Attraction of the invasive social wasp, Vespula vulgaris, by volatiles from fermented brown sugar.
The introduction of invasive social wasp species of the genus Vespula (Hymenoptera: Vespidae) to New Zealand has caused a major ecological problem, particularly in the beech forests (Nothofagus spp.) of the South Island, where they have destabilized the native bird and invertebrate biodiversity. New attractants are under investigation as part of a search for pest management solutions. Fermenting brown sugar has been previously reported as a social wasp attractant. This work was undertaken to identify compounds from fermented brown sugar attractive to social wasps. Raw fermented brown sugar was confirmed to be attractive in a field trial and 10 chemical compounds present in the headspace were positively identified by coupled gas chromatography-mass spectrometry and synthetic references. During electroantennogram experiments, 3-methyl-1-butanol, 3-methylbutyl acetate, and ethyl hexanoate elicited high electrophysiological responses from Vespula vulgaris (L.) antennae. These compounds mediated attraction of V. vulgaris wasps in forest margins by trapping. A blend of these compounds could be used as a lure in a monitoring tool, or even a local suppression method if combined with a toxin.