328 INSECTS AT HOME. 



can be found adhering to twigs, and from them the insects can 

 be procured in considerable numbers. I find, on examining- a 

 series of tliese cocoon-masses, that the number of individual 

 cocoons is somewhere about one hundred and fifty. 



When the pupa changes to its perfect form, it gnaws a round 

 hole at one end of the cocoon, so as to cut out a sort of lid, by 

 raising whicli it can escape. Very often, the inverted lid is 

 left in the cut end of the cocoon and closes it. The average 

 length of the cocoon-cluster is nine-tenths of an inch, its width 

 nearly a quirt er of an inch, and the depth of cell one-tenth of 

 an inch. Tlie insects are pale and shining yellow, with the 

 upper part of the abdomen and end of the thorax black. 



We now come to the great family of the Chalcididse. 

 These insects are parasitic, are for the most part exceedingly 

 small, and many are very tiny indeed. The head is trans- 

 verse, the eyes set on the sides, and the antennae are short. 

 The upper pair of wings are almost without nervures, though 

 the course of one or two can be traced by careful examination 

 with a microscope. The lower wings have only a single nervure. 

 They are parasitic insects, many of them being actually para- 

 sitic upon other parasites, and some depositing their eggs in 

 various galls, where they feed upon the rightful inhabitants, 

 and in due time make their appearance, to the great perplexity 

 of practical entomologists who liave kept the galls for the pur- 

 pose of rearing the particular Gall-flies which belong to them. 



One of these insects, called Cleonymus inaculipennis or 

 depressus, is shown on Woodcut XXXII. Fig. 4. 



It is a very pretty little insect, the colour being a deep 

 metallic blue, changing to green and pink according to the 

 variation of the light. The antennae are red, tipped with black, 

 and the abdomen is flattened, a characteristic which gained for 

 it the name of depressus. The wings are prettily mottled 

 with brown, as seen in the illustration. Mr. F. Smith says 

 that he has often seen it running quickly about posts and rails, 

 busily engaged in prying into every orifice, probably for the 

 sake of detecting some wood-boring insect, in whose body it 

 can lay its eggs. 



In this genus the thorax is rather long and egg-shaped., the 



