Andrena papagorum

Justification:
Andrena papagorum is a solitary bee known from 25 observations. Most records are from the southwestern United States, although there are some additional records from Oregon, Montana, and Illinois. Using all known records for the species, the extent of occurrence is 2,356,668 km2. Because there are so few observations of this species, there is a high degree of uncertainty regarding the size of its range. This species has not been observed since 2007, although there has not likely been sufficient recent search effort to detect the species. Within the range of the species, effects from ongoing climate change and severe drought have been observed, as well as impacts from urbanization and exposure to pesticides. These threats may be acting on the species at local levels. More research is needed about the range extent, population trends, habitat and ecology, and threats to this species. As such, it is assessed as Data Deficient for now.

Because there are limited records of this species, little is known about its habitat and ecology. Few records have associated floral host information, therefore the dietary breadth of Andrena papagorum is unknown. It has been observed collecting pollen from the genus Salix (Salicaceae) (LaBerge and Ribble 1972). Records of this species come from shrublands, evergreen forest, and agricultural lands. 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 (J. H. Cane 1981) that serves to both isolate the provision from pathogens in the surrounding soil and to regulate water uptake from the soil atmosphere (James H. 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 August, with most observations from May (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

Since 2000, the Southwest U.S. has seen the worst drought in 1200 years ((A. P. 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 (Hung et al. 2021). Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena papagorum 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 (N. M. 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), U.S. Forest Service, 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 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 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.