Behavioural responses of the small hive beetle to volatile components of fermenting honeybee hive products

The small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae), is a significant pest of managed honeybees in the USA and eastern Australia. The beetle damages hives by feeding on hive products and leaving behind fermented wastes. The beetle is consistently associated with the yeast Kodamaea ohmeri (Etchells & Bell) Yamada et al. (Saccharomycetales: Metschnikowiaceae), and this yeast is the presumed agent of the fermentation. Previous work has noted that the small hive beetle is attracted to volatiles from hive products and those of the yeast K. ohmeri. In this study, we investigated how the volatile compounds from the fermenting hive products change depending upon the source of the hive material and also how these volatiles change through time. We used gas chromatography–mass spectrometry and choice-test behavioural assays to investigate these changes using products sampled from apiaries across the established range of the beetle in eastern Australia. The starting hive products significantly affected the volatile composition of fermenting hive products, and this composition varied throughout time. We found 61.7% dissimilarity between attractive and non-attractive fermenting hive products, and identified individual compounds that characterise each of these groups. Eleven of these individual compounds were then assessed for attractiveness, as well as testing a synthetic blend in the laboratory. In the laboratory bioassay, 82.1 ± 0.02% of beetles were trapped in blend traps. These results have strong implications for the development of an out-of-hive attractant trap to assist in the management of this invasive pest.