California Native Bees

Species counts

How many bee species live in California?

California holds a large share of the country's bee diversity. Counts vary a little by source because many species are still undescribed.

1. About 1,600 of the roughly 4,000 bee species known in the United States have been recorded in California, according to UC researchers writing in 2009. (Source: Frankie et al., California Agriculture 63(3), 2009)
2. The USDA Forest Service states there are 4,000 native bee species in the United States. (Source: USDA Forest Service and Pollinator Partnership, Bee Basics (FS-960), 2011 reprint)
3. The US Geological Survey says more than 4,000 native bee species inhabit the United States, and that several are declining. (Source: USGS, image caption, More than 4,000 native bee species inhabit the United States)
4. The Xerces Society gives a lower figure of over 3,600 wild bee species in the United States. (Source: Xerces Society, State of the Bees web page)
5. About 20,000 bee species have been named worldwide, with an estimated 20,000 more still to be described. (Source: Sam Droege, USGS Bee Inventory and Monitoring Lab, presentation hosted by USDA)
6. Roughly 400 bee species in the United States are thought to be undescribed. (Source: Sam Droege, USGS Bee Inventory and Monitoring Lab, presentation hosted by USDA)
7. More than 260 bumble bee (Bombus) species exist worldwide, with around 25 occurring in California. (Source: California Department of Fish and Wildlife, candidate bumble bee conservation considerations, 2026)
8. There are about 50 species of North American bumble bees. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
9. California is home to three large carpenter bee species: Xylocopa varipuncta, X. californica and X. tabaniformis orpifex. (Source: UC Davis Laidlaw Honey Bee Research Facility, native bees archive)

US totals differ by source: USDA and USGS say about 4,000 native species, while the Xerces Society says over 3,600. The gap reflects which species are counted as described and native. The 1,600 California figure dates from 2009 and is a count of recorded species, not a final total.

Who is who

The main groups of native bees in Southern California

Most native bees in a Southern California yard fall into a handful of groups. Sizes below come from western US extension guides.

1. The valley carpenter bee (Xylocopa varipuncta) is about an inch long; the female is solid black and the male, called the teddy bear bee, is a green-eyed blond. (Source: UC ANR Bug Squad blog, 2017)
2. A 2020 taxonomic paper placed Xylocopa varipuncta into synonymy with the older name Xylocopa sonorina, so the valley carpenter bee may appear under either name. (Source: Sheffield, Heron and Musetti, Biodiversity Data Journal 8: e49918, 2020)
3. Xylocopa tabaniformis orpifex is the smallest of California's three large carpenter bees, about half the size of the other two. (Source: UC Davis Laidlaw Honey Bee Research Facility, native bees archive)
4. Large carpenter bee females are very large, about 3/4 inch, while small carpenter bees are typically about 1/4 inch. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
5. Most bumble bee species are large, about 3/4 to 1 inch. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
6. Sweat bees are small, 3 to 12 mm, and some are vividly metallic green and yellow. (Source: University of Arizona, Arizona Bee Identification Guide)
7. Andrenid mining bees are all ground nesters and are among the earliest bees to emerge in spring. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
8. Andrena mining bees measure 6 to 15 mm; the related Perdita bees are only 2 to 7 mm. (Source: University of Arizona, Arizona Bee Identification Guide)
9. Leafcutter bees are small to medium, about 1/4 to 1/2 inch, and line their nest cells with circular leaf pieces. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
10. Mason bees range from about 1/4 to 3/4 inch; some use mud to build walls between nest cells. (Source: Utah State University Extension; USDA Forest Service, Bee Basics)
11. The blue orchard bee, Osmia lignaria, is a native mason bee of the western United States. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
12. USDA researchers estimated that 10 square yards of mixed wildflowers could support 400 blue orchard bee mothers, whose offspring could pollinate 3 acres of almonds the next year. (Source: USDA Agricultural Research Service, Agricultural Research magazine, August 2010)
13. Squash bees begin work at or before dawn and often nest underground beneath the squash plants they pollinate. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
14. In a Central Valley squash field, more squash bees emerged per cage from untilled plots than from deep-tilled plots (11 vs 8), in a 20-plot study. (Source: Ullmann, Meisner and Williams, Agriculture, Ecosystems and Environment 232, 2016)
15. California digger bees (Anthophora bomboides stanfordiana) dig nests into moistened sandstone cliffs at Bodega Head, leaving dense clusters of mud entrance turrets. (Source: UC ANR, Bug Squad)
16. Cuckoo bees do not gather pollen and have lost their pollen baskets and much of their hair; they lay eggs in other bees' nests. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
17. At least 10% of Arizona's bee species are parasitic cuckoo bees. (Source: University of Arizona, Arizona Bee Identification Guide)

