482 INSECTS INJUKIOUS TO VEGETATION. 



The head is small, and almost hidden under the thick and 

 hunched thorax ; the antennae are many-jointed, slender, and 

 tapering; the hind body is long, narrow, and somewhat flat- 

 tened ; the legs are very slender next to the body, and increase 

 in thickness towards the end, and the first joint of the feet is 

 swollen, oblong oval, and very downy. The length of the 

 body is about half an inch, and the wings expand nearly three 

 quarters of an inch. It appears in July, and takes wing by 

 day. As it flies slowly along, it seems almost to tread the 

 air, balancing itself horizontally with its long legs, which are 

 stretched out, like rays, from the sides of its body. 



There are exceptions to almost all general rules. Thus we 

 find, among Dipterous insects, some kinds that never have 

 wings. One of these is the thick-legged snow-gnat, or Chionea 

 valga. This singular insect looks more like a spider than a 

 gnat. Its body is rather less than one fourth of an inch long, 

 and is of a brownish yeflow or nankin color. The legs are 

 rather paler, and are covered with short hairs. The head is 

 small and hairy. The first two joints of the antennae are 

 thick, the others slender and tapering, and beset with hairs. 

 Although the wings are wanting, there is a pale yellow poiser 

 on each side of the hinder part of the thorax. The hindmost 

 thighs are very thick, and somewhat bowed, in the males, 

 which suggested the name of valga, or bow-legged, given to 

 the insect in my " Catalogue." The body of the female ends 

 with a sword-shaped borer, resembling that of a grasshopper. 

 These wingless gnats live on the ground, and the females bore 

 into it to lay their eggs. They are not common here. Mr. 

 Gosse found considerable numbers of them in Canada, crawl- 

 ing on the snow, in pine woods, during the month of March.* 



Travellers and new settlers, in some parts of New England 

 and Canada, are very much molested by a small gnat, called 

 the black fly (Simulium rnolestum), swarms of which fill the air 

 during the month of June. Every bite that they make draws 

 blood, and is followed by an inflammation and swelling which 

 last several days. These little tormentors are of a black color ; 



* " Canadian Naturaliat," p. 61. 



