Crop and Semi-Natural Habitat Configuration affects Diversity and Abundance of Native Bees (Hymenoptera: Anthophila) in a Large-Scale Cotton Agroecosystem

Abstract

The cotton agroecosystem is one of the most intensely managed, economically, and culturally important fiber crops worldwide including in the United States of America (U.S.), China, India, Pakistan, and Brazil. The composition and configuration of crop species and semi-natural habitat can have significant effects on ecosystem services such as pollination. Here we investigate the effect of crop and semi-natural habitat configuration in a large-scale cotton agroecosystem on the diversity and abundance of native bees. Interfaces sampled include cotton grown next to cotton, sorghum or semi-natural habitat. Collections of native bees across interface types revealed 32 species in 13 genera across 3 families. Average species richness ranged between 20.5 and 30.5 with the highest (30.5) at the interface of cotton and semi-natural habitat. The most abundant species was Melissodes tepaneca Cresson (> 4,000 individuals, ~75% of bees collected) with a higher number of individuals found in all cotton-crop interfaces compared to the cotton interface with semi-natural habitat or natural habitat alone. It was also found that interface type had a significant effect on the native bee communities. Communities of native bees in the cotton-crop interfaces tended to be more consistent in the abundance of species and number of species at each sampling site. While cotton grown next to semi-natural habitat had higher species richness, the number of bees collected varied. These data suggest that native bee communities persist in large-scale cotton agroecosystems and some species may thrive even when cotton-crop interfaces are dominant compared with semi-natural habitat. These data have native bee conservation implications that may improve potential pollination benefits to cotton production.