Size ranges come from Utah and Arizona extension guides and may differ slightly for California populations. Where a season is not given, the cited sources did not state one for the group. The sting column states only what the sources say: only females can sting (UC IPM); sources did not give a sting frequency for leafcutter, mason, squash or cuckoo bees.

Nests

Where native bees nest, and why most live alone

Unlike honey bees, most native bees are solitary. Each female builds and stocks her own small nest.

1. About 70% of US native bee species dig their nests underground. (Source: Xerces Society, USDA National Agroforestry Center AF Note 34, 2007)
2. About 30% of US native bee species are solitary wood-nesters that build nests inside hollow tunnels. (Source: Xerces Society, USDA National Agroforestry Center AF Note 34, 2007)
3. Standing dead trees are important nesting habitat for 30% of US native bees. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
4. Only about 45 US bee species are social bumble bees. (Source: Xerces Society, USDA National Agroforestry Center AF Note 34, 2007)
5. Bumble bees keep an annual colony: an overwintering queen starts it in spring, and only new queens survive to the next year. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
6. Bumble bee queens do not dig their own nests; western bumble bees nest in underground cavities such as abandoned rodent burrows. (Source: California Department of Fish and Wildlife, 2026)
7. Several confirmed Crotch's bumble bee nests were found underground in abandoned ground squirrel and gopher burrows. (Source: California Department of Fish and Wildlife, 2026)
8. Some species of sweat bees can be considered truly social, according to the USDA Forest Service. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
9. Ground-nesting bees are solitary but often nest close together in good soil, which is not the same as a colony. (Source: Utah State University Extension, Solitary/Ground Bees)
10. Carpenter bee females use powerful mandibles to excavate wide tunnel systems in wood. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
11. A honey bee colony, by contrast, can reach 30,000 or more individuals. (Source: University of Arizona, Arizona Bee Identification Guide)

The 70% and 30% figures are national estimates, not California-specific counts.

Stings

Do California native bees sting?

Native bees can sting, but they rarely do. Most have no colony and no honey store to defend.

1. Only female bees and wasps can sting, because the stinger is a modified egg-laying organ. (Source: UC IPM, Pest Notes: Bee and Wasp Stings, Publication 7449, 2011)
2. Male carpenter bees cannot sting. (Source: USDA Forest Service, Bee Basics, 2011 reprint; UC ANR Bug Squad, 2017)
3. Some andrenid mining bees cannot sting people because their stingers are too small and weak to penetrate skin. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
4. Ground-nesting bees can sting, but the sting is mild and their nests pose minimal health risk. (Source: Utah State University Extension, Solitary/Ground Bees)
5. NC State entomologists report that ground-nesting bees do not generally sting and are active for about 3 to 4 weeks. (Source: NC State Extension, 2014, updated 2024)
6. A honey bee's stinger is barbed and usually stays in the skin, so it should be removed quickly. (Source: UC IPM, Pest Notes: Bee and Wasp Stings, 2011)
7. Bees are unlikely to sting while gathering nectar and pollen, but will sting in defense if provoked; stings often happen when nests of social insects are disturbed. (Source: UC IPM, Pest Notes: Bee and Wasp Stings, 2011)

This page is not medical advice. Anyone with signs of a severe allergic reaction to a sting should seek emergency care.

Introduced

Honey bees are not native to California

The honey bee is the bee most people picture, but it came from Europe. It is the only bee here that lives in large, permanent colonies.

