22 



COLLECTING AND PRESERVING INSECTS. 



Alypia of Grape. 



Fig. 18. 



veined wings are also covered with dust-like scales. Their 

 transformations are complete. The active larvae assume a 



worm-like form with several 

 pairs (1-5) of fleshy false legs 

 besides the thoracic ones ; they 

 spin silken cocoons before 

 changing to pupae (chrysalides, 

 nymphs), with the exception 

 of the butterflies. The limbs of 

 the chrysalides are soldered to- 

 gether, and the abdomen is 

 movable upon the head and 

 thorax. 



Diptera (Flies. Fig. 18, Orta- 

 lis fly and larva) have the mouth 



parts formed into a kind of proboscis ; the second pair of 



wings are undeveloped, being reduced to a pair of pedicelled 



knobs serving as 



balancers or pois- 



ers. Their trans- 



formations are 



complete, the larva? 



being maggots or 



elongated w o r m- 



like embryos. The 



pupae often change 



within the skin of 



the larvae, which serves as a cocoon. The limbs are free. 



. Fig. 19. rig. 20. Mar >y of the species are 



aquatic. Here we first 

 find wingless parasites. 



Coleoptera (Beetles. 

 Fig. 19, Asemutn beetle, 

 a, larva, 6, pupa ; fig. 20, 

 Potato beetle) are known 

 by their hard bodies, free 

 and well developed mouth 

 parts, and by the first 



pah , 



OrtaUs an 



Asemum and young. 



Potato Beetle. 



ened into sheaths (elytra) for the protection of the second 



