RESOURCE PARTITIONING BETWEEN HIGHLY EUSOCIAL BEES AND POSSIBLE IMPACT OF THE INTRODUCED AFRICANIZED HONEY-BEE ON NATIVE STINGLESS BEES IN THE BRAZILIAN ATLANTIC RAIN-FOREST

The highly eusocial bee community of the neotropical Atlantic Rainfore st was studied at Boraceia Biological Station in the state of Sao Paul o, Brazil. In this reserve, 17 species of stingless bees and the intro duced Africanized honey bee were found, the latter being the most abun dant flower visitor. Of all flowering plants, Asteraceae and Myrtaceae were particularly important as resources for bees. Trophic niche over lap between the various species of stingless bees is evident and it wa s generally larger within the tribes Meliponini and Trigonini than bet ween members of different tribes. Nevertheless, in the stingless bee c ommunity the competitive pressure is rather uniformly spread. The trop hic niche of the Africanized honey bee can be positioned between those of Meliponini and Trigonini. Today this introduced species represents the main competitor in this bee community. However, its impact on nat ive stingless bee populations is apparently buffered by mass-flowering trees which are the most important food plants of the indigenous high ly eusocial bees.