ii8 The Life-History of Insects 



stage in a passive pupa-like condition enclosed in a 

 waxy cocoon (fig. 76). And in the form and habits 

 of pupge among the insects with complete metamor- 

 phosis the greatest divergence can be observed (2, 



71, 72). 



Forms of Pupae. — The pupa among Beetles 

 (fig. 69), Lacewing flies and Caddis-flies, Ants, Wasps 

 and Bees for example, shows in many respects the 

 characters of the perfect insect. The 

 appendages of the head and the legs, 

 though lying closely pressed to the 

 body, are free and easily recognis- 

 able ; the wings, though very small 

 as compared with those of the im- 

 ago, hang like flaps from the thoracic 

 segments. Such a pupa is distin- 

 guished as free. Some free pupje 

 do not remain passive throughout 

 the term of their existence. The 

 pupa of a Gnat, though usually 

 floating passively at the surface of 

 the water, can dive to escape danger. 

 The pupa of a Snake-fly, just before 

 the final moult, regains its activity 

 and runs about ; while the Caddis- 

 fly pupa, in preparation for its 

 vol. iCU.s.Dept.Agr.). change into the perfect insect, bites 

 its way out of its sunken protective dwelling-place and 

 swims through the water to escape into the upper air. 

 The pupae of the more primitive Moths closely resemble 

 those of Caddis-flies. On the other hand, the pupse 

 of the vast majority of Moths (fig. 77), of Butterflies 

 and of two-winged Flies have the limbs and wings not 

 merely pressed closely to the body, but immovably 

 fixed thereto by a general hardening and fusion of 

 the outer skin. Such pupae are distinguished as ohtect. 



Fig. 76. — Pupa of male 

 Scale - insect (Icerya). 

 Magnified 15 times. 

 From Riley.Insect Life, 



