Genus species

Justification:
Andrena subrubicunda is a solitary bee known from just two localities and approximately 40 observations, last observed in 1937. Records were collected in southern California, United States. Because the species is only known from two localities, estimating an extent of occurrence is not possible. It is not clear if this species is still extant. There is no available information about the habitat or ecology of the species. Specific threats to this species have not been identified. It may be subject to threats acting on other bee species, like climate change, exposure to pesticides, and habitat loss. More information is needed to determine if this species is extant, and to understand its ecology. Because the species has only been recorded in two localities, and has not been observed in nearly 90 years, it is ranked as Data Deficient for now.

Food habits comment: Genus species is a dietary generalist specialist, and collects pollen from specific wide variety of plants including xxx. Habitat comment: This species has been recorded in XXX, between XX and XX m. Reproduction comment: 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). Phenology comment: Records of this species come from months (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

Threat comments: IF OCCURS IN SW: 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). Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena SPECIES 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 is a dietary specialist, which has been 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). Threats Threats: Timing: Scope: Severity: Impact Score: Timing: Past, Unlikely to Return Ongoing Future Unknown Past, unlikely to return Scope: Unknown Whole: >90% Majority: 50 - 90% Minority <50% Severity: Very Rapid Declines Rapid Declines Slow, significant declines Causing/Could cause fluctuations Negligible declines no decline Unknown 1. Residential & commercial development -> 1.1. Housing & urban areas 1. Residential & commercial development -> 1.2. Commercial & industrial areas 2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.3. Agro-industry farming 7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.1.Increase in fire frequency/intensity 7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.2. Suppression in fire frequency/intensity 8. Invasive and other problematic species, genes, and diseases -> 8.1 Invasive non-native/alien species/diseases -> 8.1.2. Named species 9. Pollution -> 9.3 Agricultural and forestry effluents -> 9.3.3 Herbicides and Pesticides 11. Climate change & severe weather -> 11.1. Habitat shifting & alteration 11. Climate change & severe weather -> 11.2.Droughts 11. Climate change & severe weather -> 11.3.Temperature extremes Conservation Actions Conservation needs No known conservation actions are in place for this species. Protected/Managed area comment: Observations of this species are known from Bureau of Land Management (BLM) land, but this does not confer any specific protections to the species. Management comment: 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. Conservation Actions Needed 1. Land/water protection -> 1.2. Resource & habitat protection 2. Land/water management -> 2.3. Habitat & natural process restoration 4. Education & awareness -> 4.3. Awareness & communications 5. Law & policy -> 5.2. Policies and regulations Research needs Research need comment: More information is needed about the population status, population trend, existing threats, range limits, habitat, and ecology of this species. Surveys targeting this species are needed throughout its range to determine its persistence throughout its historic range. Research Needed 1. Research -> 1.2. Population size, distribution & trends 1.3. Life History and Ecology 1.5. Threats 1.6 Conservation actions 3. Monitoring -> 3.1. Population trends 3.4. Habitat trends Assessment Date of assessment (month-day-year): Assessors names (use * to indicate primary assessor, typically the participant with most experience/knowledge of the species): Reviewer(s): Contributors(s): For assessments using Winfree data: Faye Benjamin, Bethanne Bruninga-Socolar, Tina Harrison, Molly MacLeod, Michael Roswell, Rachael Winfree For assessments using Vandame data: Philippe Sago, Jorge Mérida, Oscar Martinez, Rémy Vandame, and Carlos Cultid For assessments using Hung data: Keng-Lou James Hung, John S. Ascher, Doug Yanega, Henry J. Cen, Adrienne Lee, David A. Holway 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: Rank/Criteria Justification: Andrena subrubicunda is a solitary bee known from just two localities and approximately 40 observations, last observed in 1937. Records were collected in southern California, United States. Because the species is only known from two localities, estimating an extent of occurrence is not possible. It is not clear if this species is still extant. There is no available