\Genetics of differences in host range of a generalist and specialist herbivore

North Carolina State University, Raleigh NC

Investigators

Abstract

9981671 Gould Animal species fit along a continuum from generalists, which utilize a broad array of foods and habitats, to specialists, which have very specific requirements. Some plant-feeding insects can successfully consume leaves from hundreds of diverse plant species, but most of these insects specialize on one to a few plant species. In contrast, the majority of devastating crop pests are generalists. One of these, Heliothis virescens, is a major cotton pest but also feeds on tomatoes, soybean, tobacco and other non-agricultural plants. Heliothis subflexa is closely related to H. virescens but is an extreme specialists, only feeding on some species of Physalis (Chinese lantern plant). These two insect species can be hybridized and the offspring backcrossed to the specialist. The genetically segregating backcross offspring vary in degree of specialization. A molecular gene mapping technique, Amplified Fragment Length Polymorphism, will be used to determine which genes in these hybrid offspring enable them to consume the generalist species food plants. Information gained from this genetic mapping research will be used to examine how genes interact in determining the ecological niche of a species, and could provide tools for decreasing the genetic potency of pests.