ABSTRACT
The subfamily Meliponinae (stingless bees) is considered first because it is believed to have been the earliest to branch off from less social ancestors and develop highly social behaviour (Winston & Michener, 1977). These bees are confined to tropical regions. In the 1950s a fossil stingless bee from the Miocene - which started perhaps 25 million years ago - was found in Mexico, preserved in solidified tree resin known as amber (Roth, 1958); it is closely related to living species and was named Trigona (Nogueirapis) silacea. More recently a fossil female stingless bee was found in amber from coniferous resin 80 million years old, i.e. from the late Cretaceous (Grimaldi, 1988; Michener & Grimaldi, 1988). This bee (Figure 2.2a) is the oldest known specimen of social bees, and its discovery doubles their previously established antiquity. It was named Trigona prisca, and it has characteristics known in a living species.
