INSECTS. 



currycomb, or by a pair of scissors. 

 When the disease is certain, one of 

 the best methods to destroy the in- 

 sect is to fasten a bag net on the 

 horse, for the purpose of catching the 

 excrement, as well as the full-fed lar- 

 vae. By throwing the dung every 

 morning into a deep pit, any larvae 

 that may be enclosed in it will thus 

 be prevented from working their way 

 to the surface when their last trans- 

 formation is about to take place, and 

 their death will cut off a numerous 

 progeny. There are other dipterous 

 insects which feed upon the blood 

 both of horses and cattle ; the most 

 formidable of these are the horse- 

 flies {Tabani, k, I); others, much 

 smaller {Stomoxys calcitrans), assail 

 him in every situation during sum- 

 mer, and dart their long probosces 

 into his legs and belly. But none are 

 more trying to him than the forest 

 fly {Hippobosca equina, L.), which runs 

 sidewise or backward, like a crab, 

 and shelters itself in those parts least 

 covered by hair : it may, however, be 

 caught by the hand when the animal 

 is in his stall ; but its substance is so 

 hard, that it can only be destroyed 

 by rolling it between the finger and 

 thumb. 



" Horned cattle are likewise sub- 

 ject to the attacks of a peculiar spe- 

 cies of gadfly (CE. bovis, d,e,f), which 

 causes them great terror and distress. 

 The larva (e) is smooth and fat, and 

 the chrysalis (/) opens by a lid (m) 

 when the insect (d) emerges from it. 

 The herdsman may know when this 

 insect appears among his flocks, by 

 the agitation they exliibit; the whole 

 herd, with their tails erect, or carried 

 in some grotesque attitude, gallop 

 about and utter loud lowings. When 

 oxen are.employed in agriculture, the 

 attack of this fly is often attended 

 with danger, as they become quite 

 unmanageable, and, whether in har- 

 ness or yoked to the plough, will run 

 directly forward. Their harness at 

 this season should, therefore, be so 

 constructed as to be easily loosened. 

 The eggs are deposited icithin the 

 skin of the animal, and in a wound 

 made by a tube resembling an auger, 



424 



with which the female is provided. 

 These flies only attack young .and 

 healthy subjects ; but, independently 

 of the terror they create, do not ap- 

 pear to occasion any material injury. 

 " Sheep are also infested by anoth- 

 er species of gadfly (CB. ovis, L., g, h, 

 i), which deposites its eggs in the 

 inner margin of their nostrils. The 

 moment the fly touches this part of 

 the sheep they shake their heads, and 

 strike the ground violently with their 

 fore feet ; at the same time, holding 

 their noses close to the earth, they 

 run away, looking about them on ev- 

 ery side, to see if the fly pursues; they 

 will sometimes crowd together in a 

 rut or dusty road, with their noses 

 close to the ground. The larvae (i) 

 are white, flat on one side and con- 

 vex on the other ; they inhabit the 

 cavities of the maxillary sinuses, 

 and crawl, when the animal is dead, 

 into those of the horns and frontal si- 

 nuses ; when full grown, they fall 

 through the nostrils, and change to 

 the chrysalis (/;), which produces the 

 fly (g) in about two months. Swine, 

 pigeons, and all kinds of poultry are 

 subject to fleas and lice of various 

 kinds, but never to such a degree as 

 to occasion death. 



'• Fish, in their young or fry state, 

 are the food of the larvse of water- 

 beetles {Dylisci). These insects are 

 frequently seen in great numbers in 

 ponds ; they may be caught by a hand 

 net (made of very small meshes), in- 

 serted beneath the insect, as he re- 

 poses (With his head downward) on 

 the surface, and then suddenly drawn 

 upward. 



" Insects injurious to Vegetables. — 

 The ravages of insects upon plants 

 commence from the time that the 

 seed is committed to the ground, and 

 continue until the produce is gatiiered 

 into the barn. We have noticed the de- 

 structive insects which are, in a great 

 degree, peculiar to certain plants, 

 as wheat, barley, &c., in a general 

 way ; we shall now enumerate those 

 that infest the grains, clover, pas- 

 tures, cabbages, and fruits, planta- 

 tions, as well as those universal de- 

 stroyers of all vegetables, the wire- 



