Citation. Morrow, P. A.; Tonkyn, D. W.; Goldburg, R. J. 1989. Patch colonization by Trirhabda canadensis (Coleoptera: Chrysomelidae): effects of plant species composition and wind. Oecologia 81:43-50.   [1108  LTER]

Summary. The goldenrod leaf beetle, Trirhabda canadensis, is known to respond to odors of host and non-host species in the laboratory. Here we report movements of T. canadensis in the field in response to volatile odors from monocultures and polycultures of host plants. Overall, beetles preferentially colonized plots with a higher density of host plants and lower diversity of allelochemicals, but under some wind conditions there were marked exceptions. At high windspeeds, they colonized whichever plot(s) was up-wind. At low windspeeds, beetles colonized preferred plots even when they were not upwind. The data suggest that odor dispersion varies in a complex way with windspeed: at low windspeeds beetles received information from a wide arc of vegetation and made choices while at high windspeeds information was available only from upwind plot(s).

Keywords. Solidago altissima, Trirhabda canadensis, Host plant odors, Insect host colonization, Host finding, Odor dispersion