Bald-faced hornet hydrocarbons serve as a barrier to moisture diffusion and thus prevent dehydration in wasps. Cuticular hydrocarbon profiles vary over species and nests, and so cuticular hydrocarbons are a proposed mechanism for nest-mate recognition. Worker and queen cuticular lipids have similar components, but their distributions differ dramatically, implying that cuticular hydrocarbons also play a role in caste differentiation. The following lipid profiles were determined from specimens collected in the summer and early fall of northeastern Georgia in 1989. The dominant hydrocarbons recovered from the cuticles of workers were n-alkanes and methyl branched and dimethyl branched alkanes with a C27 or a
Bald-faced hornet temporal specifics vary depending on location. In Washington State, nest initiation occurs during mid-May, and workers emerge during mid-June. Large cell building starts during mid-July, and the first queens emerge during mid-August. The colony terminates during mid-September, for a life cycle of approximately four months (122 days). Lower latitudes correlate with longer life cycles. In Indiana, colonies were observed to begin in early May and terminate in late September, a life cycle of five months (153 days), and in Central California nests are initiated as early as the end of March. These nests survive between 155 and 170 days. Active