There are 438 identified bee species in Pennsylvania, nearly 70% of which nest underground. About 33% of all these bees are active for only 4-6 weeks in early Spring. The most common spring bees in Pennsylvania include the solitary ground-nesting bees Colletes and Andrena species (commonly known as cellophane and mining bees, respectively). Although these bees are solitary (meaning that the female lives and rears brood on her own), they nest in large aggregations where hundreds to thousands of individual nests can be found in one small area. The female bee digs her nest underground, lays eggs on pollen provisions, and these eggs will develop and remain underground as a prepupa through the summer, fall, and winter until they emerge the following spring when flowers are in bloom.
The nests are obvious and easy to spot above ground because of the conical piles of dirt with a hole in the middle. If conditions are right, many times you can find these bees in your backyard. Although these bees are very common, the basic biology and diseases of most of these bee species are unknown and we want your help to find out more about them. The “Bee Germs” project is focusing on learning more about bees that live underground. We know very little about bees that make their homes underfoot; by learning more about their germs (or pathogens) we will be able to understand what diseases they are suffering from and, eventually, find ways to help them.