Description

Fairy bees are small to minute, ground nesting bees native to the United States and Mexico. Bolton’s fairy bee adults possess dark metallic green heads and thoraxes, and darker, almost black abdomens. The body and appendages are covered with fine yellow hair (setae). The wings are iridescent, translucent and papery in texture. The extremities of the antennae and legs are reddish brown. The compound eyes are large and finely faceted. Three simple eyes (ocelli) form a triangle on top of the head. Both males and females are about 5 mm in length.

The bee fauna of Louisiana includes 266 known or suspected (based on surveys performed in adjacent states) species, including several species that have never been formally described. Seven species of fairy bees (Perdita spp.) are recorded for Louisiana. Due to their small sizes, similar appearances and large species diversity (over 500 described species), fairy bee identification to species is difficult and requires examination of subtle anatomical details under high magnification.

Life Cycle

Detailed research on only a few fairy bee species has been performed, but the life cycles are similar and typical of most ground nesting solitary bees. Adults or mature pupae overwinter in burrows and emerge and mate during spring. Females excavate long tunnels that vary from 12 cm to over 40 cm, depending on species. Brood chambers are excavated at intervals along the main tunnel or side branches. These chambers are provisioned with pollen, which serves as the larval food. Eggs are deposited on this bed of pollen, and larvae begin feeding immediately after hatching. The larvae remain in their larval cell feeding until they transform into pupae. When metamorphosis is complete, the adults dig their way out of the sealed burrow and begin feeding on nectar and seeking mates. Mated females excavate tunnels to begin the next generation. Little is known about the detailed life history of this species and ground nesting bees generally, other than a few well-studied species.

Ground nesting bees are solitary and do not share burrows with each other, but they are often gregarious, with large numbers of bees digging burrows in a small area. These nesting aggregations may persist for several years if conditions remain favorable.

Ecological Significance

Most fairy bee species are found in arid and semiarid habitats in southwestern U.S. and Mexico, Bolton’s fairy bee is found in eastern and central United States and Mexico. Only a few confirmed records are from Louisiana, but the species is likely common and widespread in the state. Adults are most active during July and August. Host plants include asters (Chrysopsis spp.), fleabanes (Erigeron spp.), camphorweed (Heterotheca subaxillaris) and narrowleaf silkgrass (Pityopsis graminifolia).

Bolton’s fairy bee is one among many important native pollinators that are critical to ecosystem function. Most native bee pollinators are solitary, nonsocial species that do not form colonies like non-native honeybees and native and non-native bumblebee species. Native bees pollinate more than just flowers. They pollinate many field and home garden crops, in many cases outperforming honeybees as pollinators. Research by U.S. Department of Agriculture and university scientists has demonstrated that soybean plots containing a mix of native bee species and honeybees are more productive than plots with only honeybees or only native bees. Support for native bee populations can be enhanced by planting a wide variety of native flowers, providing open ground for nesting aggregations and building nesting areas for native bees (e.g., bee hotels). Artificial nests should be cleaned annually to prevent the buildup of parasites and diseases. Providing native bee habitats can be a great way to help the environment and learn about species occurring in your area, including, potentially, documenting new species for the Louisiana fauna.

References

• Bartholomew, C.S., D. Prowell, and T. Griswold. 2006. An annotated checklist of bees (Hyme-noptera: Apoidea) in longleaf pine savannas of southern Louisiana and Mississippi. Journal of the Kansas Entomological Society (79):185–198.
• Danforth, B.N. 1988. Nesting behavior of four species of Perdita (Hymenoptera: Andrenidae). Journal of the Kansas Entomological Society 62: 59-79.
• Discover Life. n.d. Perdita boltoniae. https://www.discoverlife.org/20/q?search=Perdita+b... (accessed 31 March 2024).
• Hall, H.G., and R. Tyler. 2022. Survey of the bee (Hymenoptera: Apoidea) fauna of northwestern Louisiana. Proceedings of the Entomological Society of Washington 123: 766-783.
• Michener, C.D. 1947. Bees of a limited area in Southern Mississippi (Hymenoptera: Apoidea). The American Midland Naturalist 38: 443–455.
• Owens, B.E., L. Allain, E.C. VanGorder, J.B. Bossart, and C.E. Carlton. 2018. The bees (Hymenoptera: Apoidea) of Louisiana: an updated, annotated checklist. Proceedings of the Entomological Society of Washington 120: 272-309.
• USGS. 2015. Native Bees. (Accessed 31 March 2024).

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9/16/25
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Adult male Perdita boltoniae (mmcarthy98, iNaturalist, Creative Commons 4.0).

Perdita boltoniae adult, frontal view (cpgibson, iNaturalist, Creative Commons).

Perdita boltoniae adult from Caddo Parish, Louisiana (royaltyler, iNaturalist, Creative Commons 4.0).