Social wasps (Hymenoptera: Vespidae) trapped with acetic acid and isobutanol

The combination of acetic acid and isobutanol is attractive to different species of Vespidae in different areas of the United States. In Washington, the blend was attractive to workers and queens of Vespula pensylvanica (Saussure), Vespula germanica (F.), and workers of Dolichovespula maculata (L.). In Maryland, these chemicals were attractive to worker Vespula maculifrons (Buysson), worker V. germanica, worker Vespula squamosa (Drury), worker D. maculata, worker Vespa crabro L., and female Polistes dominulus F. In Oklahoma, the blend was attractive to worker V. maculifrons, worker V. squamosa, female Polistes fuscatus (F.), and Polistes annularis (L.). Several species were weakly attracted to acetic acid alone; V. maculifrons and D. maculata in Maryland, and V. squamosa, V. maculifrons, P. fuscatus, P. perplexus, and P. annularis in Oklahoma. Queens of V. germanica in Washington, workers of V. maculifrons in Maryland, as well as workers of V. squamosa and V. maculifrons in Oklahoma were weakly attracted to isobutanol alone.