Honeybee Foraging

Diesel exhaust fumes can rapidly degrade the floral odours used by honeybees (Apis melifera) to identify flowering plants, according to results published by scientists at the University of Southampton (Southampton, UK) in the journal Scientific Reports.¹

Lead author Tracey A. Newman told The Column that she was initially interested in investigating the impact of airborne pollutants on human health, specifically the effects on the human nervous system. At the time interest was growing in the causes of decreasing populations of honeybees, so her colleague and mentor suggested that she partner up with ecologist Professor Guy Poppy, to investigate the impact of airborne pollutants on honeybees. Newman said: “The end result was that the two of us, in close collaboration with Dr Robbie Girling, a chemical ecologist, worked up a couple of different proposals that drew together our key skills – neuro-immunology and ecology – to enable us to explore the impact of diesel exhaust on the honeybee nervous system and the impact on the chemical environment that the honeybee has to operate within.”

The team composed a synthetic blend of eight compounds found in oil seed rape flowers (Brassica napus) that were known to induce strong behaviour in honeybees. The aroma blend was entered into a closed glass vessel with either “clean” or diesel exhaust contaminated air. The volatile abundance of each chemical was measured by performing gas chromatography coupled to mass spectrometry (GC–MS). Two compounds out of the eight, α-farnesene (72.5% of the mixture) and α-terpinene (0.8% of the mixture), were undetectable after a 2 h exposure period. Of particular note is that removal of α-farnesene did not significantly reduce recognition of the aroma by trained honeybees, whereas removal of α-terpinene did. - B.D.

Reference

R. Girling, I. Lusebrink, E. Farthing, T. Newman, and G.M. Poppy, Scientific Reports DOI: 10.1038/srep02779 (2013).

This story originally appeared in The Column. Click here to view that issue.