ASPECTS OF THE TROPHIC NICHE OF MELIPONA MARGINATA MARGINATA LEPELETIER (APIDAE, MELIPONINAE)

Abstract

Pollen and honey samples were colleted once every two weeks from the food pots of two colonies of Melipona marginata marginata Lepeletier for a twelve-month period (August/ 1981 to July/ 1982). Altogether, 173 pollen types were found, belonging to 38 plant families in the samples from both colonies, although the really important sources (with representation of 10 % or over) for good collection were represented by only 11 plant species (9 in pollen samples and 8 in honey samples) belonging to six families. An interesting point is that from all the visited plant species, the most represented in both type of samples were trees. The plant families which occured most in pollen samples were : Myrtaccae, Solanaceae, Melastomataccae, and Leguminosae. In honey samples, the same sequence was observed, but the last two families appeared in the opposite order. The niche size as indicated by the number of pollen types fails to highlight the relative importance of plant species visited for food and assumes utilization of resources to be homogeneous. As regards niche size, as calculated by SHANNON –WEAVER diversity index, both colonics had lower values than any other bee species in the same area and used the sources visited least homogeneously. Summer was the season when both colonics showed the greatest similarity in terms of the sources visited for pollen. As far as honey samples arc concerned, autumn and early winter were the times when the two colonies overlapped most.