• Family: Andrenidae
• Approximate # species in region: 107
• Common name: mining bees

One of the biggest groups of bees in our region, Andrena are most easily seen in spring, when dozens of species emerge to take advantage of spring ephemerals and woody plants in flower. A few species are active in midsummer, but most are uncommon (with the exception of the exotic and abundant A. wilkella). Late summer and fall see an Andrena renaissance as a new suite of species emerges to forage primarily on fall asters and goldenrods.

Female Andrena can be recognized (and distinguished from similar Colletes – see below) by their obvious facial foveae, a pair of parallel vertical depressions on the face that run along the inner margins of the compound eyes, and parallel (vs. convergent) inner eye margins. Andrena males lack foveae, but have the same parallel-sided eyes and rectangular face as females. They are less slender and bigger-headed than most Lasioglossum males and often have dense “mustaches”. Also remember that most Lasioglossum and Halictus males don’t fly until summer or fall, while males of most Andrena peak in abundance in spring!

Regional Species List: