Hoary squash bee (Peponapis pruinosa)

Apidae > Peponapis > Peponapis pruinosa

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.

Phenology

Mid-June through July. One generation per year.

Range

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.

Appearance

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.

Similar species

  • 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.

Nesting

Ground-nesting, sometimes in aggregations near or beneath squash Cucurbita pepo plants. Known to nest directly in or in the margins of agricultural fields.

Foraging

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).

Natural Enemies

Triepeolus remigatus is a cleptoparasite.

References

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