Andrena atlantica

Justification:
Andrena atlantica is a generalist bee species that occurs along the eastern coastal states of the United States, from eastern Texas north and East to Massachusetts. Using all records of the species, the extent of occurrence is 1,348,713 km2. Observations since 2013 are mostly centered around the Chesapeake and Delaware Bay areas, although there are several additional recent records that come from more widely dispersed localities. The species occurs in deciduous and coniferous forests, woody wetlands, and urban and agricultural areas. Across the range of the species, impacts from climate change, habitat loss and degradation, and exposure to pesticides has been observed. These threats may be acting on the species at local levels. More information is needed to track population trends, understand the life history of the species, and understand the degree to which these threats are acting on the species. However, because the species is relatively widespread, occurs in multiple ecosystems, and has been recently observed in several localities within its range, it is unlikely that it is threatened with extinction at this time. As such it is ranked as Least Concern for now.

Andrena atlantica appears to be a dietary generalist, visiting plants from a wide range of families for pollen. It has been recorded foraging from plants in the families Rosaceae, Salicaceae, Asteraceae, Anacardiaceae, and Aquifoliaceae, among others. Laberge (1971) notes that the species might have a preference for plants in the genus Rubus (Rosaceae), and Ilex (Aquifoliaceae). It has been recorded in grasslands, woody wetlands, evergreen and deciduous forests, and agricultural and urban areas. This species likely nests underground like all other Andrena (Danforth et al. 2019), but nests from this species have not been described. Nest cells from other members of this genus are located at the ends of the lateral burrows, which are typically lined with a waxy Dufour’s gland secretion (Cane 1981) that serves to both isolate the provision from pathogens in the surrounding soil and to regulate water uptake from the soil atmosphere (Cane and Love 2021). Females provision each cell with a ball of pollen moistened with nectar on which they lay a single egg (Michener 2007). Records of this species come from March through June, with most records from April and May (Laberge 1971; Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena atlantica is a ground nesting species, and nests may be harmed by certain agricultural practices such as tilling, which can kill bees nesting close to the surface (Williams et al. 2010). Additionally, Andrena have been reported to have low reproductive output because of the short adult life span, and a low rate of brood cell provisioning (reviewed in Danforth et al. 2019). Other threats to bees generally include habitat loss or modification, climate change, pesticide use, exposure to pathogens from managed bee species, and competition with honey bees (Brown and Paxton 2009; Potts et al. 2010; Wojcik et al. 2018; Grab et al. 2019; Raven and Wagner 2021).

Conservation needs No known conservation actions are in place for this species. Observations of this species are known from United States Forest Service, United States Fish and Wildlife, and National Park Service land, but this does not confer any specific protections to the species. Further research is needed to determine the overall size of the population and to identify trends and existing threats. Specific conservation needs for this species have not been identified. Due to the importance of supporting wild bee populations for pollination services, general conservation practices are recommended including, restoring, creating, and preserving natural high-quality habitats to include suitable forage and nesting sites; limiting pesticide use on or near suitable habitat, particularly during the adult bee’s flight period; promoting farming and urban practices that increase pollinator-friendly plants in margin space; minimizing exposure of wild bees to diseases transferred from managed bees; and lastly, avoiding honey bee introduction to high-quality native bee habitat.

Surveys targeting this species are needed throughout its range to determine its persistence throughout its historic range. More information is needed about the population status, range limits, habitat, and ecology of this species.

This species is closely related to Andrena alleghaniensis, and males of the two species are nearly indistinguishable. This contributes to the potential for errors in the dataset. In the revision of the species, Laberge (1971) states that these two species may be races of one species, but evidence is inconclusive, and it is better to keep names separate in the literature until more evidence becomes available.