The effect of host plant species in the phenotypic and genetic differentiation of hymenopteran parasitoids

The ecology of parasitoids is strongly influenced by the host-plants of their hosts. Parasitoid fitness is affected by a variety of plant traits. Thus, it is reasonable to assume that adaptation to plant traits could promote phenotypic and genotypic differentiation among populations of parasitoids. I present data on phenotypic and genotypic differences of two braconid parasitoids ovipositing on the same host species on different host-plant species. I compare adult mass, adult longevity, and percent parasitism of a generalist (Cotesia marginiventris Cresson, Hymenoptera: Braconidae) and of a specialist parasitoid (Aleiodes nolophanae Ashmead, Hymenoptera: Braconidae) of the green cloverworm (Plathypena scabra Fabricius, Lepidoptera: Noctuidae) on alfalfa and soybean and use AFLP markers to assess genetic differences in parasitoids emerging from the same host species on alfalfa and soybean plants. The role of host-plants as promoters of host associated differentiation of higher trophic levels is discussed.