PARENT SESSION
Oral Session #101: Plant-Animal Interactions.
Presiding: S. Faeth
Friday, August 9. 9:00 AM to 12:00 PM. Coconino Meeting Room, TCC.

Effects of non-native plants on the population genetics of native phytophagous insects: a case study.

Oliver, Jeffrey^*,1,2, Shapiro, Arthur², ¹ EPO Biology, Boulder, CO² Evolution and Ecology, Davis, CA

ABSTRACT- Many insects have recently incorporated non-native plants into their host diet. These novel hosts may offer reduced predation risk and more stable resource availability. Non-native plants that are widely distributed, such as agricultural crops and invasive weeds, may prevent phytophagous insect population subdivision by supporting large, geographically widespread insect populations. Two native insect species, Everes comyntas and E. amyntula (Lepidoptera: Lycaenidae), offer an opportunity to test the hypothesis that non-native host plants may prevent population subdivision. Everes comyntas feeds on native and non-native hosts, while E. amyntula feeds only on native hosts. We sequenced approximately 550 bp of the mitochondrial cytochrome oxidase II gene in order to quantify the genetic diversity of each species. The intraspecific pairwise sequence divergence was significantly higher in Everes amyntula than in E. comyntas. This suggests that non-native hosts, such as alfalfa, used by E. comyntas are supporting a continent-wide, panmictic population, resulting in reduced genetic diversity. These results are important in understanding the effects of non-native plants on the population genetics of native phytophagous insects.

KEY WORDS: lepidoptera, non-native plants, phytophagous insects, Everes