Discrimination and preferences for pollen-based cues by foraging honeybees, Apis mellifera L

• Published in: Animal behaviour 2002-02, Vol.63 (2), p.369-390
• Main Authors: Pernal, S.F., Currie, R.W.
• Format: Article
• Language: English
• Subjects: Animal behavior; Apidae; Apis mellifera; Bees; Biological and medical sciences
• ISSN: 0003-3472; 1095-8282
• DOI: 10.1006/anbe.2001.1904

We evaluated the influence of pollen-based cues on the foraging decisions made by honeybees using a series of two-choice bioassays, performed within a highly controlled indoor environment. We examined behaviours related to the choice and collection of pollen by foragers among six floral species and three artificial substrates (pollen analogues). First, we evaluated the responses of honeybees to the odours produced by different pollens (or pollen analogues) and pollen lipid extracts. Honeybees displayed similar levels of preference to the odours produced by all pollen species over those of pollen analogues, with a similar pattern of response shown to their extracts. We then evaluated behaviours of foragers in response to variation in particle size, using soybean meal that was ground and sifted to create a hierarchy of particle size classes. Bees preferred particle sizes below 150μm, but the greatest response was shown for those particle sizes below 45μm. We also assayed the effect of varying protein content on the foraging decisions made by bees by mixing soy flour with different proportions of cellulose powder. Foragers, however, were incapable of discriminating protein content. We determined changes in the response of foragers to different levels of handling time using different sized screens through which bees were forced to crawl to reach an attractive pollen odour source. In these tests, pollen-seeking behaviours were seen to decrease with increases in handling time. When odour was presented simultaneously with other stimuli, it was the primary and overriding cue used by bees to select pollen. These results suggest that individual honeybee foragers do not discriminate among pollen sources based on intrinsic differences in quality, but instead evaluate cues that may increase their efficiency of collection and recruitment to such a food resource.