HISTORY OF INSECTS. 7 



devastation : they are generally small insects, with slender 

 bodies, and have four transparent wings : they are very ac- 

 tive, running about the stems and leaves of plants in search 

 of catei-pillars, and fly very readily. The ichneumons are 

 of many kinds : more than a thousand species have been 

 described by naturalists ; and it is probable that every but- 

 terfly, and every moth, indeed, almost every insect, has one 

 peculiar to itself: the history of them all is nearly similar. 



The caterpillar of the tiger-moth is one of the most de- 

 structive ; it devours, indiscriminately, lettuces, radishes, 

 beans, peas and every other early production of om* gardens, 

 and is most abundant in the spring, when these plants 

 ai'e being reared : it is a very rough, hairy caterpillar, black 

 above, with a red fringe on each side, and is preyed on by 

 several ichneumons. The largest ichneumon {Pimpla 

 Instigator) of the tiger-moth {Arctia caia) is often about an 

 inch long, but varies much in size ; it has a black body and 

 red legs, and emits a remarkably strong smell, something 

 like burning pitch. In the spring, this ichneumon may be 

 seen coursing over the leaves of lettuces, nettles and currant- 

 bushes, on strawbeny-beds, &c., hunting for the object of its 

 attack. When it has found a catei'pillar, it seizes it behind 

 the head with its jaws ; at this operation the catei'pillar 

 loosens its hold of the plant on which it was feeding, rolls 

 itself suddenly into a ring, erects its bristles as stiffly as pos- 

 sible, and falls to the ground : if the fall is great and among 

 twigs, the ichneumon is sometimes dislodged, but this rarely 

 happens. 



The female ichneumon has three bristles at its tail ; the 

 middle one of these appears to be a tube for conveying its 

 eggs into the body of the caterpillar, and is called an ovi- 

 positor, the outer ones seem to serve as protectors to this 

 ovipositor, and not to be used for piercing the catei'pillar. 

 When the caterpillar can fall no farther, is frequently un- 



