Brachypterolus pulicarius is a natural enemy of both Dalmation [Linaria genistifolia spp. dalmatica (L.)] and yellow toadflax (Linaria vulgaris Mill.), two economically important invasive weeds. Toadflaxes were intentionally introduced into North America early in the last century as ornamentals and for medicinal uses. B. pulicarius was accidentally introduced, arriving along with its host weeds. Because the beetle exists on the two toadflax species, researchers have questioned whether B. pulicarius may actually consist of two distinct host races, one that is more adapted to yellow toadflax and one more adapted to Dalmation toadflax. Preliminary isozyme research indicated phenotypic differences between populations collected from the two different plants, suggesting the possibility of genetic differences. Current research involved further analyses of population differences utilizing the amplified fragment length polymorphism (AFLP) genetic technique. Analyses were completed on individuals collected from various populations in Northwestern Canada and the United States, as well as those collected by cooperators in Europe. Additionally, behavioral assays utilizing a Y-tube olfactometer and a wind tunnel sought to determine if B. pulicarius individuals show an actual preference for their particular host plant species. Research findings may have practical implications for biological control practitioners attempting to more perfectly match bio-control agents to their target weed.
Species 1: Coleoptera Nitidulidae Brachypterolus pulicarius
Keywords: host races
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA