Nature on our doorsteps: Mining Bees

Rosaleen Dwyer is the County Heritage Officer at South Dublin County Council – every week she gives us an insight into the natural heritage around us and the beautiful biodiversity of the plants and creatures

Honeybees and bumblebees are known as social insects.

They live as colonies in hives or nests. They are governed by a queen, and they stay with their young to feed and protect them.

Solitary bee species, however, do exactly as their name describes. These live on their own. They do not live together in nests or hives, and they are not ruled by a queen.

Different solitary bee species make different types of nests. Some burrow underground while others make use of existing holes or cavities in walls or in wood.

Mining bees burrow little holes into the soil to form a nest, and two species of mining bees are noticeable in our parks and gardens at the moment.  These are the very aptly named Ashy Mining Bee and the Orange-tailed Mining Bee.

As female mining bees dig their burrow, they dump the soil around the entrance hole where it piles up into the shape of a little volcano. She will then lay her eggs in the underground chamber and leave them to develop by themselves.

The orange-tailed Mining Bee has a bright ginger back and beautiful blond hairs on its legs

Before sealing the entrance of the nest, however, the female leaves a large supply of pollen to feed the larvae as they grow and develop. This needs to be a substantial supply, so she is busy for days visiting many, many, flowers before she finally seals the nest.

Female mining bees lay fertilised eggs at the back of the nesting chamber which develop into female larvae.

Those eggs laid to the front of the chamber are unfertilised and these grow into males. These males develop and emerge first from the chamber, heading off in search of a mate.

Of Ireland’s 100 wild bee species, there are 77 different solitary bee species, all of which collect a lot of pollen to leave in their nests. This collecting effort makes solitary bees very important as pollinating insects.