Nathan Rank Sonoma State University Evolution of host plant preference Introduction (Page 1 of 3) Introduction Species & Genes Sampled Results & Conclusions Research Home See also research summary. One can reconstruct evolutionary events by determining the evolutionary relationships among groups of species that vary with respect to a character of interest and then mapping the character onto the evolutionary tree. This approach can be used to learn about the process of host plant specialization in herbivorous insects. We used the beetle genus Phratora to reconstruct the evolutionary history of host plant use.. Species in this genus are relatively similar morphologically.. They differ greatly in host plant use and in the chemistry of their larval secretions. Head of an adult beetle Variation in host plant use in Phratora Introduction to Phratora. Leaf beetles in the genus Phratora are widely distributed across the Northern Hemisphere, but the genus is relatively small. There is relatively little variation in size or shape of Phratora larvae and adults. Yet these beetle species differ greatly in host plant use and in the chemistry of the secretion produced by their larvae. Most species feed on willows or poplars (family Salicaceae), but two species use birch. Larvae of most species produce an autogeneous secretion, but Phratora vitellinae uses salicylates from the leaves of its host plant to make salicylaldehyde. Phratora purpurea adult in Michigan Phratora vitellinae adult in Finland Third instar Phratora vitellinae larva Previous Page Next Page Research Home|Nathan Rank's Homepage |Department of Biology | Sonoma State University January 23, 1999 NER