Andrena aculeata

Justification:
Andrena aculeata is a solitary bee that occurs in the interior Pacific Northwest region of the United States and Canada. Using all available records, the extent of occurrence (EOO) of this species is 282,330 km2, and the area of occurrence (AOO) may be as small as 28 km2, although limited surveys for bees generally contributed to a high degree of uncertainty with regard to the AOO. This species may occur in as few as seven locations, where it is threatened by agricultural conversion, wildfire, and exposure to pesticides.[b] There are very few records of this species overall, and has only been observed once since 1964, at some point between 2000 and 2002. Little is known about the habitat preferences, dietary breadth, or nest biology of this species. Within its range, impacts from agricultural conversion have been observed and may be acting on this species. More information is needed about the population trend and biology of this species. of the limited biology information, limited records, and lack of records from the last two decades. Because this species has a restricted AOO, coupled with fewer than 10 locations, with continuing decline in habitat where it occurs, this species is ranked as Vulnerable for now. Unidentified museum material should be examined for the presence of this species, and surveys specifically targeting this species should be conducted to verify its status.

There is limited information available about the habitat and ecology of Andrena aculeata. It has been observed in coniferous forests, subalpine zones, and agricultural areas in the Columbia Plateau and the Western Cordillera of the United States. The dietary breadth of this species has not been described, but has been recorded visiting the invasive starthistle Centaurea solstitialis. 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 May through August (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