1. European colonists introduced the honey bee to America, in what is now Virginia, in 1622. (Source: UC ANR Bug Squad blog, 2021)
2. Christopher A. Shelton brought the first honey bees successfully introduced to California to Rancho Potrero de Santa Clara in San Jose in early March 1853. (Source: California Office of Historic Preservation, Historical Landmark No. 945)
3. Shelton bought 12 hives in Aspinwall, Panama; only enough bees survived the trip to fill one hive. (Source: California Office of Historic Preservation, Historical Landmark No. 945)
4. The USDA Forest Service describes honey bees as brought to North America by European colonists about 400 years ago. (Source: USDA Forest Service, Bee Basics, 2011 reprint)
5. Of 229 bee species recorded in 10 California cities from 2005 to 2011, only 5 were non-native: four Megachilidae and the honey bee. (Source: Frankie et al., Journal of Pollination Ecology 25(3), 2019)
6. In Albany and Berkeley garden surveys, 78 of 82 bee species recorded were native to California. (Source: Frankie et al., California Agriculture, 2009)

City gardens

How many native bees live in California city gardens?

The UC Berkeley Urban Bee Lab, led by Gordon Frankie with UC Davis bee expert Robbin Thorp, has surveyed bees in California cities since the 2000s.

1. A 2005-2007 UC survey of bees on ornamental plants in seven California cities found the most species in Berkeley (82) and the fewest in Santa Cruz (41). (Source: Frankie et al., California Agriculture 63(3), 2009)
2. La Cañada Flintridge, near Pasadena, recorded 73 bee species in 28 genera, the most of the three Southern California cities in the 2009 study. (Source: Frankie et al., California Agriculture 63(3), 2009)
3. The 2005-2007 survey logged 2,485 bee counts on 31 target plants, with 400 person-days of effort in the north and 220 in the south. (Source: Frankie et al., California Agriculture 63(3), 2009)
4. UC Berkeley researchers recorded 84 bee species in Berkeley gardens and suspected the city held 95 to 100 species. (Source: UC Berkeley, Berkeleyan news story, 2009)
5. Of about 1,000 garden plants the Berkeley team monitored, 130 were attractive to bees and 70 more moderately attractive. (Source: UC Berkeley, Berkeleyan news story, 2009)
6. A 2005-2011 survey in 10 California cities, including Riverside, La Cañada Flintridge and Palm Springs (Palm Desert), identified 229 bee species in 42 genera. (Source: Frankie et al., Journal of Pollination Ecology 25(3), 2019)
7. In that study, 16 of 19 non-native garden plants (84%) attracted non-native bee species, while native bees were common on both native and non-native plants. (Source: Frankie et al., Journal of Pollination Ecology 25(3), 2019)

Counts reflect survey effort as well as true diversity. The southern cities received less recorder time (220 person-days) than the northern ones (400). Riverside was added to monitoring later, so it has no count in the 2009 table.

Identification

How to tell native bees from honey bees and wasps

A quick look at size, hair, color and where the insect is going usually settles it.

1. Honey bees are medium-sized, about 1/2 inch, and nest in cavities such as attics, tree hollows and rock cavities. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
2. Honey bees have golden-brown hair, an orange abdomen with black stripes and pollen baskets on the hind legs. (Source: University of Arizona, Arizona Bee Identification Guide)
3. Up close, honey bees have hairs on their compound eyes and lack the tibial spurs on the hind legs that many native bees have. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
4. Large carpenter bees, at 20 to 28 mm with shiny black bodies and sparse abdominal hair, are much bigger than honey bees. (Source: University of Arizona, Arizona Bee Identification Guide)
5. Bumble bees are robust and hairy, 10 to 28 mm, with bands of black, yellow, orange or whitish hair. (Source: University of Arizona, Arizona Bee Identification Guide)
6. Leafcutter bees carry pollen on a brush of hairs under the abdomen rather than on the legs. (Source: University of Arizona, Arizona Bee Identification Guide)
7. Bees have branched hairs; wasp hairs are simple and straight, and wasps never have pollen-carrying hairs. (Source: USDA Forest Service, Bee Basics; University of Arizona Bee ID Guide)
8. Wasps are nearly hairless and often carnivorous, so a bee-like insect drawn to meat or table scraps is usually a wasp. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
9. Yellowjackets can be told from bees by their distinct yellow and black markings and lack of hair on the body and hind legs. (Source: UC Master Gardeners of Tulare-Kings Counties, 2023)

Identification guides cited here are from Utah State and the University of Arizona; the bee groups they describe also occur in California, but individual species differ.

