Solitary bees

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By contrast with social bees such as bumblebees and honey bees, where a number of worker bees share a single nest under a single queen, each solitary bee female lays eggs in its own individual nest or nests. However, large numbers of solitary bees may congregate in one area where there is plenty of nesting habitat, such as on a sunny bank – in other words, they may nest colonially.

There are some 250 different species of solitary bees in Britain, about 100 of which occur in Essex. All have a strictly annual lifecycle. Eggs are laid some time in the spring or summer and develop within the nest, emerging as adults the following year to mate and then repeat the cycle.

They nest in a variety of different ways: mining bees (such as the yellow-legged mining bee) dig burrows in the ground and carpenter bees in wood; some use plant stems or existing holes in wood; and some – cuckoo bees – avoid all the effort by laying in other bees' nests.

The red mason bee is one of the commonest and is important as a pollinator of fruit trees. Other solitary bees likely to be seen in gardens include leafcutter bees, that cut pieces out of leaves to line their nests, and wool carder bees, that collect plant hairs for the same purpose.

These bees are a similar size to honey and bumblebees, but some solitary bees are tiny. The harebell carpenter bee, for example, is small enough to get into woodworm holes and also nests in reed stems.


Photo © Tony Gunton