620 



TEXT-BOOK OF ENTOMOLOGY 



FK;. 567. Cocoon 

 (natural size) of Do- 



larvae of the Neuroptera and Coleoptera creep out of the water, and 

 by the movements of their bodies make a rude earthen cell in the 

 bank, while that of Donacia spins a dense, leathery 

 cocoon (Fig. 567) in the earth. The larvae of the 

 Embiidae are protected by a cocoon, which they 

 renew at each moult. Coiiiopteryx spins an orbicu- 

 lar cocoon, the Hemerobiidae a spherical, dense, 

 whitish one. The Trichoptera transform within 

 their larval cases, which thus serve as cocoons, 

 as do certain case-bearing Lepidoptera, notably the Psychidae. 

 The pupa of certain leaf-eating beetles (Chrysomelidae), as well as 



the Coccinellidae, Dermestidae, 

 Hister, etc., are usually protected 

 by the cast larval skin, which is 

 retained, forming a rude shelter. 

 While many beetles spin an oval 

 cocoon (Gyrinus, Silphidae), the 

 wood-boring species make one of 

 chips glued together, and that of 

 Lucanus, which feeds on decayed 



Fm. 568. -Cocoon and larva of Lucanus ^ QQ ^ ig Hned with gilk ^ {g 



568). Anobium constructs a 



silken cocoon, interweaving the fine particles of its thin castings; 

 the larvae of weevils also usually spin silken cocoons. 



]. ;,. ,-,;<) Larva (a), puparium (5), and imago (c) of Sarcoph- Fir,. 570. a. Era* 



aga, enlarged. tnnli ; b, pupa. After 



Kilt'v. 



The larval skin of the coarctate Diptera is retained as a protection 

 for the soft-bodied pupa within, the old larval skin separating from 



