Food Niche of Solitary and Social Bees (Hymenoptera: Apoidea) in a Neotropical Savanna

Abstract

In this study, we investigated the group of floral resources that support bee populations in a savanna area and how bee species use these food resources, with an emphasis on the breadth and overlap of trophic niches. The interactions between 75 bee species and 62 plant species were recorded on a Brazilian savanna area. The bee species explored a diverse set of plant species, but concentrated the collection of resources in a few species. The trophic niche breadth of the eusocial bees ranged from 0.77 to 2.59, while in non-eusocial bees the variation was from 0.35 to 1.99. The distribution of the samples over a long period favored a robust characterization of the food niche of the bee populations. Byrsonima sericea, Serjania faveolata, and Stigmaphyllon paralias were the plant species with the highest number of links with bees. In general, the trophic niche overlap was low, with 75% of pairs of bee species having a niche overlap (NO) less than 0.33. Only four pairs showed high overlap (NO>0.70) and all cases were related to the exploitation of floral resources provided by B. sericea, a key resource for the maintenance of the local bee fauna, an oil and pollen provider.