NATURAL HISTORY. 



FAMILY VI. PSYCHODID.E. 



This family includes only a few curious little insects very nearly allied to the preceding, and, 

 indeed, they are often placed with the Cecidomyidse. They are little moth-like creatures, with 

 broad, deflexed, oval -wings, and both wings and body thickly covered with hairs. In the structure 

 of the antenme they agree with the Cecidomyidse, but the body and legs are shorter and stouter 

 than in the insects of that family, and the wings are not only very broad, but have the veins, 

 although not much branched, tolerably numerous. 



The best-known species is Psychoda phalcenoides, a common British insect, about a tenth of 

 an inch long, with brownish-grey wings, which it carries divergently, as it runs about upon the surface 

 of walls and window panes. It might easily be v mistaken for a minute Moth. The larva lives in 

 manure-heaps and among decaying vegetable matter, and is of an elongated form, with a slender, 

 straight, cylindrical, horny tail ; and the pupa has two short appendages just behind the head, in the 

 same position as the breathing tubes of the pupa of the Gnat. Another rather larger British species 

 (P. sexpunctata) has the wings rather elegantly marked with dark brown clouds or bands, and with 



black marginal spots. 



FAMILY VII. BIBIONID^E. 



This last family of the Nemocerous Diptera includes a number of fly-like species; in fact, they 

 are the division " Musciformia " of some writers. They have the body and legs considerably shorter 

 and stouter than the species of the other families ; the antennae short, seldom longer than the head, 

 but composed of from eight to twelve joints ; the wings large, with abundance of veins, but with 

 few closed cells. The palpi are generally four-jointed ; the eyes are rounded, and in the males 



generally occupy nearly the whole surface of the head ; and in most 

 of them there are three ocelli. 



The typical Bibionidae, including the genus Bibio and its im- 

 mediate allies, are sometimes called "Garden Flies;" they are usually 

 black and hairy, but often with some parts of a lighter colour, 

 especially on the limbs ; and they are commonly met with on flowers 

 in fields and gardens, particularly in the spring and early summer. 

 The females frequently differ in colour from the males. Thus in 

 Bibio hortulanus, a common British species, the male is black, 

 clothed with whitish hairs ; while the female is reddish-yellow, with 

 the head, scutellum, and legs alone black, and the wings in the two 

 sexes differ in coloration. In another abundant species (Bibio marci), 

 so called from its appearing about St. Mark's Day, the male has 

 white wings and the female brown ones. Both sexes of this species are black, and clothed with black 

 hairs. These insects fly heavily, and are sluggish in their general movements. 



The females lay their eggs in the ground or in manure-heaps, and the larvae feed either upon 

 decomposing animal and vegetable matter, or, in some cases, upon the roots of plants, which they 

 are said occasionally to injure considerably. These larvae are cylindrical worms with ten 

 stigmata along each side ; they are furnished with numerous short hairs, which appear to assist 

 them in progression. The minute larvae of the species of Scatopse live in excrements. When 

 full grown, the larvae of the ordinary Bibionidae make smooth oval cells in the ground, not far 

 from the surface, and there in the spring they change to the pupa state, in which the insect remains 

 for about a fortnight and then comes forth, the females preceding the males by about a week. 

 The pupa is naked. 



In the genus Simuliiim, which may be referred to this family, although separated from it 

 by some entomologists, all the parts of the mouth are fully developed, as in the Gnats, although 

 the proboscis is much shorter, and the insects are able to inflict very severe wounds with these 

 natm-al weapons. Among the Mosquitoes of South America at least one species of this genus is 

 included ; under the name of " Sand Flies " they are well-known plagues in many parts of North 

 America. In Lapland, and other northern regions, they co-operate with the Gnats in tormenting the 

 inhabitants, and even in England they often bite people very severely. But the most formidable 



BIBIO MARCI (MALE). 



