604 



INSECTA ORDER DIPTERA. 



Besides the true gnats or mosquitoes (Culicidce), some of the species be- 

 longing to several other families of this section of Diptera are extremely 

 troublesome, the females sucking the blood of men and 

 Gnats and animals. These are the sand-flies (Simuliidiv), and also the 



Sand-Flies. Chironomidce and Psychodidce. The larvae of all these 

 families, except the Psychodidce, live in water. The Culi- 

 cidce and Ghironomidce have more or less plumose antennae in the males, 

 which may often be seen on our windows. The transformations of the 

 common gnat are very curious, and have often been described. The female 

 gnat lays her eggs in a compact, boat-shaped mass, which floats on the surface 

 of the water. The larva swims head downwards, having a respiratory tube 

 at the hinder extremity of the body, through which it breathes. The 

 pupa is of a different form, and swims head upwards, the upper end of the 

 body, which is much thickened, being now provided with respiratory organs. 

 When it has arrived at maturity, the skin of the upper end of the pupa splits, 

 and the gnat gradually disengages itself, steps out on the surface of the water, 

 and flies away. The Simuliidce have short, broad wings, comparatively short 

 and stout antennae, a*id spotted legs, in which the first joint of the tarsi is as 

 long as the remaining joints. The larvae and pupae live in water, where they 

 form small cases, which they attach to grass-stems, weeds, stones, etc. Our 

 British species are harmless, or nearly so ; but in many countries, as in the 

 Banat of Hungary, for example, they form a terrible pest. The Psychodidw, 

 the last of this group of blood-sucking families which we shall notice, resemble 

 small moths, and sit on the underside of leaves, or run actively over them. The 

 principal blood-sucking species in this family is Phleboto mus papatom(Scopoli), 

 whichinhabitsthesouth-east of Europe. It is asmall, hairy, yellowish-brown fly. 



Next to the gnats and gnat-like flies, the most familiar insects belonging 

 to the Nemocera are the Tipulidce, which are generally called crane-flies, or 



daddy longlegs. These are flies 

 Family with long, narrow, transparent 



Tipulidce. or mottled wings, expanding 



Crane-Flies. from one to two inches ; a long 

 pointed snout, on each side of 

 which are moderately long antennae ; and a long 

 slender body, generally greyish-brown, but 

 sometimes banded with yellow, and terminating, 

 in the female, in a short horny point. They 

 have very long slender legs, which break ofl' at 

 the least touch. They are easily disturbed 

 when we are walking through the meadows, 

 when they flit a few feet, and settle again with 

 their wings extended. They frequently fly into 

 rooms at night, being easily attracted by a light. 

 Their grubs live in the ground, and feed on the 

 roots of grass, frequently causing whole fields 

 to wither and turn brown, as if parched up with 

 drought. The smaller insects of this rather ex- 

 tensive family resemble gnats in size and general f . 9 7._c RA NE-FLY 

 appearance, and some of them appear during the (Pachyrhina'crocata). Nat. size, 

 winter months. The species figured, Packyrhina 



crocaa(Linn.), is a rather handsome black and yellow insect, and is found in 

 woods. 



