The male Long-horned Bee Eucera longicornis is a fabulous insect, unmistakeable with his outsized blue-black antennae. Sadly this bee has declined significantly in the last 30 years and is now found at scattered sites in southern England. In fact there used to be a second species Eucera nigrescens but this has not been seen since the 1970s. The south Devon coast around Prawle is now the stronghold for this bee in Britain and the only site where the populations are strong enough to support its cuckoo bee Nomada sexfasciata. The cuckoo bee doesn’t makes its own nest but lays an egg in the long-horned bee nest and its larva kills the host larva and eats all the pollen collected for it.
I have been watching these bees for the last few years around Prawle and was delighted to find a big colony this year nesting along a stretch of low clay cliffs which I hadn’t searched before. Here there were at least 40 males buzzing around the nest sites intercepting females and attempting to mate with them. Male solitary bees are not subtle in their courtship. They spend their brief lives patrolling nesting areas and patches of flowers nearby, jumping on any females, and sometimes other males by mistake, and attempting to mate with them.
All male solitary bees have antennae longer than the female but this has been taken to an extreme in this species. The antennae are also twisted like long pieces of curled liquorice and must be quite a weight for the males to carry about.
These bees are specialists of clovers and vetches. The females only collect pollen from these flowers and are especially fond of everlasting peas and meadow vetchling. Depending on the weather conditions they fly from late May until July. The larger females excavate burrows in vertical clay cliff faces in which to nest. They are solitary bees, so each burrow is the nest of just one female but they often nest in dense aggregations and the cliff face may become__ honeycombed by their burrows. The males die off in late June leaving the females in peace to provision their burrows for a few more weeks.