Keith Roderick Hopper

Learn More
The host specificity of insect parasitoids and herbivores is thought to be shaped by a suite of traits that mediate host acceptance and host suitability. We conducted laboratory experiments to identify mechanisms shaping the host specificity of the aphid parasitoid Binodoxys communis. Twenty species of aphids were exposed to B. communis females in(More)
The Asian parasitoid, Binodoxys communis (Gahan) (Hymenoptera: Braconidae), is a candidate for release against the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America. In this study, we examined preferences by B. communis for the different developmental stages of A. glycines and investigated consequences of these(More)
We consider the possibility of an extensive invasional meltdown occurring in central North America involving eleven Eurasian species. The scenario begins with the potential co-facilitation between the European earthworm Lumbricus terrestris and European buckthorn, Rhamnus cathartica. Once introduced, European buckthorn has served as the overwintering host(More)
We discuss the potential pros and cons of using importation biological control against the soybean aphid, Aphis glycines Matsumura (Homoptera: Aphididae). Importation of exotic organisms for biological control is never completely risk-free, but the potential negative impacts of not achieving biological control of invasive pests may exceed the risks(More)
We infer the phylogeny of a complex of cryptic species and populations of parasitic wasps and examine how reproductive incompatibility maps onto the molecular phylogeny. We used four nuclear (28S-D2, ITS1, ITS2, ArgK) and two mitochondrial (COI, COII) gene regions to analyze relationships among populations in the Aphelinus varipes species complex(More)
Facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. Aphids (Hemiptera: Aphididae) are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolutionary processes in a dynamic selective environment. However, relatively(More)
Many insects are associated with heritable symbionts that mediate ecological interactions, including host protection against natural enemies. The cowpea aphid, Aphis craccivora, is a polyphagous pest that harbors Hamiltonella defensa, which defends against parasitic wasps. Despite this protective benefit, this symbiont occurs only at intermediate(More)
We used genetic mapping to examine the genetic architecture of differences in host plant use between two species of noctuid moths, Heliothis subflexa, a specialist on Physalis spp., and its close relative, the broad generalist H. virescens. We introgressed H. subflexa chromosomes into the H. virescens background and analyzed 1462 backcross insects. The(More)
The silent invasion of Hawaii by tato, barley, cassava, soybean, sugar insects, disease organisms, snakes, cane, and oats; Sattaur 1989, weeds and other pests is the single Most proponents of Prescott-Allen and Prescott-Allen greatest threat to Hawaii's economy and natural environment .... Even one new pest-like the brown tree snake--could forever change(More)