DIPTERA. 405 



females bore into it to lay their eggs. They are not common 

 here. Mr. Gosse found considerable numbers of them in Canada, 

 crawling 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 (Simuliujn molestum), swarms of^ which fill the air during the 

 month of June. Every bite that they make draws blood, and is 

 followed by an inflammaiion and swelling which last several days. 

 These little tormentors are of a black color; their wings are 

 transparent ; and their legs are short, and have a broad whitish 

 ring around them. The length of their body rarely exceeds one 

 tenth of an inch. They begin to appear in May, and continue 

 about six weeks, after which they are no more seen. They are 

 followed, however, by swarms of midges, or sand-flies (SimuHum 

 nocivum), called no-see-'em, by the Indians of Maine, on ac- 

 count of their minuteness. So small are they, that they would 

 hardly be perceived, were it not for their wings, which are of a 

 whitish color, mottled with black. Towards evening these 

 winged atoms come forth, and creep under the clothes of the 

 inhabitants, and by their bites, produce an intolerable irritation, 

 and a momentary smarting, compared f to that caused by sparks 

 of fire. They do not draw blood, and no swelling follows their 

 attacks. They are most troublesome during the months of July 

 and August. 



The most common of our large gad-flies, or horse-flies, appears 

 to be the Tabanus airaius, of Fabricius. It is of a black color, 

 and the back is covered with a whitish bloom, like a plum. The 

 eyes are very large, and almost meet on the top of the head ; 

 they are of a shining purple-black or bronzed black color, with a 

 narrow deep black band across the middle, and a broad band of 

 the same hue on the lower part. The body of this fly is seven 

 eights of an inch or more in length, and the wings expand nearly 

 two inches. The Tabanus cinctus, of Fabricius, or orange- 

 belted horse-fly, is not so common, and is rather smaller. It is 

 also black, except the first three rings of the hind-body, which 



* " Canadian Naturalist." p. 51 . t See Gosse's " Canadian Naturalist." p. 100. 



