MIDGES, SAND=FLIES, ETC. 



Certain genera are grouped by some good authorities in a 

 separate family, CORETHRHXE. The wings and body are 

 covered with hairs instead of scales. The adults look 

 like mosquitoes, but probably do not feed, certainly do not 

 bite; the larvae are predatory, often cannibalistic, whereas 

 mosquito larvae are vegetarians; and the larvae, for the most 

 part, do not breathe atmospheric air but get their oxygen 

 by absorption from the water. These young Corethridae 

 are called Phantom Larvae on account of their almost 

 complete transparency. By looking carefully one may 

 see them in still, shaded pools, keeping a horizontal 

 position a little below the surface of the water. The eyes 

 are dark, and there are two pairs of dark spots, one pair on 

 the thorax and one near the end of the abdomen. These 

 are "air-sacs." I do not know how the air gets in there 

 or if it is real air. The pigment in the lining of these sacs 

 may have something to do with it. The pupa floats in 

 an upright position and doubtless gets atmospheric air 

 through the respiratory trumpets on the top of its head. 



CHIRONOMID^E 



This is a large family of delicate, often minute, flies, 

 commonly known as Midges. The costal vein does not 

 go further than the tip of the wing. ' The larvae are soft- 

 skinned, worm-like, often blood-red in color and usually 

 aquatic, as are also the active pupae, though some live in 

 decomposing vegetable matter, or in the earth. These 

 midges are often seen, especially in the early spring or in 

 the autumn, in immense swarms, dancing in the air, and 

 have doubtless in many cases given rise to exaggerated 

 stories of mosquitoes. . . . While at rest they usually 

 raise their fore legs in the air and keep them constantly 

 vibrating" (Williston). Most of the adults are harmless, 

 but Sand-flies, Punkies, and No-see-ums, belonging to the 

 genus Culicoides, make life miserable. They are the 

 smallest blood-suckers, some of them being only .04 in. 

 long. Some larvae live under bark and fallen leaves, and 

 in sap flowing from wounded trees. Chironomus has 

 many inoffensive species; the larvae are common in tubes 

 in soft mud. 



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