Plasterer bees (sometimes called yellow-faced bees when referring to Hylaeus species) are small to medium-sized solitary native bees that line their nest cells with a secreted, waterproof, plaster-like substance. Hylaeus species are particularly distinctive — they are small, mostly black bees with yellow or white facial markings, and unlike most bees they carry pollen internally (swallowed and regurgitated) rather than on external pollen-carrying structures. This makes them appear almost hairless and wasp-like. They nest in hollow stems, beetle borings, and other small pre-existing cavities. Colletes species (also called cellophane bees) line their ground nest cells with a polyester-like secretion. Both groups are important native pollinators in Arizona, visiting a wide variety of flowers. They are completely non-aggressive and pose no practical sting risk.
👁Warning Signs
Small, mostly black bees with yellow facial markings (Hylaeus) visiting flowers. Nesting in hollow stems or small wood cavities. Ground nest entrances in sandy soil (Colletes).
⚠Health & Property Risks
Essentially zero sting risk. No structural damage. Entirely beneficial.
Prevention Tips
No prevention needed.
🛡Professional Treatment
No treatment warranted.
Frequently Asked Questions — Plasterer Bee
The Plasterer Bee (Colletes / Hylaeus spp.) is black with yellow or white facial markings (hylaeus); black with pale hair bands (colletes) and typically measures ⅛–⅓ inch. Plasterer bees (sometimes called yellow-faced bees when referring to Hylaeus species) are small to medium-sized solitary native bees that line their nest cells with a secreted, waterproof, plaster-lik.
The Plasterer Bee is generally low-risk, but caution is still advised. Essentially zero sting risk. No structural damage. Entirely beneficial.
In Arizona, plasterer bees are most often encountered in the following situations: Small, mostly black bees with yellow facial markings (Hylaeus) visiting flowers. Nesting in hollow stems or small wood cavities. Ground nest entrances in sandy soil (Colletes).
The Plasterer Bee is most active during: Spring through fall; varies by species. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.
No prevention needed.
No treatment warranted.
If you are seeing plasterer bees repeatedly, finding evidence of an established population, or if DIY treatments have not resolved the issue within a week or two, it is time to call a professional. Pest Control Bros offers free inspections and same-week service across the Phoenix metro area — no contracts required.
Dealing with Plasterer Bee?
Pest Control Bros LLC serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa. No contracts. Free inspections. Same-week service.
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