eastern North America
Fine-art photographic collection
Ptilothrix bombiformis
A specialist bee that walks on water, drinks it and uses the load to soften concrete-hard soil for a nest.
About this species
Rose-mallow Bee
Ptilothrix bombiformis(Cresson, 1878)
Information reviewed15 July 2026
Ptilothrix bombiformis is a solitary bee closely associated with rose mallows and other Hibiscus. Females nest in hard ground, often near water, and use collected water to soften the soil while excavating their burrows.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Apidae · Ptilothrix
Accepted taxon. · checked 2026-07-15
eastern North AmericaBroad range and selected reference localities — not a complete occurrence map.
Wetland margins, riverbanks, gardens and sandy or compact ground near stands of Hibiscus.
Summer flight coincides with flowering rose mallows.
Pollen and nectar, with a strong specialisation on Hibiscus and related mallows.
Solitary, often nesting in dense aggregations.
What makes this species remarkable?
A female can land on the water surface, skate across it and suck up a load that she carries back to soften sun-baked nesting soil.
The entrance may be raised into a mud chimney, while the underground brood cells are lined and sealed to protect developing larvae from moisture.
Its life is timed to rose-mallow flowers: females rapidly strip Hibiscus anthers while males patrol blooms and grapple for access to mates.