Mining Bee (Genus: Andrena)

5 May

Here we are in the realms of “really hard identification” so for now I am only going to allocate it to a genus and not go into the muddy water further down the taxonomic tree. Nevertheless, here we have one of several very small bees that were buzzing around the Sanguinaria and a few other early spring ephemeral flowers in the garden. In fact, I was lucky to get this picture they move so fast.

Andrena is the largest genus in the family Andrenidae, and is nearly worldwide in distribution, with over 1,300 species which are often brown to black with whitish abdominal hair bands. Andrena bees are distinguished from most other small bees by the possession of broad velvety areas in between the compound eyes and the antennal bases, called “facial foveae”. They also tend to have very long scopal hairs on the hind leg. This bee was slightly over a half centimetre long.

Overwintered adults emerge in the spring, males slightly before females, mating occurs shortly thereafter. After mating, females begin constructing their nests – a vertical tunnel lined with a shiny water-proof secretion and side cells. Andrena are more active than Apis (honey bees) at lower temperatures and can be, on a per bee basis, superior pollinators in cold weather.