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

Abstract

Simple SummaryCommercial cotton growing systems are one of the most intensely managed, economically, and culturally important fiber cropping systems worldwide. The composition and configuration of crop species and semi-natural habitat can have significant effects on ecosystem services such as pollination. Here, we investigated the local-scale effect on the arrangement of different crop fields and surrounding semi-natural habitat in a large-field commercial cotton system on the diversity and abundance of native bee pollinators. Using bee bowl traps at crop interfaces (cotton grown next to cotton, sorghum, or semi-natural habitat along with a natural habitat comparator), we found a total of 32 bee species in 13 genera across 3 families. The most abundant native bee was Melissodes tepaneca Cresson (>4000 individuals, ~75% of bees collected). A higher number of individuals were found in all cotton–crop interfaces compared to the cotton next to semi-natural habitat or natural habitat alone. Native bee communities were also found to be influenced by the crop interface. Communities of native bees in the cotton–crop interfaces tended to be more consistent in the number of bees and number of bee species. While cotton grown next to semi-natural habitat had a more diverse array of bees, the number of bees collected varied. These data suggest that native bee communities persist in large-field commercial cotton growing systems. Select species dominate (i.e., M. tepaneca) and thrive in this large-field cotton system where cotton–crop interfaces are key local landscape features. These data have implications for potential pollination benefits to cotton production. The findings contribute to a discussion regarding the role of large-field commercial cotton growing systems in conserving native bees.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 investigated the local-scale effect of crop and semi-natural habitat configuration in a large field (>200 ha in size) cotton agroecosystem on the diversity and abundance of native bees. The interfaces sampled included cotton grown next to cotton, sorghum or semi-natural habitat along with a natural habitat comparator. Collections of native bees across interface types revealed 32 species in 13 genera across 3 families. Average species richness metrics 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 (>4000 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 species richness and abundance. 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-field cotton agroecosystems. Selected species dominate (i.e., M. tepaneca) and thrive in this large-field cotton system where cotton–crop interfaces are key local landscape features. These data have implications for potential pollination benefits to cotton production. The findings also contribute to a discussion regarding the role of large-field commercial cotton growing systems in conserving native bees.