76 REPORT UPON COTTON INSECTS. 



first destroyed by the cotton-worm, it is generally believed by planters 

 that the greater number, if not all, the eggs are laid upon that part of the 

 plant. This belief gave rise to the practice 

 which has been carried on hi some localities, 

 of cutting off and destroying the terminal 

 shoots of the plant; the planters thinking 

 that in this way the eggs would be destroyed 

 and the crop saved. This idea I found to 

 be an erroneous one. Rarely eggs may be 

 found on any part of the plant above ground, 

 but almost invariably they are deposited on 

 the lower surface of the larger leaves, and 

 by far the greater number of them are to be 

 found on the middle third of the plant.* 



The eggs are deposited singly, and 1 rarely 

 found more than four or five upon a single 

 leaf, even when the moths were most abun- 

 dant; still they sometimes occur in greater numbers. The duration of 

 the insect in this state varies greatly, depending upon the season. Dur- 

 ing the warmer part of the summer months the eggs hatch in little more 

 than two days after they are deposited, but in the autumn they may re- 

 main nearly a week before the larvae issue. 



THE LARVA. 



Some time before the larva issues, it can be seen through the trans 

 parent shell of the egg, the eyes, mandibles, and V-shaped suture separat- 

 ing the epicranium from the clypeus being especially prominent. A few 

 hours later, after repeated efforts, which are plainly visible with a micro- 

 scope, the larva succeeds in breaking a hole through one side of the 

 shell, and it soon eats its way out. Occasionally the larva, as soon as it 

 emerges, eats a portion of the egg-shell ; usually, however, the shell is 

 left undisturbed. 



The newly hatched larva is of a very pale green color, or white with 

 a faint tinge of green ; the head is pale yellow, with no trace of the black 

 piliferous spots which are so conspicuous in the later stages ; the ocelli 

 are black ; the piliferous spots of the body are at first quite indistinct, 

 but soon become more prominent ; the thoracic legs and the third and 

 fourth pairs of abdominal legs are very long; the first and second pairs 

 of abdominal legs are mere tubercles. 



The young larva usually remains on the lower surface of the leaf upon 

 which the egg was deposited, feeding upon the more tender portions and 

 leaving the upper cuticle unbroken. Sometimes, however, small larvae 

 which evidently have been hatched recently are found on leaves where 

 no signs of egg-shells can be detected, while shells but no larvae are 



* For a detailed discussion of this- point and of the number of egga upon each leaf, 

 see Appendix I, report of W. Trelease. 



