systematic research over the past two decades has revealed much about this ubiquitous group, both taxonomically and phylogenetically. To aid in the study of figitid phylogenetics, I have sequenced the 28S D2+D3, COI and 16S gene regions while placing a premium on taxon sampling that represents the maximum diversity of the Figitidae. Additionally, several members of other cynipoid families have been included. The results to date find the majority of figitid subfamilies monophyletic. The goal of this research is a robust phylogeny that future studies on the classification and evolution of this group can be based upon. Migration by the sweet potato whitefly, Bemisia tabaci, and its aphelinid parasitoid Eretmocerus eremicus Information has been gathered for several years on the migration habits of the sweet potato whitefly, Bemisia tabaci. Empirical evidence demonstrates that this relatively small insect is easily capable of migrating several kilometers during a single morning. Anecdotal evidence indicates it can disperse much farther. Contrastingly, one of its principle natural enemies in the Southwest, Eretmocerus eremicus, seems less capable of moving even these modest distances. Regardless, an examination of their flight behavior has provided useful information. For example, when examined in the laboratory the ability of E. eremicus to sustain flight is linked to gender and mating status. Unmated females fly for significantly longer periods of time that do unmated females and females fly for significantly longer periods than males. Conclusions concerning flight behavior were substantiated in field trials where female dispersal had a strong directional component while males apparently International Entomophagous Insects Workshop. 2003. Abstracts from the XIII International Entomophagous Insects Workshop. 30pp. Journal of Insect Science, 3:33, Available online: insectscience.org/3.33 diffused away from release points. Taken collectively (see Bellamy presentation) these data provide insight into host/parasitoid relationships. The induction of volatiles in bean plants by feeding and oviposition of Nezara viridula that attract the egg parasitoid Trissolcus basalis: Behavioral and chemical ecology investigations. A recent study used a game theoretical approach to model patch leaving and oviposition behavior of two solitary parasitoid females depleting one patch. Optimal decisions on when to start Olfactory responses of Dicyphus hesperus Knight (Heteroptera: Miridae) to prey and plant odors. The biological control of the glassy-winged sharpshooter, Homalodisca coagulata, has received considerable attention over A biological control program was initiated to develop and implement strategies to manage Diaprepes abbreviatus (L.) in response to the spread of this weevil in Florida and the latest infestations in Texas and California. This classical biological control effort is collaborative, involving state, federal, private institutions and
doi:10.1093/jis/3.1.33 fatcat:tejnfsciyzacbbanc4qjyreuh4