38 The Bulletin. 



is well shown in Fig. 14. As injury on cotton begins to be serious 

 in August, any treatment for the purpose of poisoning the worms 

 should be made early in August so as to kill the young larvae while 

 they are feeding on the leaves, before they get in the bolls, where it 

 would be impracticable to reach them effectively. 



Natural Enemies.^-As the Boll-worm spends much of its time 

 inside the part of the plant which it attacks, it is not so often at- 

 tacked by enemies as we could wish. There is a parasite which at- 

 tacks the eggs, and which Professor Quaintance says sometimes de- 

 stroys 50 to 75 per cent of them. The fact that the Boll-worms some- 

 times eat each other has already been mentioned. Birds also no doubt 

 devour a considerable number. 



Summary. — The Boll-worm attacks many other crops beside cotton 

 and becomes noticeable as a cotton pest only in the latter part of the 

 season. They cause young squares to flare and drop, and also bore 

 into and ruin the growing bolls. It has long been present in the 

 State and is usually not very destructive to cotton, but in 1907 did 

 considerable injury. 



J J REMEDIES. 



Cultural Methods. — It has been pointed out that Boll-worm injury 

 to cotton is not serious until late in the season, hence if the cotton 

 is very early it may practically have its crop made before the Boll- 

 worm injury reaches its height. Whatever can be done to hasten the 

 crop will tend to decrease the injury by Boll-worms. Good prepara- 

 tion, early planting, use of early maturing varieties, frequent culti- 

 vation, all these things tend to force the crop along rapidly so that a 

 good crop will be assured before the Boll-worm becomes destructive. 



As we have learned that the insect passes the winter in the pupa 

 stage in the soil, a thorough breaking of the land in winter will de- 

 stroy many of the pupae by exposing them to birds and weather. It 

 has been proved that most of the Boll-worm pupae which are thus 

 disturbed in winter are killed. 



Dusting With Poison. — As the Boll-worm begins to be destructive 

 to cotton early in August, and as the young larvae feed to considera- 

 ble extent on young squares and leaves before they actually enter the 

 bolls, it is possible to poison the cotton about the first of August 

 so as to kill them. For this purpose the use of dry poison applied as 

 dust seems the "best, and Paris Green is recommended. It may be 

 applied pure or mixed with an equal quantity of flour or dry air- 

 slaked lime, but should be applied at the rate of from 2 to 3 pounds 

 of the green per acre. If mixed with equal quantity of lime, use from 

 4 to 6 pounds of the mixture to the acre. It is easier to make a uni- 

 form and economical application when the poison is mixed with some 

 other substance than to apply the Paris Green alone. 



