Andrena coconina

Justification:
Andrena coconina is a solitary bee species known from only seven observations from the western United States and Canada. Using all verified records, its extent of occurrence is 969,027 km2, however it has not been observed from anywhere in its range since 2005. Using all verified records, its area of occurrences (AOO) is 20 km2. It is known from only five localities, which make up five locations, two of which are directly threatened by overgrazing and land cover change due to urbanization and/or agricultural expansion. This is accompanied by ongoing and projected habitat decline across its range due to climate change. Because this rarely collected species was more recently described (1980), it is possible that there are more records of this species that are misidentified or unidentified. As such, there is a moderate degree of uncertainty with regards to its range limits, AOO, and number of locations. However, given the lack of recent records, small AOO, low number of locations, and ongoing threats across its range, this species is ranked as Endangered based on available information for now. It should be reassessed in the event that more records become available.

There is almost no available information about the habitat and ecology of this species. The dietary breadth is unknown, and there are no available foraging records. It has been observed in forests, shrublands 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 July (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

There have been no specific threats identified for this species, however, it may be threatened by extreme drought ongoing within its range. Since 2000, the Southwest U.S. has seen the worst drought in 1200 years (Williams, Cook, and Smerdon 2022). Drought can reduce the abundance of flowering plants on a landscape scale, and also reduce pollen and nectar quality (Wilson Rankin, Barney, and Lozano 2020). Drought conditions have been shown to reduce the diversity and abundance of native bees (Minckley, Roulston, and Williams 2013; Hung et al. 2021). There are five localities documented for this species, representing five locations. Of these, two are directly threatened. One location, north of Mariposa, California, shows high modeled land cover vulnerability to change (Clark University 2021), which predicted human-based land cover change due to agriculture and development. A second location, within the Grand Staircase Escalante National Monument, occurs within a Bureau of Land Management (BLM) grazing allotment that has failed to meet the agency's own health standards, with this failure attributed to grazing (BLM 2022). Overgrazing on this allotment may contribute to reduced quality and quantity of forage for the bee in this area. Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena coconina 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 Bureau of Land Management (BLM) and United States Forest 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.

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