Arthropod inhabitants and architecture of Xylocopa virginica nests from Georgia, United States.

The Eastern Carpenter Bee, Xylocopa virginica (Linnaeus 1771), plays an important role in both pollination and diversity in anthropogenic environments, yet is often considered a pest due to its nesting behavior in wooden structures. In this study we explored the nest architecture, arthropod communities, and wood displacement caused by X. virginica in Georgia (Athens, Clark Co., USA). Seven naturally infested boards from wooden benches containing carpenter bee nests were sampled from the University of Georgia in mid-summer 2023. Our objectives were to investigate nest construction, catalog arthropod inhabitants, and assess carpenter bee mandible and wing wear as indicators of reproductive status. Results showed that X. virginica internal nest galleries ranged from single-hole to complex multi-hole structures, with varying degrees of brood development. A variety of arthropods, including parasitoids and commensals, were found inhabiting the nests. The amount of wood displaced by X. virginica ranged from 6% to 18% of the board volume, with galleries excavated by bees forming the structure of the nests. Mandible wear scores (MWS) and wing wear scores (WWS) of adult females suggested varying levels of foraging activity and potential reproductive status. Although most nests contained typically organized brood and adults, some nests showed anomalies. These findings highlight the role of X. virginica nests in supporting diverse arthropod communities and suggest the amount of wood displaced by bees is unlikely to significantly compromise structural integrity. Our study calls for a reconsideration of the pest status of X. virginica, while emphasizing its contribution to biodiversity and ecosystem services.