74 



THE MOSQUITO AND ITS FRIENDS. 



We now come to that terror of our equine friends, the Horse 

 fly, Gad, or Breeze fly. In its larval stato, some species live in 

 water, and in damp places under stones and pieces of wood, 

 and others in the earth away from water, where they feed on 

 animal, and, probably, on decaying matter. Mr. B. D. Walsh 

 found an aquatic larva of this genus, which, within a short time, 

 devoured eleven water snails. Thus at this stage of existence, 

 this fly, often so destructive, even at times killing our horses, is 

 beneficial. During the hotter parts of summer, and when the 

 sun is shining brightly, thousands of these Horse flies appear 

 on our marshes and inland prairies. There are many different 

 kinds, over one hundred species of the genus Tabanus alone, 

 living in North America. Our most common species is the 

 "Green head," or Tabanus lineola. When about to bite, it set- 

 tles quietly down upon the hand, face or 

 foot, it matters not which, and thrusts its 

 formidable lancet-like jaws deep into the 

 flesh. Its bite is very painful, as we can 

 testify from personal experience. We were 

 told during the last summer that a horse, 

 which stood fastened to a tree in a field 

 near the marshes at Rowley, Mass., was 

 bitten to death by these Green heads ; and 

 it is known that horses and cattle are occa- 

 sionally killed by their repeated harassing 

 bites. In cloudy weather they do not fly, and 

 they perish on the cool frosty nights of September. The Timb, 

 or Tsetze fly, is a species of this group of flies, and while it 

 does not attack man, plagues to death, and is said to poison by 

 its bite, the cattle in certain districts of the interior of Africa, 

 thus almost barring out explorers. On comparing the mouth- 

 parts of the Horse fly (Fig. 71, mouth of T. lineola), we have 

 all the parts seen in the mosquito, but greatly modified. Like 

 the mosquito, the females alone bite, the male Horse fly being 

 harmless, and frequenting flowers, living upon their sweets. 

 The labrum (Z6), mandibles (m) and maxillae (mx), are short, stiff 

 and lancet-like, and the maxillary palpi (nip ; a, the five termi- 

 nal joints of the antennae) are large, stout, and two-jointed. 

 While the jaws (both maxillae and mandibles) are thrust into 

 the flesh, the tongue (Z) spreads around the tube thus formed by 

 the lancets, and pumps up the blood flowing from the wound, by 



71. Mouth Parts of 

 Tabanus. 



