Abstract
In their natural habitat foraging bumblebees refuse to land on and probe flowers that have been recently visited (and depleted) by themselves, conspecifics or other bees, which increases their overall rate of nectar intake. This avoidance is often based on recognition of scent marks deposited by previous visitors. While the term ‘scent mark’ implies active labelling, it is an open question whether the repellent chemicals are pheromones actively and specifically released during flower visits, or mere footprints deposited unspecifically wherever bees walk. To distinguish between the two possibilities, we presented worker bumblebees (Bombus terrestris) with three types of feeders in a laboratory experiment: unvisited control feeders, passive feeders with a corolla that the bee had walked over on its way from the nest (with unspecific footprints), and active feeders, which the bee had just visited and depleted, but which were immediately refilled with sugar–water (potentially with specific scent marks). Bumblebees rejected both active and passive feeders more frequently than unvisited controls. The rate of rejection of passive feeders was only slightly lower than that of active feeders, and this difference vanished completely when passive corollas were walked over repeatedly on the way from the nest. Thus, mere footprints were sufficient to emulate the repellent effect of an actual feeder visit. In confirmation, glass slides on which bumblebees had walked on near the nest entrance accumulated hydrocarbons (alkanes and alkenes, C23 to C31), which had previously been shown to elicit repellency in flower choice experiments. We conclude that repellent scent marks are mere footprints, which foraging bees avoid when they encounter them in a foraging context.
References
Attygalle AB, Aneshansley DJ, Meinwald J, Eisner T (2000) Defense by foot adhesion in a chrysomelid beetle (Hemisphaerota cyanea): characterization of the adhesive oil. Zoology 103:1–6
Butler CG, Fletcher DJC, Watler D (1969) Nest-entrance marking with pheromones by the honeybee Apis mellifera L., and by a wasp, Vespula vulgaris L. Anim Behav 17:142–147
Cameron SA (1981) Chemical signal in bumble bee foraging. Behav Ecol Sociobiol 9:257–260
Chapman RE, Wang J, Bourke AFG (2003) Genetic analysis of spatial foraging patterns and resource sharing in bumble bee pollinators. Mol Ecol 12:2801–2808
Chittka L, Williams NM, Rasmussen H, Thomson JD (1999) Navigation without vision: bumblebee orientation in complete darkness. Proc. R. Soc. Lond. B Biol Sci 266:45–50
Darvill B, Knight ME, Goulson D (2004) Use of genetic markers to quantify bumblebee foraging range and nest density. Oikos 107:471–478
Dornhaus A, Brockmann A, Chittka L (2003) Bumble bees alert to food with pheromone from tergal gland. J Comp Physiol A 189:47–51
Eltz T (2006) Tracing pollinator footprints on natural flowers. J Chem Ecol 32:907–915
Federle W, Riehle M, Curtis ASG, Full RJ (2002) An integrative study of insect adhesion: mechanics and wet adhesion of pretarsal pads in ants. Integr Comp Biol 42:1100–1106
Gawleta N, Zimmermann Y, Eltz T (2005) Repellent foraging scent recognition across bee families. Apidologie 36:325–330
Goulson D, Hawson SA, Stout JC (1998) Foraging bumblebees avoid flowers already visited by conspecifics or by other bumblebee species. Anim Behav 55:199–206
Goulson D, Stout JC, Langley J, Hughes WOH (2000) Identity and function of scent marks deposited by foraging bumblebees. J Chem Ecol 26:2897–2911
Jandt JM, Curry C, Hemauer S, Jeanne RL (2005) The accumulation of a chemical cue: nest-entrance trail in the German yellowjacket, Vespula germanica. Naturwissenschaften 92:242–245
Jarau S, Hrncir M, Zucchi R, Barth FG (2005) Morphology and structure of the tarsal glands of the stingless bee Melipona seminigra. Naturwissenschaften 92:147–150
Jiao Y, Gorb S, Scherge M (2000) Adhesion measured on the attachment pads of Tettigonia viridissima (Orthoptera, Insecta). J Exp Biol 203:1887–1895
Kosaki A, Yamaoka R (1996) Chemical composition of footprints and cuticular lipids of three species of lady beetles. Jpn J Appl Entomol Zool 40:47–53
Lockey KH (1988) Lipids of the insect cuticle: origin, composition and function. Comp Biochem Physiol B 89:595–645
Marden JM (1984) Remote perception of floral nectar by bumblebees. Oecologia 64:232–240
Oldham NJ, Billen J, Morgan ED (1994) On the similarity of the Dufour gland secretion and the cuticular hydrocarbons of some bumblebees. Physiol Entomol 19:115–123
Saleh N, Chittka L (2006) The importance of experience in the interpretation of conspecific chemical signals. Behav Ecol Sociobiol 61:215–220
Schmidt VM, Zucchi R, Barth FG (2005) Scent marks left by Nannotrigona testaceicornis at the feeding site: cues rather than signals. Apidologie 36:285–291
Schmitt U, Bertsch A (1990) Do foraging bumblebees scent-mark food sources and does it matter? Oecologia 82:137–144
Schmitt U, Lübke G, Francke W (1991) Tarsal secretion marks food sources in bumblebees (Hymenoptera: Apidae). Chemoecology 2:35–40
Stout JC, Goulson D (2002) The influence of nectar secretion rates on the responses of bumblebees (Bombus spp.) to previously visited flowers. Behav Ecol Sociobiol 52:239–246
Stout JC, Goulson D, Allen JA (1998) Repellent scent-marking of flowers by a guild of foraging bumblebees (Bombus spp.). Behav Ecol Sociobiol 43:317–326
Thomson JD, Chittka L (2001) Pollinator individuallity: when does it matter? In: Chittka L, Thomson JD (eds) Cognitive Ecology of Pollination. Cambridge University Press, pp 191–213
Votsch W, Nicholson G, Muller R, Stierhof YD, Gorb S, Schwarz U (2002) Chemical composition of the attachment pad secretion of the locust Locusta migratoria. Insect Biochem Mol Biol 32:1605–1613
Witjes S, Eltz T (2007) Influence of scent deposits on flower choice: experiments in an artificial flower array with bumblebees. Apidologie 38:12–18
Acknowledgements
We thank Sebastian Witjes for advice and help with the experiments. Klaus Lunau and the members of Sensory Ecology Seminar provided critical comments that improved the manuscript. The experiments comply with the current laws of Germany. This study is supported by DFG grant EL 249/4.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
ESM 1
(DOC 557 kb)
Rights and permissions
About this article
Cite this article
Wilms, J., Eltz, T. Foraging scent marks of bumblebees: footprint cues rather than pheromone signals. Naturwissenschaften 95, 149–153 (2008). https://doi.org/10.1007/s00114-007-0298-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00114-007-0298-z