Apidologie 36 (2005) 547-557
DOI: 10.1051/apido:2005042

Unlike nectar foragers, honeybee drones (Apis mellifera) are not able to utilize starch as fuel for flight

Norbert Hrassnigg, Robert Brodschneider, Paul H. Fleischmann and Karl Crailsheim

Institute for Zoology, Karl-Franzens-Universität Graz, Universitätsplatz 2, A-8010 Graz, Austria

(Received 8 April 2004 - revised 11 February 2005 - accepted 21 February 2005; Published online: 19 October 2005)

Abstract - Nectar foragers collected at a feeding station and fed 10 µL of a 2 molar glucose solution, increased their period of flight in a roundabout by 30.2% when they were fed additional soluble starch (10 µL, 2 M glucose + 1 M glucose equivalents as amylose). The increase in flight period and flight distance was about the same as for workers fed a pure 3 molar glucose, or another glucose plus starch solution (2.5 M glucose + 0.5 M glucose equivalents). In drones, feeding additional starch did not alter the flight period or the distance flown, either in normal or dwarf drones. Feeding honey plus starch did not alter the flight period, although the honey contained some starch-degrading amylase. The longer oligosaccharides in syrup produced by starch hydrolyses are said to have a negative impact on overwintering bees. However, from our results we infer that nectar foragers are well equipped with enzymes to efficiently degrade amylose to glucose, which underlines the workers' central role as food processors within the honeybee colony.

Key words: Apis mellifera / digestion / amylose / amylase / flight metabolism / enzyme

Corresponding author: Norbert Hrassnigg norbert.hrassnigg@uni-graz.at

© INRA, DIB-AGIB, EDP Sciences 2005