Andrena citrinihirta

Justification:
Andnena citrinihirta is a solitary bee that occurs in the western United States, from southern Oregon south to the Los Angeles, California vicinity. Using all records of the species, the extent of occurrence is 340,097 km2. The species has not been observed since 1975, therefore, it is unclear if the species persists throughout its entire known range. The species has been recorded foraging from two genera from the plant family Asteraceae, although there is not enough information to determine the full dietary breadth of this species. Andrena citrinihirta has been observed in grasslands, shrublands, and urban areas. Across the range of the species, impacts from climate change, drought and exposure to pesticides have been observed. These threats may be acting on the species at local levels. More information is needed to determine if this species is extant across its range, to better understand its life history, and to determine the degree to which threats are acting on the species. SEARCH EFFORT SENTENCE. For now, the species is assessed as Data Deficient.

Food habits comment: Andrena cirtrinihirta has only been recorded foraging from the genera Heterotheca and Solidago (Asteraceae) (Donovan 1977). The dietary breadth of this species has not been directly studied, but it is possible that this species is a dietary specialist. Habitat comment: This species has been recorded in grasslands, shrublands, urban areas at elevations below 1,600 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 September and October (Chesshire et al. 2023; Donovan 1977). Adults are assumed to emerge annually (Danforth et al. 2019).

Threat comments: Specific threats to this species have not been investigated. Andrena citrinihirta may be threatened by severe drought in parts of its range. 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 may be impacted by agricultural intensification, including high exposure to pesticides where it occurs in California’s Central Valley. The Central Valley of California is one of the most intensively farmed regions in the U.S.(Katibah 1984). An estimated 71% of the Central California Valley ecoregion is devoted to agriculture (Soulard and Wilson 2015). This species may be impacted by high exposure to pesticides where it occurs in the Central Valley. This region has some of the nation’s highest pesticide inputs, which can be detected in non-target plant species, sometimes in insect-lethal concentrations, across all land use types (Halsch et al. 2020). Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena citrinihirta 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: Timing: Scope: Severity: Impact Score: 1. Residential & commercial development -> 1.1. Housing & urban areas Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 1. Residential & commercial development -> 1.2. Commercial & industrial areas Timing: Ongoing Scope: Minority (<50%) Severity: Slow, significant declines 2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.3. Agro-industry farming 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: Minority (<50%) 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: Observations of this species are known from National Park Service and 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): 3-4-2025 Assessors names (use * to indicate primary assessor, typically the participant with most experience/knowledge of the species): Saff 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: Andnena citrinihirta is a solitary bee that occurs in the western United States, from southern Oregon south to the Los Angeles, California vicinity. Using all records of the species, the extent of occurrence is 340,097 km2. The species has not been observed since 1975, therefore, it is unclear if the species persists throughout its entire known range. The species has been recorded foraging from two genera from the plant family Asteraceae, although there is not enough information to determine the full dietary breadth of this species. Andrena citrinihirta has been observed in grasslands, shrublands, and urban areas. Across the range of the species, impacts from climate change, drought and exposure to pesticides have been observed. These threats may be acting on the species at local levels. More information is needed to determine if this species is extant across its range, to better understand its life history, and to determine the degree to which threats are acting on the species. SEARCH EFFORT SENTENCE. For now, the species is assessed as Data Deficient. Rank reasons This species is a solitary bee that occurs in the western United States, from southern Oregon south to the Los Angeles, California vicinity. Using all verified records of the species, the range extent is 340,097 km2. This species occurs in grasslands, shrublands, and urban areas. It has been recorded foraging from two genera from the plant family Asteraceae, but there is not enough information at this time to determine if this species is a dietary specialist. Across the range of the species, impacts from climate change and pesticide exposure have been observed. These threats may be acting on the species at local levels. This species has not been observed since 1975. Therefore it is unclear if the species is still extant across its known range. Therefore, this species is likely/unlikely 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 (A) 1. Estimated Number of Element Occurrences Comments: This species has not been observed since 1975, therefore, there are no element occurrences of this species from the recent era. 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: This species may be a dietary specialist, using pollen from the plant family Asteraceae, which likely restricts its distribution and phenology. However there is not enough information available at this time to determine 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, Suburban/Orchard 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. Donovan, B. 1977. “Revision of North American Bees of the Subgenus Cnemidandrena (Hymenoptera: Andrenidae).” https://doi.org/10.5555/19770206080. 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. Halsch, Christopher A., Aimee Code, Sarah M. Hoyle, James A. Fordyce, Nicolas Baert, and Matthew L. Forister. 2020. “Pesticide Contamination of Milkweeds Across the Agricultural, Urban, and Open Spaces of Low-Elevation Northern California.” Frontiers in Ecology and Evolution 8:162. 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. Katibah, Edwin F. 1984. “A Brief History of Riparian Forests in the Central Valley of California[l].” Press, c 1:984. 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. Soulard, Christopher E., and Tamara S. Wilson. 2015. “Recent Land-Use/land-Cover Change in the Central California Valley.” Journal of Land Use Science 10 (1): 59–80. 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 National Park Service and 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.