HEMIPTERA: THE TRUE BUGS 75 



before. After living in this fourth stage for about a week, 

 the insect molts for the fourth time, entering upon its fifth 

 stage. It is now quite different in appearance, and is 

 easily recognized as a full-grown nymph, — a condition 

 analogous to the pupa state of butterflies and moths, in that 

 it is the stage immediately preceding the adult. The 

 wing pads are greatly enlarged, while the thorax is wid- 

 ened and lengthened. The body is more rectangular and 

 so isimilar to a mature bug that at a little distance it may 

 readily be mistaken for the latter. 



The full-grown nymph lives in this fifth stage about 

 nine days before the final molt, by which it matures into 

 the adult Squash Bug. 



The Chinch Bug 



The Chinch Bug has a life history simDar to that of the 

 Squash Bug, but it does much more damage because it at- 

 tacks the great grain crops — com, wheat, oats, and simi- 

 lar staples. The areas in which it occurs in greatest 

 abundance are shown by the dots on the map below. It 

 has been estimated that during the sixty years from 1850 to 

 1 910 the losses due to this insect exceeded $300,000000. 



The full-grown Chinch Bugs pass the win- 

 ter in the shelter of thick grass, fallen leaves, 

 or other protection, and come forth in the 

 spring. They then scatter to such grain 

 crops as they can find. Here they lay their 

 eggs, one bug often laying four or five hun- 

 dred eggs. The young bugs soon hatch and chinch bug 



, . . , 1 , . ,1 Magnified 



attack the gram plants by suckmg the sap 

 through their pointed beaks. When- they are abundant, 

 they actually hide much of the surface of the leaf or 

 stalk, and of course kill the plants. 



