Location: Chemistry Research Unit
Title: Response of the small hive beetle (Aethina tumida) to a blend of chemicals identified from honeybee (Apis mellifera) volatiles Authors
|Torto, Baldwyn -|
|Suazo, Alonso -|
|Tumlinson Iii, James|
Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 14, 2005
Publication Date: September 13, 2005
Citation: Torto, B., Suazo, A., Alborn, H.T., Tumlinson Iii, J.H., Teal, P.E. 2005. Response of the small hive beetle (Aethina tumida) to a blend of chemicals identified from honeybee (Apis mellifera) volatiles. Apidologie. 36:523-532. Interpretive Summary: Small hive beetles are a serious pest of bee hives and adult weevils attraction to worker bees has previously been shown in olfactometer and windtunnel experients. In this investigation volatile compounds were collected of worker bees on adsorbent filters and the extracts tested in olfactometer assays. In addition, the response of weevil antennas to the extracts were investigated using coupled gas chromatographic-electroantennographic detection (GC-EAD). EAD-active components were identified by coupled gas chromatography-mass spectrometric analysis and shown to consist primarily of alcohols, aldehydes, ketones and esters. Among these were the honeybee alarm pheromone components isopentyl acetate and 2-heptanone and several floral volatile components. The olfactometer assays clearly showed that the volatile collection extract and a blend of the 8 most dominant constituents elicited dose dependent upwind responses, in agreement with previous results. However, neither treatment was as effective in wind tunnel assays as live caged bees. This suggested that minor components present in bee volatiles could play an important role in small hive beetle attraction. Future research will examine the contribution of other components in synergizing the attractiveness of the 8-component blend, and the development of this blend into an effective lure for trapping the small hive beetle.
Technical Abstract: Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of Super Q collected worker honey bee volatiles revealed several components that elicited antennal responses by the small hive beetle Aethina tumida. However, GC-MS analysis showed that eight of these EAD-active components dominated the volatile profile released into a wind tunnel by living adult worker honeybees and rubber septa impregnated with a Super Q extract of the volatiles of the bees in a 15-min bioassay. These components were identified as isopentyl acetate, 2-heptanone, octanal, hexyl acetate, nonanal, 2-nonanone, methyl benzoate and decanal. In dual-choice wind tunnel bioassays, the Super Q extract and a blend of the eight components elicited dose-dependent upwind responses from beetles relative to a solvent control. At 375-bee day equivalents, the Super Q extract and the 8-component blend elicited 76 and 74% upwind response, respectively, which compared with 84% response from approx. 150-200 living worker honey bees. In contrast, the Super Q extract and the 8-component blend lured only approx. 12 and 3% of beetles, respectively, into a trap compared to 48% by the odor from living adult worker bees.