1 8 THE SQUASH BUG 



they undergo their second moult. After this has taken place, 

 so that the nymph is in the third of its larval stages, the body 

 is larger and flatter, with the margins more sharply defined 

 and the color somewhat darker than in the second stage. 

 The length is now about i-S inch. 



The most notable difference taken on by the insect in the 

 fourth stage, which is entered upon by the third moult, which 

 takes place about eight days after the second moult, is the 

 noticeable development of the wing pads. These now become 

 much more conspicuous than before. After living 

 in this stage for about seven days, the insect moults 

 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 (Fig. 2). The 

 wing pads are greatly enlarged, while the thorax is 



Fig. 2. Squash ^'^^"^^ ^"^ lengthened. The body is more rec- 

 Bug; stage tangular and in general becomes so similar to the 

 before adult, j^^^ J- j^jj-g ]~^^^^ ^]^^^ r^^ ^ little distance it may readily 

 Natural size. , . , <- ^1 1 t • • 1 1 



be mistaken tor the latter, it is now 1-3 inch long. 

 The full-grown nymph lives in this fifth stage about nine 

 days before the final moult by which it matures into the adult 

 squash bug, which is so familiar to every gardener that it 

 need not be described here. In the pictures on our title-page 

 the male is represented at the left and the female at the right. 



THE SqUASH BUG SINGLE-BROODED 



The squash bugs that pass the winter as adults remain in the 

 field in nearly undiminished numbers until nearly the end of 

 July. The eggs upon the leaves are more abundant during this 

 month than at any other time. Early in August, however, the 

 disappearance of the adults becomes noticeable, freshl}^ laid 

 eggs becoming more and more scarce. During August the 

 adults of the new generation become abundant, but none of 

 these lays eggs, nor even do they go through the process of 

 mating before the following spring. Consequently there is 

 but one brood of squash bugs each year. 



HIBERNATION 



When the autumn frosts blacken the leaves of the vines a 

 considerable proportion of the bugs are still immature. These 



