Andrena coactipostica

Justification:
Andrena coactipostica is a solitary bee species that occurs in the southern half of California, United States. Using all observations, the extent of occurrence (EOO) for the species is 46,336 km2. The species has not been observed anywhere in its range since 1969. It is unclear if the species is still extant throughout its known range. It is known from approximately 90 observations, most of which come from one very small area within the species range. This area has seen considerable development since these observations were made, and these localities may no longer host the species. The species is known from 11 localities, which may constitute 11 locations if threats act independently at each locality. Across the range of the species, impacts from climate change, habitat degradation and loss, and exposure to pesticides have been observed. These threats may be acting on the species at local levels. Because the species has not been recently observed, and occurs in a relatively small area that has seen high habitat loss and degradation, and is known from few locations, it is likely threatened with extinction at this time. Because the extent of occurrence and number of locations do not meet the criteria to be considered Vulnerable under criterion B, it is assessed as Near Threatened for now.

Food habits comment: Andrena coactipostica apparently prefers pollen from the plant families Papaveraceae and Boraginaceae, although there is not enough information about the dietary habits of this species to determine if this species is a dietary specialist (Laberge 1969). Habitat comment: This species has been recorded in grasslands, shrublands, and agricultural areas between 82 and 1180 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 February through May (Chesshire et al. 2023; Laberge 1969). Adults are assumed to emerge annually (Danforth et al. 2019).

Threat comments: 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). This species occurs in California coastal sage scrub habitat, one of California's most threatened vegetation types, which is globally imperiled (NatureServe 2024). This habitat is highly threatened by modification, fragmentation, and loss due to urban and suburban growth. Nearly half of California’s residents live in the coastal California counties where this habitat occurs, which is less than 10% of the state’s land area (Riordan and Rundel 2013). Less than 20% of this habitat remains (Davis, Stine, and Stoms 1994), and the existing fragments are considered some of most valuable real estate in California. This contributes to considerable development pressure on remaining fragments, and their high real estate value makes their conservation costly. Coastal sage scrub has also been modified significantly in the past 100 years due to exotic annual grass invasion, which has been facilitated by increased wildfire frequency (Minnich and Dezzani 1998; Talluto and Suding 2008). These factors also contribute to a feedback where increased grass cover increases fire frequency, leading to grassland conversion. This habitat conversion may limit the availability of host plants used by Andrena coactipostica and alter other abiotic factors important for this species. Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena coactipostica 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 may be 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: 1. Residential & commercial development -> 1.1. Housing & urban areas Timing: Ongoing Scope: Majority (50-90%) Severity: Slow, significant declines 1. Residential & commercial development -> 1.2. Commercial & industrial areas Timing: Ongoing Scope: Majority (50-90%) Severity: Slow, significant declines 7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.1.Increase in fire frequency/intensity Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 8. Invasive and other problematic species, genes, and diseases -> 8.1 Invasive non-native/alien species/diseases -> 8.1.2. Named species Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 9. Pollution -> 9.3 Agricultural and forestry effluents -> 9.3.3 Herbicides and Pesticides Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 11. Climate change & severe weather -> 11.1. Habitat shifting & alteration Timing: Ongoing Scope: Majority (50-90%) Severity: Slow, significant declines 11. Climate change & severe weather -> 11.2.Droughts Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 11. Climate change & severe weather -> 11.3.Temperature extremes Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines Conservation Actions Conservation needs No known conservation actions are in place for this species. Protected/Managed area comment: This is known from U.S. Forest Service land (San Bernardino National Forest), 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 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: Near Threatened Justification: Andrena coactipostica is a solitary bee species that occurs in the southern half of California, United States. Using all observations, the extent of occurrence (EOO) for the species is 46,336 km2. The species has not been observed anywhere in its range since 1969. It is unclear if the species is still extant throughout its known range. It is known from approximately 90 observations, most of which come from one very small area within the species range. This area has seen considerable development since these observations were made, and these localities may no longer host the species. The species is known from 11 localities, which may constitute 11 locations if threats act independently at each locality. Across the range of the species, impacts from climate change, habitat degradation and loss, and exposure to pesticides have been observed. These threats may be acting on the species at local levels. Because the species has not been recently observed, and occurs in a relatively small area that has seen high habitat loss and degradation, and is known from few locations, it is likely threatened with extinction at this time. Because the extent of occurrence and number of locations do not meet the criteria to be considered Vulnerable under criterion B, it is assessed as Near Threatened for now. Rank reasons This species is a solitary bee that occurs in Southern California, United States. Using all verified records of the species, the range extent is 46,336 km2. This species occurs in grasslands, shrublands, and agricultural areas. It appears to exhibit a dietary preference for plants from the families Papaveraceae and Boraginaceae, although there is not enough data to determine if this species is a dietary specialist. Across the range of the species, impacts from climate change, pesticide exposure, and urbanization have been observed. These threats may be acting on the species at local levels. Because the species is known from a relatively small area with considerable habitat loss due to development, is known from few localities overall, and has not been observed since 1969, this species is considered to be threatened with extinction 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: Using all records from the last 30 years (since 1995), this species is known from zero occurrences 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: B. Narrow. Specialist or community with key requirements common. 1. Environmental specificity comments: This species exhibits a restricted dietary preference for species in the families Papaveraceae and Boraginaceae, although it is not certain if this species is a dietary specialist. 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 Shrubland/chaparral, Grassland/Herbaceous, Cropland/Hedgerow 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. Davis, Frank W., Peter A. Stine, and David M. Stoms. 1994. “Distribution and Conservation Status of Coastal Sage Scrub in Southwestern California.” Journal of Vegetation Science: Official Organ of the International Association for Vegetation Science 5 (5): 743–56. 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. Laberge, Wallace E. 1969. “A Revision of the Bees of the Genus Andrena of the Western Hemisphere. Part II. Plastandrena, Aporandrena, Charitandrena.” Transactions of the American Entomological Society 95 (1): 1–47. 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. Minnich, R., and R. Dezzani. 1998. “Historical Decline of Coastal Sage Scrub in the Riverside-Perris Plain, California.” https://www.academia.edu/download/80941433/p0366-p0391.pdf. 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. Riordan, Erin C., and Philip W. Rundel. 2013. “The Future of California Sage Scrub in an Era of Increasing Urbanization and Global Climate Change.” Fremontia 41:2–7. 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. Talluto, Matt V., and Katharine N. Suding. 2008. “Historical Change in Coastal Sage Scrub in Southern California, USA in Relation to Fire Frequency and Air Pollution.” Landscape Ecology 23 (7): 803–15. 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: This is known from U.S. Forest Service land (San Bernardino National Forest), 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.