In Britain there are over one hundred different species of mining bees. Many of these are small and unlikely to be noticed by the general public, but two species, Andrena flavipes and Andrena fulva are often the subject of enquiries. This is because they tend to have large colonies in suitable areas of short turf, in fact A. fulva is sometimes called the Tawny Lawn Bee. The nest burrows are marked by small piles of excavated earth. Each female lives for about four weeks and there may be one or two generations each year depending on the species involved.
Neither of these species, or any other mining bee, pose any threat to humans: unlike honeybees and the social wasps which have ‘spare’ workers and a valuable colonial nest to protect. The ultimate sacrifice a worker honeybee can make is to sting a potential nest-robber, leaving the sting in the victim and the insect dead. Each female Andrena bee, however, has its own nest burrow and no spare capacity to attack a possible threat. The bees will only try and sting if personally threatened by being held in the fingers, and even then the sting is rarely able to penetrate thick human skin. The female bees collect pollen and nectar which they store in small chambers, laying an egg in each completed cell and never looking at it again. As the females collect their pollen they perform essential pollination services in gardens and the general countryside; apples and soft fruit are often major beneficiaries of their visits. The egg hatches into a larva which eats the stored pollen and nectar, pupates and eventually emerges from the nest burrow as a new adult bee.
The first thing which draws attention to the nest area is often the cloud of males which fly rapidly over the ground where the females are emerging on a warm spring day. They pounce on anything which looks suspiciously like a newly emerging female bee and attempt to mate. They get so enthusiastic that quite large balls of males can form, all trying to be the lucky one. They are also pretty poorly sighted, jumping on anything which moves in the area, including other males. Being males they have no sting, so although they may look daunting, they are completely harmless.
There are also cuckoo bees (Nomada fucata specialises on A. flavipes) which fly over the nest area searching for nests to attack. They do this by crawling down the nest-burrow and searching for completed cells in which to lay their eggs – the rest of the story is the familiar cuckoo one where the Nomada larva eats all the food meant for the Andrena larva. These bees are often yellow and dark-brown striped (they are advertising their dangerous nature to any bird which tries to pick them up to eat). Again, they are not in the least bit interested in stinging us.