information about the habitat or ecology of the species. Specific threats to this species have not been identified. It may be subject to threats acting on other bee species, like climate change, exposure to pesticides, and habitat loss. More information is needed to determine if this species is extant, and to understand its ecology. Because the species has only been recorded in two localities, and has not been observed in nearly 90 years, it is ranked as Data Deficient for now. Rank reasons This species is a solitary bee known from just two localities and approximately 40 observations, last observed in 1937. These records were collected in southern California, United States. Because the species is only known from two localities, estimating a range extent is not possible. It is not clear if this species is still extant. There is no available information about the habitat or ecology of the species. Specific threats to this species have not been identified. It may be subject to threats acting on other bee species, like climate change, exposure to pesticides, and habitat loss. More information is needed to determine if this species is extant, and to understand its ecology. Because the species has only been in two localities, and has not been observed in nearly 90 years, it is unranked at this time. NatureServe Specific Text (NOT OTHERWISE INCLUDED IN ABOVE TEXT): For Rank Calculator: 1. Element occurrences (using separation distance of 5,000 m): 0 1. Estimated Number of Element Occurrences Comments:There are no element occurrences of this species from the last 30 years (since 1995). Overall this species is only known from two localities using a 5 km separation distance. 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: Unknown 1. Environmental specificity comments: There is not enough information about this species to understand its environmental specificity, although it may have specific habitat requirements that are not yet understood. 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 Unknown 2. Food Habits 1. Adult: nectarivore 2. Immature: nectarivore 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., and Byron G. Love. 2021. “Hygroscopic Larval Provisions of Bees Absorb Soil Water Vapor and Release Liquefied Nutrients.” Apidologie 52 (6): 1002–16. Cane, J. H. 1981. “Dufour’s Gland Secretion in the Cell Linings of Bees (Hymenoptera: Apoidea).” Journal of Chemical Ecology 7 (2): 403–10. 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. Hung, Keng-Lou James, Sara S. Sandoval, John S. Ascher, and David A. Holway. 2021. “Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot.” Insects 12 (2). https://doi.org/10.3390/insects12020135. Michener, Charles Duncan. 2007. The Bees of the World. Vol. 1. JHU Press. Minckley, Robert L., T’ai H. Roulston, and Neal M. Williams. 2013. “Resource Assurance Predicts Specialist and Generalist Bee Activity in Drought.” Proceedings. Biological Sciences / The Royal Society 280 (1759): 20122703. Packer, Laurence, Amro Zayed, Jennifer C. Grixti, Luisa Ruz, Robin E. Owen, Felipe Vivallo, and Haroldo Toro. 2005. “Conservation Genetics of Potentially Endangered Mutualisms: Reduced Levels of Genetic Variation in Specialist versus Generalist Bees.” Conservation Biology: The Journal of the Society for Conservation Biology 19 (1): 195–202. 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. Roberts, Stuart, Simon Potts, Koos Biesmeijer, Michael Kuhlmann, William Kunin, and Ralf Ohlemüller. 2011. “Assessing Continental-Scale Risks for Generalist and Specialist Pollinating Bee Species under Climate Change.” BioRisk : Biodiversity & Ecosystem Risk Assessment 6 (December): 1–18. 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, A. Park, B. I. Cook, and S. E. Smerdon. 2022. “Rapid Intensification of the Emerging Southwestern North American Megadrought in 2020–2021.” Nature Climate Change 12 (3): 232–34. 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. Wilson Rankin, Erin E., Sarah K. Barney, and Giselle E. Lozano. 2020. “Reduced Water Negatively Impacts Social Bee Survival and Productivity Via Shifts in Floral Nutrition.” Journal of Insect Science 20 (5). https://doi.org/10.1093/jisesa/ieaa114. 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.

Conservation needs No known conservation actions are in place for this species. Protected/Managed area comment: Observations of this species are known from Bureau of Land Management (BLM) land, but this does not confer any specific protections to the species. Management comment: 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.

Research need comment: More information is needed about the population status, population trend, existing threats, range limits, habitat, and ecology of this species. Surveys targeting this species are needed throughout its range to determine its persistence throughout its historic range.

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