Feeding and attraction of Agelastica coerulea (Coleoptera: Chrysomelidae) to Betulaceae plants.

The feeding and attraction of Agelastica coerulea (Baly) to nine species of Betulaceae in four genera (Alnus, Betula, Carpinus, and Corylus) were examined in the laboratory by using choice and no-choice as well as olfactometer bioassays. In no-choice feeding bioassays with A. coerulea larvae, Alnus hirsuta (Spach) Ruprecht, Alnus japonica Steudel, Corylus sieboldiana variety mandshurica (Max.) c. k. Schneider, and Corylus heterophylla variety thunbergii Blume were the most preferred, whereas Betula davurica Pallas, Betula schmidtii Regel, and Carpinus cordata Blume were the least preferred. The larvae showed moderate preference for Alnus maximowiczii Callier and Carpinus tschonoskii variety brevicalycina Nakai. In choice feeding bioassays, no differences in preference between A. hirsuta and A. japonica were observed. However, there were significant differences in preference between A. hirsuta and each of the other seven plant species. In olfactometer bioassays with adult female A. coerulea, fresh leaf odor from A. hirsuta attracted significantly more adults than that from A. japonica and C. sieboldiana variety mandshurica. These results indicate that A. coerulea differed in its ability to discriminate among the Betulaceae plants at the feeding preference and attraction of host selection.