Halictidae > Agapostemon > Agapostemon sericeus
Silky striped-sweat bee (Agapostemon sericeus) is a backyard Agapostemon, often found alongside A. virescens. Females are exquisite: metallic green with silver abdominal bands that glisten in the sun. A. sericeus are field-identifiable, with a bit of practice and a camera or hand lens: their unevenly rough-textured thorax is unique among green Agapostemon in the region. We expect to find this species in most places we look for bees, including gardens, wet meadows, and agricultural field margins.
Phenology
Active from late spring through fall. The number of generations produced per year is dependent on locality, e.g. two generations per year in Kansas, one generation per year in New York.
Range
Widespread throughout northeast.
Morphology
Size ≈ honey bee
Males: green thorax with yellow-and-black abdomen, similar to other male Agapostemon but with light-colored sternites.
Females: all green with silvery abdominal bands, rough “sandpaper” thorax that is roughest near head, long golden-white scopal hairs, not particularly hairy on sides of thorax
Similar species
- A. splendens females have brown wings and evenly fine-textured thorax.
- A. texanus females have a smooth and shining thorax. A. texanus gives a much more metallic blue-green impression at first.
Males are hard to distinguish from males of Agapostemon and are often not field-identifiable:
- A. splendens males have brown wings and swollen hind femur.
- A. virescens males have relatively darker sternites.
- A. texanus males likely cannot be told reliably from those of A. sericeus in the field
Nesting
A. sericeus nests in soil in a variety of habitats, including gardens, lawns, agricultural fields, roadsides, and wet meadows. Nests are solitary, but can occur within aggregations of other ground-nesting summer bees, e.g. other Agapostemon, Andrena, Halictus. Nest entrances are likely not sealed during foraging bouts.
Foraging
Generalist. Forages from wide range of plant families, especially Asteraceae and Rosaceae. In the fall, principally associates with asters: goldenrods (Solidago spp.), snakeroot (Ageratina altissima), wood asters (Symphyotrichum spp., Eurybia spp.), but also visits late-blooming mints like Russian sage (Salvia yangii) and garden mints (Mentha spp.) for nectar.
Natural Enemies/Associates
Nomada articulata is a brood parasite (with parasitism rates as high as 74% of brood cells). Sphecodes davisii is also a brood parasite (recorded under the synonymous name Sphecodes persimilis).
References
Eickwort, G.C. 1981. Aspects of the nesting biology of five nearctic species of Agapostemon (Hymenoptera: Halictidae). J. Kans. Entomol. Soc. 54: 337-351.
Portman, Z. M., Arduser, M., Lane, I.G., Cariveau, D.P. 2022. A review of the Augochloropsis (Hymenoptera, Halictidae) and keys to the shiny green Halictinae of the midwestern United States. ZooKeys. 1130: 103-152.
Text last updated:
February 22, 2023