Mining bees, mason bees, carpenter bees, sweat bees, leafcutting bees, and hive bees

Bees that may look and/or sound like bumblebees, but are not bumblebees

Recently I've been getting a lot of e-mails from people wanting to know about bees that are obviously not bumblebees, but may resemble them. Usually the writers are concerned that these bees are causing some damage to their property, or are a danger to children and pets, and naturally they want to know what to do.

Almost all of them are classed as solitary bees, i.e. the female doesn't stick around after laying the first batch of eggs and providing a food supply (pollen and nectar), so the nest size is tiny. However some do nest communally either close together or using a common entrance hole, making it look a little like they are social bees.

These bees are generally less hairy than bumblebees and usually, but not always, smaller. The colour and pattern of their hairs varies, but is rarely the yellow and black seen in the commoner bumblebee. They fall into four main groups, miners, carpenters, masons and leafcutters.

Mining bees.

These bees generally nest in the ground, often in paths or lawns, and some of the lawn nesting species nest communally. The entrance to their burrows are often marked by a small mound of excavated soil (see right. These bees are good pollinators of economically important plants such as fruit trees and alfalfa. In reasonable numbers these bees won't harm your lawn.

There are about 100 species of mining bee in Britain, most resemble honey bees, but are smaller in size. Their burrows can be 60 cm deep. The clump of pollen takes the mother bee 6 - 7 journeys to gather. And each load is around half her body weight. Once the pollen clump is the right size she lays an egg on it.

Carpenter bees.

These bees have powerful mandibles (jaws) that can dig tunnels in wood. Xylocopa violacea (below), a huge (20-23 mm long), black bee found in central and southern Europe nests in dead wood and digs a tunnel up to 30 cm long containing 10-15 cells.

The photograph below right is of a Xylocopa violacea hole. This bee holds the record for laying the largest egg of any insect. Carpenters are found in many parts of the world, and ther>e is one very similar to this commonly seen in the USA. Naturally a large number of carpenter nests in the structural support of a building will cause some damage, but this is unusual.

Alarming carpenter bee behaviour

One behaviour can be alarming though. The males compete with other males to mate with females. This involves them chasing males away and

chasing females to mate. During these chases they zoom about crashing into windows, people and anything else in their path. Humans in the way of all this may think they are under attack, they are not, they are just in the way. Males may also hang around waiting for adult females to emerge, and again they behave in what might seem to us as an aggressive way, by chasing other males away and investigating anything that gets near the exit hole. This

something may be your head, you will be buzzed around and checked out to see if you are a rival that needs chasing away or a female that needs mating. However there is no danger as males cannot sting, so like much male mating behaviour it's all bluster and show.

carpenter bee tunnel entrance in old wood in central Paris

Mason bees.

These bees will nest in almost any cavity which they can modify in shape with earth or other materials to suit their requirements. Some species specialise in nesting inside snail shells, and there is a tiny species that nests in the holes left by wood worm beetles. The European species Osmia rufa, Red osmia is often found nesting in old nail holes and in the mortar of old walls. Osmia sp. collect pollen in the dorsal hairs of theeir abdomen - similar to some leafcutters.

Others, like Anthophora retusa, on the left construct cells using clay, sand, earth and chalk, and earth mixed with wood - whatever is at hand. Anthophora retusa looks like a small, dark bumblebee, but she has orange-coloured hairs on her hind legs. In the UK this bee appears in the early spring and flies until July, it is an important fruit pollinator.

In towns their nests can often be found between two bricks in walls. The nest on the right has only two cells, if space permitted there would be more.