NATURAL HISTORY OF THEOIL-COLLECTING BEES
Keywords:Oil-flowers, Centridini, Tapinotaspidini, Tetrapediini, Apoidea.
There are about 330 species of bees that use oil collected from flowers to feed the larvae and to surface the brood cells, they belong to the Melittinae (Melittidae), Ctenoplectrini, Centridini, Tapinostapidini and Tetrapediini (Apidae). From these groups the last three tribes are exclusively from the west hemisphere and especially diverse in the Neotropical region. Oil-bees have modifications on the legs or sternum (Tapinotaspoides) to sample, manipulate and transport the oil. These structures are usually correlated with the different type of elaiophores (the oil secreting glands): epithelial or trichomatic. It is estimated that more then 1800 plant species of 9 families offer floral oil as resource, being Malpighiaceae the most important. In this study we organized a revision about the nesting process of some oil collecting bees as well their association to the oil plants. The oilbees are most solitary, but some nest aggregated. The ground nesting species use flat soil or banks (like Epicharis, Monoeca, Lanthanomelissa), and there are some that use nest of termites and ants (like Ptilotopus), or wood pre-existing cavities (like Tetrapedia). Parasites are usually cleptoparasite bees like Coelioxys, Coelioxoides, Mesoplia, Mesocheira, Protosiris, Paraepeolus that oviposite inside the brood cell and their larvae (with sharp mandibles) kill the host egg or larvae. Besides all the knowledge accumulated about the oil-colleting bees some questions remain open about the use of this product.