1.6 Conservation actions 3. Monitoring -> 3.1. Population trends 3.4. Habitat trends Assessment Date of assessment (month-day-year): 2-26-2024 Assessors names (use * to indicate primary assessor, typically the participant with most experience/knowledge of the species): Saf Killingsworth Reviewer(s): Contributors(s): For a full list of the 162 institutions that contributed to the Chesshire et al. dataset, please see Chesshire et al. 2023, S1. Facilitator(s) and compiler(s): Paige R. Chesshire, Erica E. Fischer, Nicolas J. Dowdy, Terry L. Griswold, Alice C. Hughes, Michael C. Orr, John S. Ascher, Laura M. Guzman, Keng-Lou James Hung, Neil S. Cobb and Lindsie M. McCabe Red List Category and Criteria: Data Deficient Justification: Andrena aculeata is a solitary bee that occurs in the interior Pacific Northwest region of the United States and Canada. Using all available records, the extent of occurrence (EOO) of this species is 282,330 km2, and the area of occurrence (AOO) may be as small as 28 km2, although limited surveys for bees generally contributed to a high degree of uncertainty with regard to the AOO. This species may occur in as few as seven locations, where it is threatened by agricultural conversion, wildfire, and exposure to pesticides.[b] There are very few records of this species overall, and has only been observed once since 1964, at some point between 2000 and 2002. Little is known about the habitat preferences, dietary breadth, or nest biology of this species. Within its range, impacts from agricultural conversion have been observed and may be acting on this species. More information is needed about the population trend and biology of this species. of the limited biology information, limited records, and lack of records from the last two decades. Because this species has a restricted AOO, coupled with fewer than 10 locations, with continuing decline in habitat where it occurs, this species is ranked as Vulnerable for now. Unidentified museum material should be examined for the presence of this species, and surveys specifically targeting this species should be conducted to verify its status. NatureServe Specific Text: For Rank Calculator: 1. Element occurrences (using separation distance of 5,000 m): 7 (B) 1. Estimated Number of Element Occurrences Comments: There are limited element occurrences overall, and none since 2002. The most recent record comes from northeast Oregon. 2. Population size: Unknown 3. Viability/Ecological integrity (choose one) 1. Number of occurrences with good viability/ecological integrity: Unknown 2. Percent of area occupied (For Species with Known AOO): N/A 4. Environmental Specificity: B. Narrow. Specialist or community with key requirements common. 1. Environmental specificity comments: Unknown. 5. Intrinsic Vulnerability: B. Moderately vulnerable 1. Intrinsic vulnerability comments: 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). 6. Trend 1. Short Term Trend: Unknown 2. Comments: Abundance estimates and population trends are not known for this species. 3. Long Term Trend: Unknown 4. Comments: Abundance estimates and population trends are not known for this species. For Biotics Global Element Characterization: 1. Habitat Forest/Woodland, Cropland/Hedgerow Literature References: Brown, Mark J. F., and Robert J. Paxton. 2009. “The Conservation of Bees: A Global Perspective.” Apidologie 40 (3): 410–16. Cane, James H. 1981. “Dufour’s Gland Secretion in the Cell Linings of Bees (Hymenoptera: Apoidea).” Journal of Chemical Ecology 7 (2): 403–10. Cane, and Love. 2021. “Hygroscopic Larval Provisions of Bees Absorb Soil Water Vapor and Release Liquefied Nutrients.” Apidologie 52 (6): 1002–16. Chesshire, Paige R., Erica E. Fischer, Nicolas J. Dowdy, Terry L. Griswold, Alice C. Hughes, Michael C. Orr, John S. Ascher, et al. 2023. “Completeness Analysis for over 3000 United States Bee Species Identifies Persistent Data Gap.” Ecography, February. https://doi.org/10.1111/ecog.06584. Danforth, Bryan N., Robert L. Minckley, John L. Neff, and Frances Fawcett. 2019. The Solitary Bees: Biology, Evolution, Conservation. Princeton University Press. Grab, Heather, Michael G. Branstetter, Nolan Amon, Katherine R. Urban-Mead, Mia G. Park, Jason Gibbs, Eleanor J. Blitzer, Katja Poveda, Greg Loeb, and Bryan N. Danforth. 2019. “Agriculturally Dominated Landscapes Reduce Bee Phylogenetic Diversity and Pollination Services.” Science 363 (6424): 282–84. LaBerge, Wallace E. 1980. “A Revision of the Bees of the Genus Andrena of the Western Hemisphere. Part X. Subgenus Andrena.” Transactions of the American Entomological Society 106 (4): 395–525. Mciver, James, Robbin Thorp, and Karen Erickson. 2009. “Pollinators of the Invasive Plant, Yellow Starthistle (Centaurea Solstitialis), in North‐eastern Oregon, USA.” Weed Biology and Management 9 (2): 137–45. Michener, Charles Duncan. 2007. The Bees of the World. Vol. 1. JHU Press. Potts, Simon G., Jacobus C. Biesmeijer, Claire Kremen, Peter Neumann, Oliver Schweiger, and William E. Kunin. 2010. “Global Pollinator Declines: Trends, Impacts and Drivers.” Trends in Ecology & Evolution 25 (6): 345–53. Raven, Peter H., and David L. Wagner. 2021. “Agricultural Intensification and Climate Change Are Rapidly Decreasing Insect Biodiversity.” Proceedings of the National Academy of Sciences of the United States of America 118 (2). https://doi.org/10.1073/pnas.2002548117. Rousseau, Josée S., S. Hollis Woodard, Sarina Jepsen, Brianne Du Clos, Alison Johnston, Bryan N. Danforth, and Amanda D. Rodewald. 2024. “Advancing Bee Conservation in the US: Gaps and Opportunities in Data Collection and Reporting.” Frontiers in Ecology and Evolution 12. https://doi.org/10.3389/fevo.2024.1346795. Williams, N. M., Elizabeth E. Crone, T’ai H. Roulston, Robert L. Minckley, Laurence Packer, and Simon G. Potts. 2010. “Ecological and Life-History Traits Predict Bee Species Responses to Environmental Disturbances.” Biological Conservation 143 (10): 2280–91. Wojcik, Victoria A., Lora A. Morandin, Laurie Davies Adams, and Kelly E. Rourke. 2018. “Floral Resource Competition Between Honey Bees and Wild Bees: Is There Clear Evidence and Can We Guide Management and Conservation?” Environmental Entomology 47 (4): 822–33. [a]needs work [b]needs work

Conservation needs No known conservation actions are in place for this species. Observations of this species are known from 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.