As in the case of Andrenæ, several tunnels are often made with one common entrance. The insect is very small, scarcely exceeding the sixth of an inch in length. The head and thorax are a dark green, the abdomen is white, and the legs are covered with silvery hairs. It is a plentiful insect, and is found haunting the holes of old walls.
Passing to another family of British mining-bees, we come to one species that is remarkable not only for its form, but for its economy. This is the _Eucera longicornis_, the only known species that inhabits England. In form it is chiefly remarkable from the fact that the antennæ of the male are as long as the entire body. The pupa of this insect is enclosed in a thin membrane, and when the male insect is about to emerge from its pupal shell, it has recourse to a rather curious expedient. At the base of the first joint of the front feet there is a bold notch. When the insect wishes to remove the thin membranous pellicle which envelopes the antennæ, it lays these organs in the notch, draws them through, and thus easily strips off the pellicle. The antennæ are most beautifully formed, the surface of each joint being marked with an elaborate pattern like net-work, so that they form beautiful objects for the microscope.
The soil preferred by the _Eucera_ is of a clayey nature. When it has completed the burrow, it presses the soil at the extremity with all its might, and smooths it so carefully that the burrow becomes capable of holding honey without needing any lining. The insect is generally found about the end of May or beginning of June, and in some places is found in great numbers. The ground colour of the insect is black, but the body is covered with a coating of short dun hairs. The length rather exceeds half an inch.]
CARPENTER-BEES; CARPENTER-WASPS; UPHOLSTERER-BEES.
Among the solitary bees are several British species, which come under that class called carpenter-bees by M. Réaumur, from the circumstance of their working in wood, as the mason-bees work in stone. We have frequently witnessed the operations of these ingenious little workers, who are particularly partial to posts, palings, and the wood-work of houses which has become soft by beginning to decay. Wood actually decayed, or affected by dry-rot, they seem to reject as unfit for their purposes; but they make no objections to any hole previously drilled, provided it be not too large; and, like the mason-bees, they not unfrequently take possession of an old nest, a few repairs being all that in this case is necessary.