Metallic Green Sweat Bee

Family Halictidae — the sweat bees — contains over 4,500 species worldwide and is one of the most ecologically diverse and scientifically important bee families. Agapostemon virescens (the bicolored striped sweat bee) is one of the most common and most beautiful North American halictids: females have brilliant iridescent metallic green head, thorax, and abdomen base, with a yellow-and-black-banded posterior abdomen. The family's common name comes from the well-documented behavior of landing on humans (and other large mammals) to drink perspiration — they are after the salt, sodium, and amino acids in sweat, a behavior shared with butterflies. The species rarely sting, and the sting is mild. Halictidae are scientifically remarkable because the family contains the full spectrum of social organization in a single phylogenetic group: solitary species, communal species (multiple females sharing a nest entrance but provisioning separately), semisocial species (cooperative provisioning by sister females), and fully eusocial species (queens with sterile worker daughters). This makes Halictidae a flagship group for studies of the evolution of eusociality in animals — Bert Hölldobler, E.O. Wilson, and others have used halictid biology extensively in The Insect Societies and Sociobiology. Sweat bees are major pollinators of wildflowers, garden plants, and many crops; they are also one of the most abundant native bee groups in North American gardens.