Decline

Native bee declines and California's protected bumble bees

Some of the best-documented native bee declines involve bumble bees. As of CDFW's CESA web page (checked Nov. 2, 2026) and its considerations document dated Aug. 3, 2026, four California bumble bees are candidates for listing under the California Endangered Species Act (CESA). They are not yet listed as endangered or threatened; no final Fish and Game Commission listing decision had been announced.

1. A 2025 NatureServe study of nearly 1,600 North American pollinator species found 22.6% at elevated risk of extinction. (Source: NatureServe, news release on PNAS study, March 2025)
2. The same study found 34.7% of assessed native bee species at risk. (Source: NatureServe, news release on PNAS study, March 2025)
3. The leading threats named were climate change, agriculture, habitat loss and urban development. (Source: NatureServe, news release on PNAS study, March 2025)
4. A 2011 national study found four of eight bumble bee species studied had declined in relative abundance by up to 96%, with ranges contracting 23% to 87%. (Source: Cameron et al., PNAS, 2011)
5. The Xerces Society reported in 2018 that Crotch's bumble bee had declined 98% in relative abundance. (Source: Xerces Society, 2018)
6. The western bumble bee's relative abundance had declined by 84% since the late 1990s, per a Xerces analysis. (Source: Xerces Society, 2018)
7. The Suckley cuckoo bumble bee showed an 80% decline in relative abundance. (Source: Xerces Society, 2018)
8. Franklin's bumble bee has not been detected in California since 1998, or anywhere since 2006. (Source: California Department of Fish and Wildlife, 2026)
9. A UC Riverside-led census found 17 bumble bee species, only 68% of those historically known in California, and no western bumble bees at any of 17 sites. (Source: UC Riverside news release on Ecology and Evolution study, 2022)
10. The same census could not locate more than 10 bees at each of four Southern California sites at the time of the visits. (Source: UC Riverside news release, 2022)
11. Crotch's, western, Suckley cuckoo and Franklin's bumble bees became CESA candidates when the Fish and Game Commission's notice of findings was published on June 28, 2019. (Source: California Department of Fish and Wildlife, 2026)
12. Candidacy was stayed during litigation and reinstated on September 30, 2022, after the court of appeals upheld the Commission and the California Supreme Court declined to hear the case. (Source: California Department of Fish and Wildlife, 2026)
13. As of CDFW's Aug. 3, 2026 considerations document and its CESA web page (checked Nov. 2, 2026), the four bumble bees remained CESA candidates, the first insects to reach that status; no final listing decision had been announced. Candidates receive the same take protections as listed species. (Source: California Department of Fish and Wildlife, considerations document, Aug. 2026; CDFW CESA web page)
14. Crotch's bumble bee is nearly endemic to California, with its highest current and historical densities in the Los Angeles basin and greater San Diego area. (Source: California Department of Fish and Wildlife, 2026)
15. In warm, dry Southern California years, Crotch's queens may fly by late February; colonies are active March through August. (Source: California Department of Fish and Wildlife, 2026)
16. CDFW notes that several diseases can spread from honey bees and managed bumble bees to native bumble bees, and that acute insecticide exposure can kill them. (Source: California Department of Fish and Wildlife, 2026)

Decline figures vary by measure. Xerces reported an 80% drop in relative abundance for the Suckley cuckoo bumble bee, while a 2019 Center for Food Safety press release on the listing petition cited a 58% range decline. For Franklin's bumble bee, CDFW says it was last detected in California in 1998 and has not been detected anywhere since 2006; Xerces (2018) says it has not been seen in the wild since 2006. The court case is commonly known as Almond Alliance of California v. Fish and Game Commission. CESA status can change at future Fish and Game Commission meetings; check CDFW's CESA page for the current status.

