Published online by Cambridge University Press: 08 February 2001
Primary flower resources to bees, i.e. those that satisfy basic needs, such as feeding and reproduction (Faegri & van der Pijl 1979), include pollen, nectar, oil, resin and gums. Resins are used in nest construction as a waterproof and structural material (Simpson & Neff 1981). It is also excellent antimicrobial compound, and a sticky defence against ant attacks (Armbruster 1984, Dressler 1982, Lokvam & Braddock 1999, Michener 1990, Roubik 1989, Sakagami et al. 1989). Plant species with flowers which produce terpenoid resins are rare (Armbruster & Webster 1979). Clusia L. (Clusiaceae), Clusiella Planch. & Triana (Clusiaceae), and Dalechampia L. (Euphorbiaceae) are the only known plants that secrete resins from floral structures (Armbruster 1984, Armbruster & Webster 1979, Bittrich & Amaral 1996). Although resin-producing plants provide an essential resource for a large number of bees in tropical communities, there are few studies about resin-collecting bees on Clusia spp. Skutch (1971) was the first to report visits on Clusia by stingless bees to collect floral resin. Other reports include observations on C. odorata Seem. (Croat 1978, Ramirez & Gomez 1978), C. alata Pl. & Tr. (Ramirez & Gomez 1978), and C. nemorosa G. F. W. Meyer (Armbruster 1984, Bittrich & Amaral 1996, Lopes & Machado 1998, Mesquita & Fransciscon 1995). Recently, Bittrich & Amaral (1996, 1997) have described the flower morphology and pollination biology of other Clusia species from Central America and Venezuela.