Andrena accepta

Justification:
The two-spotted miner bee (Andrena accepta) is a widespread species that occurs across much of the United States and has also been recorded in Mexico. The extent of occurrence, based on all known records for this species is 6,259,516 km2. Within the range of the species, increased urbanization and agricultural development have been observed, so it is possible that localized threats are acting on this species, but currently, there are no clear threats to the species at a range-wide scale. Although A. accepta is a dietary specialist, its primary forage plants (Asteraceae) are abundant, widespread, and occur in many different habitats. However, further research is needed to establish full details of population size, trends, and threats to the species. For now, this species is assessed as Least Concern.

This species is a pollen specialist that visits plant species from the family Asteraceae for pollen, mostly those in the genus Helianthus. It has also been associated with other Asteraceae genera including Silphium, Grindelia, Aster, Bidens, Coreopsis, and Solidago (Mitchell 1960; LaBerge 1967). This species has been associated with several LANDFIRE habitat types, including agricultural and developed lands, mixed evergreen-deciduous shrubland, and perennial graminoid grassland (Chesshire et al. 2023). This species is solitary and builds nests in the ground that may be shared by more than one female (Danforth et al. 2019; Rozen 1973). This is the only species of Andrena reported to nest communally, all others are solitary nesting (Danforth et al. 20000). The nest cells are at the ends of the lateral burrows, which are typically lined with a waxy Dufour’s gland secretion (Rozen 1973; 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). In the single described nest of this species from southeastern Arizona, there were 23 larval cells, located at depths of between 31 and 56 cm (Rozen 1973), and 11 females. Females provision each cell with a ball of pollen moistened with nectar on which they lay a single egg (Michener 2007). This species appears to overwinter as larvae rather than adults as do some species of Andrena. Observations of this bee are from July through October, with most observations occurring in August and September (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019). Habitat:

The two-spotted miner bee occurs within several federally protected areas, including Grand Staircase Escalante National Monument (Carril et al. 2018), Mesa Verde National Park, and Badlands National Park (Chesshire et al. 2023). Given the widespread range of this species, it likely occurs in additional protected areas. Further research is needed to determine the overall size of the population and to identify trends and better understand 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 bee's adult 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.

(a. any taxonomic concerns about the validity of the species? b. any taxonomic revisions underway that would require a species reassessment?):