At home

Native bees mistaken for a honey bee problem, and plants that help them

Two native bees are often mistaken for a honey bee problem in Southern California yards: carpenter bees in wood and ground-nesting bees in lawns. Neither builds a honey bee colony, and both are usually best left alone or gently discouraged with non-lethal steps.

1. Carpenter bees are considered pests only when they burrow into untreated wood used in construction; UC's Robbin Thorp advised weighing any damage against their benefits. (Source: UC ANR Bug Squad blog, 2017)
2. Xylocopa tabaniformis orpifex, the smallest of California's three large carpenter bees, can be a pest in untreated redwood water tanks and structural timbers. (Source: UC Davis Laidlaw Honey Bee Research Facility, native bees archive)
3. Mining bees nest underground in thin or patchy lawns. (Source: Utah State University Extension, Beginner's Guide to Common Native Bees)
4. NC State recommends non-lethal steps for ground bees, such as watering during the 3 to 4 weeks bees are active and thickening grass, since the bees prefer dry soil. (Source: NC State Extension, 2014, updated 2024)
5. Phacelia tanacetifolia attracted 57 bee species, Ceanothus 51 and California poppy 41 in the 10-city garden study. (Source: Frankie et al., Journal of Pollination Ecology 25(3), 2019)
6. Among non-native garden plants, lavender attracted 53 bee species, catmint (Nepeta) 52 and Aster x frikartii 43. (Source: Frankie et al., Journal of Pollination Ecology 25(3), 2019)
7. In the 2005-2007 survey, cosmos, lavender and catnip mint drew the most bee counts, partly because they bloom for long periods; Asteraceae and Lamiaceae were the most attractive families. (Source: Frankie et al., California Agriculture 63(3), 2009)
8. UC Master Gardeners advise leaving bare soil for ground-nesting native bees, and calling a beekeeper rather than approaching an active honey bee hive. (Source: UC Master Gardeners of Tulare-Kings Counties, 2023)

Phacelia's 57 species include 54 native and 3 non-native bees. For California poppy, the Frankie 2019 paper's text says 41 species and its table 42. The authors recommend mixing native and non-native plants to extend bloom and attract more species.

Questions

Frequently asked questions

Keep reading

Related on this site

• Carpenter bees in California
• Bee nest in the ground?
• Bee conservation in California
• Honey bee anatomy in 3D

How this page was made

Methodology & sources

Every fact on this page was traced to a primary source (a government data release, a university research or extension publication, a professional medical body or a peer-reviewed paper) and checked against the original document. Data years are given where they differ from publication years. Where reputable sources disagree, both figures are shown. Sources are named in plain text next to each fact.

• Frankie et al., California Agriculture 63(3), 2009
• Frankie et al., Journal of Pollination Ecology 25(3), 2019
• UC Berkeley, Berkeleyan, 2009
• UC ANR Bug Squad blog
• UC IPM Pest Notes: Bee and Wasp Stings, 2011
• UC Master Gardeners of Tulare-Kings Counties, 2023
• UC Davis Laidlaw Honey Bee Research Facility
• UC Riverside, 2022
• USDA Forest Service, Bee Basics
• USDA National Agroforestry Center / Xerces Society, AF Note 34, 2007
• USDA Agricultural Research Service, Agricultural Research magazine, 2010
• US Geological Survey
• Sam Droege, USGS Bee Inventory and Monitoring Lab
• Xerces Society
• California Department of Fish and Wildlife, 2026
• California Office of Historic Preservation
• NatureServe, PNAS, 2025
• Cameron et al., PNAS, 2011
• Sheffield, Heron and Musetti, Biodiversity Data Journal, 2020
• Ullmann, Meisner and Williams, Agriculture, Ecosystems and Environment, 2016
• Utah State University Extension
• University of Arizona
• NC State Extension
• Center for Food Safety, 2019