Andrena argemonis

Justification:
The Prickly-poppy Mining Bee (Andrena argemonis) is a solitary bee species that occurs in the deserts and mountains of the western United States and throughout much of Mexico. Using all observations, the extent of occurrence is 2,533,212 km2. Since 2013, this species has been observed in several widely dispersed localities in the United States portion of its range. It has not been observed in this same time period in Mexico, although this is likely related to limited sampling effort there. The species occurs in deserts, grasslands, shrublands, mixed and coniferous forest, as well as agricultural and urban areas. The Prickly-poppy Mining bee appears to be a dietary generalist, although exhibits a strong preference for Prickly-poppy (Papaveraceae: Argemone). Across the range of the species, impacts from climate change, urbanization, and exposure to pesticides have been observed. However, because the species is widespread and occurs in many different habitat types, it is unlikely that it is threatened with extinction at this time. As such, it is evaluated as Least Concern.

Andrena argemonis is one of the largest Andrena species. It appears to be a dietary generalist, but shows a strong preference for the plants from the genus Argemone (Papaveraceae) (Laberge 1969). It has been recorded in deserts, grasslands, shrublands, evergreen and mixed forest, urban areas, and agricultural 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 June through September, with most records from July and August (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 argemonis 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). This species exhibits a strong dietary preference, which may be linked to higher risk of extinction due to reduced host plant availability, especially under climate change scenarios (Roberts et al. 2011) and reduced effective population sizes (Packer et al. 2005). 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), United States Forest Service, and Mexican state and federally protected 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.

The revision of this species (Laberge 1969) notes that there appears to be a pattern of geographical variation in thoracic hair types between northern and southern specimens. However, this trait does not correspond with other structural characters. There are also very few specimens known from the region where intergrades are expected to occur. Based on the evidence at the time of writing the revision, the author determined that this variation represented one species, with perhaps sufficient evidence to recognize a southern race.