Pruinose squash bee (Peponapis pruinosa) is one of the most common vegetable garden pollinators in the northeast. With a bright orange thorax and protruding clypeus, males and females are distinctive among regional eucerines. For P. pruinosa, the early bee gets the pollen: females are active very early in the morning to coincide with the opening of squash blossoms. Males may be found resting in closed flowers in the afternoon.
Mid-June through July. One generation per year.
Widespread, especially near cultivated squash. Recent molecular analyses indicate a large population-level expansion over the past few thousand years of P. pruinosa following cultivation and trading of squash by indigenous people in the Americas.
Size ≈ honey bee
Females with protruding clypeus, bright orange thorax, smudgy banding on abdomen, and long eyelash hairs on scopae.
Males like females but with longer antennae and no scopae.
- Melissodes trinodis/agilis has a similarly bright orange thorax, but lacks protruding clypeus, has more crisp abdominal bands, and is never found on squash (nearly always found on sunflowers and other summer-blooming Asteraceae).
- Often the only non-Bombus, non-Apis bees on squash. Melissodes bimaculatus is also found on squash but is entirely black.
Ground-nesting, sometimes in aggregations near or beneath squash Cucurbita pepo plants. Known to nest directly in or in the margins of agricultural fields.
Pollen specialist on squash (Cucurbita), with a preference for the larger-flowered squash in gardens (C. pepo and C. moschata). Known also to nectar on non-squash flowers including morning glories (Ipomoea) and pickerelweed (Pontederia cordata).
Triepeolus remigatus is a cleptoparasite.
López-Uribe, M.M., Cane, J. H., Minckley, R.L., and Danforth, B.N. 2016. Crop domestication facilitated rapid geographical expansion of a specialist pollinator, the squash bee Peponapis pruinosa. Proc. R. Soc. B. 283: 20160443.
Page last updated:
January 17, 2023