398 



THE GIANT ICHNEUMON. 



In the genus Citnbex, of which an example is given in the illustration, the larvse possess 

 twenty-two feet, and have the power of discharging a translucent greenish fluid from certain 



pores placed on the sides of 

 the body just above the spir- 

 acles. This feat they can 

 repeat six or seven times in 

 succession. When they have 

 eaten their way to the next 

 stage of existence, they spin 

 a cocoon of a brownish color 

 and of a stringy, tough con- 

 sistency, and either suspend 

 it to the branches of a tree 

 on which they have been 

 feeding, or hide it under 

 fallen leaves. In this cocoon 

 they remain for a compara- 

 tively short time, and then 

 emerge as perfect insects. 



The terrible Turnip-fly 

 (Athalia centifolice) belongs 

 to this family. The larva of this species is popularly called the Nigger, on account of its 

 black color. Our engraving shows the insect in both its stages of development. A very small 

 species of Athalia is called Athalia spinarum. Its larva feeds upon the various cabbages, 

 eating away the whole of the soft green parts of the leaves, and only rejecting the thick 

 nervures. It makes no cocoon, but retires into the ground, excavates a kind of oval cell, 

 which it lines with a slimy substance, and there awaits its final change. 



The well-known black Gooseberry-fly (Nematus grossuldrice) is another of the Saw- 

 flies. Its larva, so destructive to the fruit, is blackish-gray. These tiresome creatures are 

 often seen in great numbers, more than a thousand having been taken on a single goose- 



Cimbex femor&ta. 

 Rhymi persuasdria. 



Urocems gigas. 

 Mine union grossdri us. 



TURXIP-FLY.— Athalia centifolice. (Natural size.) 



berry-bush, and there are two broods in the course of a year. Without going into further 

 details, it is sufficient to say that there is hardly a plant without its especial Saw-fly, and 

 that any one who can discover a really effectual mode of checking their ravages, will confer 

 no slight benefit on mankind. 



The fine insect in the illustration at top of this page, which is known by the name of the 

 Giant Ichneumon (Ichneumon grossdrius), is an example of the next family, in which the 

 ovipositor is converted into a gimlet instead of a double saw. With this powerful instrument, 



