The Persistence of Bumble Bees (Hymenoptera: Apidae) in Northeastern Texas

Abstract

The bumble bee (Bombus spp.) fauna of Texas has been infrequently studied and few modern surveys have been conducted to assess the current status of the state's species. A significant body of research has documented declines for bumble bee species across several continents including North America. Historically, six bumble bee species have been recorded from northeastern Texas: B. griseocollis (De Geer 1773), B. bimaculatus Cresson 1863, B. impatiens Cresson 1863, B. variabilis (Cresson 1872), B. fraternus (Smith 1854), and B. pensylvanicus (De Geer 1773). Three of those (B. fraternus, B. pensylvanicus, and B. variablis) are considered potentially threatened given evidence of range-wide declines. However, the current status of these species in northeast Texas has not been addressed. In this study we perform field surveys of bumble bees in northeastern Texas and compare those data to historical specimen records to evaluate the current status of historically present species. We confirm that B. fraternus, B. griseocollis, and B. pensylvanicus persist across the study region. The remaining species, B. bimaculatus, B. impatiens, and B. variabilis, were historically rare in the study region and were not detected in the present study; the two former are on the western edge of their ranges in Texas and the latter is a cleptoparasitic species that is inherently difficult to detect. The results of this study establish current bumble bee persistence in northeast Texas and can serve as a departure point for future assessments of bumble bee species dynamics.