220 



SUBEINGDOM AKTICULATA. 



Fig. Sie. 



eggs, side by side, with a thin layer of woody fibre between. 

 The larvae, on hatching, drop to the ground, in which they 



live for seven- 

 teen years, feed- 

 ing upon the 

 roots of trees. 

 When ready to 

 enter the pupa 

 state, they 

 make cylindrical burrows, 

 cemented water-tight, and 

 at length issuing forth, in 

 appearance like the imago 

 except the want of wings, 

 attach themselves to any 

 object at hand, particular- 



CicMa septendScim, " Seventeen-year Locust." j^ ^^^ trunks of trees. In a 



short time, the thorax splitting on the back, 

 the perfect imago crawls out ; after pairing, 

 the female deposits its eggs, and the male -^ 

 fills the air with the noise of the ear- 

 piercing kettle-drum beneath its wings.* 



Coreidae.— The Squash-bug hibernates 

 in cre^aces, but lays its eggs on the under ' 

 side of squash leaves. Tlie young brood 

 are of a pale ash color, and, after molting 

 several times, appear in their perfect state 

 with wings and wing-covers. 



A p h i d se (exhausters). — Plant-lice f 

 have a wonderful life-history. The eggs 



mg. 377. 



Careys tristU^ 

 Squash-bug. 



• This apparatus is concealed under two valves in the upper part of the 

 abdominal cavity. The membrane of the drum-head is thin, brittle, and slightly 

 wrinkled. There is a muscle attached to it on the inner side. By contracting 

 this, the drum-head is drawn in, but on relaxing, it springs back of itself, 

 thus producing the ' familiar clicking noise of the Cicada. The pupil can 

 easily make a dissection of the insect, and examine the apparatus for 

 himself. 



■f Nothing can be more amusing than to watch the plant-lice for half an hour. 



