THE HUMBLE BEE FLIES. 89 



the tarsi yellow, measures about half an inch long, and has a proboscis three-quarters of an inch 

 in length. These long-trunked species feed upon the juices of flowers ; the labrum is very 

 short, and the three bristles enclosed in the proboscis are thin. Most of the European species 

 are destitute of a proboscis, and apparently take no food after arriving at the perfect state. The3 r 

 are not abundant, and are feeble and slow in their movements, generally passing their time upon 

 leaves and flowers, or sitting upon the trunks and branches of trees, about which they often 

 fly in the bright sunshine. The females deposit their eggs, which are very numerous and black, 

 upon the dried twigs of trees. Scarcely anything is known of their preparatory states, but it 

 is supposed that the larvae are parasitic in their habits. 



FAMILY XIV. BOMBYLIID^]. 



The Humble Bee Flies, which are the typical forms of this family, agree, to some extent, with 

 the preceding insects in general form, although they have not the thorax and abdomen so much 

 inflated ; but the group includes a number of species which show no such structure of the body. 

 They have rather a small head, with large eyes which usually meet in the male, and three ocelli ; 

 the antennae are of moderate length, of three joints, and well extended in front of the head ; the 

 proboscis is long and projected in front of the head, and the bristles contained in it are very delicate ; 

 the abdomen consists of six or seven segments ; the legs are long and thin, and the tarsi have three 

 pulvilli, of which the middle one is often hair-like ; the wings diverge on each side of the body, 

 and there is no scale covering the halteres. The transformations of these insects are somewhat 

 imperfectly known, but the larvae of many of them are undoubtedly parasitic upon other insects, some 

 attacking the caterpillars of Lepidoptera, while others live in the nests of different species of solitary 

 Bees. 



The great majority of the species of the family are exotic, and they occur in all parts of the 

 world. The most extraordinary development of the proboscis occurs in a species from the Cape of 

 Good Hope, Nemestrina longirostris, which measures about two-thirds of an inch in length, and 

 has a proboscis nearly three inches long, which it employs in sucking the nectar from the long- 

 tubed flowers of the gladioli, &c. The sweet juices of flowers, in 

 fact, constitute the general food of the insects of this family, and 

 in search of it they sweep from flower to flower with a rapidity 

 that shows great strength of wing ; and while engaged in probing 

 the recesses of the flowers with their long trunks, they usually 

 hover motionless in the air, like minute Humming-birds. They 

 generally show no brilliancy of colour, shades of brown and 

 black being the prevailing tints. The typical Bombylii, which 

 are stout-bodied insects densely clothed with hairs, somewhat like 

 little Humble Bees, are represented in Britain by about four species, 

 out of over a hundred which exist in other parts of the world. BOMBYLIUS MAJOR. 



Two of them (Rombylius major and B. medius), which measure a 



little under half an inch in length, are common in gardens and woods, and on sandy heaths, during the 

 spring and summer. They are both black, and clothed with tawny or yellowish hairs, but the 

 former has transparent wings, with a dark brown stripe starting from the base and running along 

 the anterior margin nearly to the tip of the wing, while the second has greyish wings, with a 

 yellowish-brown band manning from the base along the fore border, and beneath it a series of brown 

 spots. In the genus Anthrax, species of which are met with in dry places flying over the surface 

 of the ground in the hot sunshine, and resting from time to time, with their wings widely expanded, 

 "upon a stone or other projection, the base and fore margin of the wings are usually black, the dai-k 

 and light parts of the wings generally occupying nearly equal spaces. 



FAMILY XV. LEPTID^E. 



The Leptidae form a very small family allied to the preceding, but having the antennae very 



short, composed of three joints, of which the last is bent down, and bears a bristle either at its 



apex or near its base. The proboscis also differs, being skort and thick, and terminating in a 



pair of fleshy lobes. There are three bristles in the proboscis, and the palpi are long and 



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