INSECTS. 



'• 3. Aptera. — Entomologists of the , ed and flat, is convex and thick ; the 



last century arranged all insects with 

 out wings under this order ; but it is 

 now restricted, by Latreille and Mae- 

 leay, to such only as have a bivalve 

 articulated sheatli to their mouth or 

 rostrum, and no wings, as in tliecase 

 of the common flea. - 



" 4. Hcmiptcra.— Insects of this or- 

 der are furnished with two folded 

 wings, covered by wing-cases, also 

 crossing over each other, of a semi- 

 corneous substance, and which are 

 likewise useful as organs of flight. 

 The tarsi are composed of three, two, 

 or sometimes only of one joint, and 

 the body is much flattened. The va- 

 rious insects commonly called field- 

 bugs, which emit a strong and disa- 



wings, also, instead of being folded 

 over each other, are deflexed, and 

 embrace the sides of the body. 



" The dilTerent orders of insects 

 we have now enumerated are con- 

 nected by others of an inferior ex- 

 tent, and which are called osculent 

 orders. But a description of these 

 is not essential to our present pur- 

 pose, as they do not contain any de- 

 cidedly injurious insects. 



" Insects injurious to Live Stock. — 

 The horse. The principal foes to this 

 animal are the horse-bee{CEstrus eqiii) 

 and gadfly {CE. hcemorrhoidalis). The 

 first deposites its eggs on such parts 

 of the body as are liable to be licked 

 by the tongue, and the animal thus 



greeable smell when handled, are all conveys its enemy into its stomach ; 

 arranged under this order. i the young larva? are there nourished, 



" 5. Homoptera. — T:\.\ese insects and become whitish rough maggots 

 have a great resemblance to the last ; {Fig. 1, r), which are known by the 

 but the body, instead of being depress- | name of bots. They attain their full 



Fig. 1. 



size about the latter end of May, and 

 are voided about the end of June. On 

 dropping to the ground, they find out 

 some convenient retreat, where they 

 change into a chrysalis, and in six or 

 seven weeks the fly appears. The 

 female (i) is distinguished from the 

 mal»(«) by the lengthened shape of 

 her body. The inside of the knee is 

 chiefly "selected for depositing her 

 eggs, which will frequently amount 

 to four or five hundred on one horse. 

 The other species (fB. hismorrhotdalis, 

 Lin.) is still more troublesome ; it 



deposites its eggs upon the lips, and 

 causes excessive and distressing un- 

 easiness to the animal. The pre- 

 vention of bots belongs to tlie farm- 

 er, the cure to the veterinary sur- 

 geon. The first may be effected by 

 watching the animal at the season 

 when the female deposites her eggs 



• (usually in August and September), 

 and should the horse appear much 



' agitated in its pasture, there will be 

 good reason to suspect it has been 

 attacked by the fly ; the eggs may 



, then be removed by the brush and 



423 



