THE ICHNEUMON FLIES. 



497 



Parasitic Insects. 

 Cocoon, of Oak-egger Motli Cocoon from New South Wales 



iCryptusfumipenms). 



Cocoon of Puss Moth 

 (Paniscits glaucopterua). 



(1'iiitpla). 

 Cocoon of Goat Moth 

 (Lamjnosa setosa). 



ments, and then flying off again. They look very pretty, harm- 

 less creatures, but, in fact, they are doing all the harm that lies in 

 their power. Forty or fifty eggs are thus laid on a plant, and if 

 only one quarter of the number are hatched, they are quite capa- 

 ble of eating every leaf. In process of time they burst from the 

 egg-shell and commence their business of eating, which is carried 

 on without cessation throughout the whole time of the larval ex- 

 istence, with a few short intervals, while they change their skins. 

 When they are full grown they crawl away from the plant to 

 some retired spot, and there suspend themselves, preparatory to 

 changing into the pupal condition. A few of them succeed in 

 this task, but the greater number never achieve the feat, having 

 been the unwilling nourishers of the ichneumon flies. Just be- 

 fore the larva is about to pass into the pupal state, a number of 

 whitish grubs burst from its sides, and each immediately sets to 

 work at spinning a little yellow oval cocoon. The walls of the 

 cocoon are hard and smooth, especially in the interior; but the 

 outside is covered with loose floss-silk, which serves to bind all 

 the cocoons together. Generally they are very loosely connect- 

 ed ; but a group of these little objects is now before me, where 

 the cocoons are formed into a flattish oval mass, about the size 



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