Abstract
Using direct observations and analyses of gut contents, we document that pollen feeding is widespread among female bombyliid flies. Pollen feeding is typically indirect with the initial pollen acquisition accomplished by foretarsal stroking of the anthers. Observations of the foretarsi using light and scanning electron microscopy showed that the foretarsi bear modified setae that play a role in pollen collection. Across the family, we found considerable variation in the morphology and distribution of the foretarsal setae that appear to be more related to phylogeny than pollen host. The major patterns of foretarsal setal specialization are illustrated and discussed.
References
Barth, F.G. (1985) Insects and Flowers: the Biology of a Partnership. Princeton University Press, Princeton, New Jersey.
Beattie, A.J. (1972) The pollination ecology of Viola. I: pollen loads of insect-visitors. Watsonia, 9, 13–25.
Deyrup, M.A. (1988) Pollen feeding in Poecilognathus punctipennis (Diptera: Bombyliidae). Florida Entomologist, 71, 597–605.
Du Merle, P. (1966) Modele de cage permettant d’obtenir la ponte d’un diptère Bombyliidae, Villa quinquefasciata Wied. apud Meig. Entomophaga, 11, 325–330.
Du Merle, P. (1971) Biologie de deux espèces du genre Usia Latreille (Dipt., Bombyliidae). ZOOTAXA Annales de la Société Entomologique de France (N. S.), 7, 241–259.
Dunlap-Pianka, H.L., Boggs, C.L. & Gilbert, L.E. (1977) Ovarian dynamics in heliconiine butterflies: programmed senescence versus eternal youth. Science, 197, 487-490.
Evenhuis, N.L. (2002) Catalog of the Mythicomyiidae of the world (Insecta: Diptera). Bishop Museum Bulletin in Entomology, 10, 1–85.
Evenhuis, N.L. & Greathead, D.J. (1999) Catalog of bee flies of the world (Diptera: Bombyliidae). Backhuys Publishers, Leiden. 656 p.
Gilbert, E.S. (1981) The foraging ecology of hoverflies (Diptera, Syrphidae): morphology of the mouthparts in relation to feeding on nectar and pollen in some common urban species. Ecological Entomology, 6, 235-262.
Grimaldi, D. (1988) Bee flies and bluets: Bombylius (Diptera: Bombyliidae) flower-constant on the distylous species, Hedyotis caerulea (Rubiaceae), and the manner of foraging. Journal of Natural History, 22, 1-10.
Holloway, B. (1976) Pollen-feeding in hover-flies (Diptera: Syrphidae). New Zealand Journal of Zoology, 3, 339–350.
Hull, F.M. (1973). Bee flies of the world. The genera of the family Bombyliidae. Smithsonian Institution Press, Washington, D.C. 687 p.
Knoll, F. (1921) Bombylius fuliginosus und die Farbe der Blümen. Abhandlungen der Zoologisch- Botanische Gesellschaft in Wien, 12, 17–119.
Motten, A.F., Campbell, D.T. & Alexander, D.E. (1981) Pollination effectiveness of specialist and generalist visitors to a North Carolina population of Claytonia virginica. Ecology, 62, 1278– 1287.
Müller, H. (1883) The Fertilisation of Flowers. (D’Arcy Thompson, trans.). MacMillan and Co., London.
Neff, J.L. & Simpson, B.B. (1985) Hooked setae and narrow tubes: foretarsal pollen collection by Trimeria buyssoni (Hymenoptera: Masaridae). Journal of the Kansas Entomological Society, 58, 730–732.
Robertson, C.H. (1892) Flowers and insects. IX. Botanical Gazette, 17, 269–276.
Roulston, T.H. & Cane, J.E. (2000) Pollen nutritional content and digestibility for animals. Plant Systematics and Evolution, 222, 187–209
Schneider, F. (1969) Bionomics and physiology of aphidophagous Syrphidae. Annual Review of Entomology, 14, 103–124.
Schremmer, F. (1961) Morphologische Anpassungen von Tieren — insbesondere Insekten — an die Gewinung von Blümennahrung. Verhandlungen der Deutsches Zoologisches Gesellschaft, 55, 375–401.
Simpson, B.B. & Neff, J.L. (1983) Evolution and diversity of floral rewards. Handbook of Experimental Pollination Biology (ed. C. E. Jones and R. J. Little), pp. 142-159, Van Nostrand Reinhold, New York.
Thorp, R.W. (1979) Structural, behavioral and physiological adaptations of bees (Apoidea) for collecting pollen. Annals of the Missouri Botanical Garden, 66, 788–812.
Toft, C.A. (1983) Community patterns of nectivorous adult parasitoids (Diptera, Bombyliidae) on their resources. Oecologia, 57, 200–215.
Toft, C.A. (1984) Activity patterns in two species of bee flies (Lordotus: Bombyliidae, Diptera): a comparison of species and sexes. Behavioral Ecology and Sociobiology, 14, 287–296
Williston, S.W. (1908) Manual of North American Diptera. Third edition. J.T. Hathaway, New Haven.
Yeates, D.K. (1994) Cladistics and classification of the Bombyliidae (Diptera: Asiloidea). Bulletin of the American Museum of Natural History, 219, 1–191.