10 MISC. PUBLICATION 3 5, IT. S. DEPT. OF AGRICULTURE 



Then there are other insects that cut their way into the infested 

 flower buds and eat up the soft-bodied little creatures found there. 

 The most important of these insects that eat the boll weevil are 

 certain kinds of ants. These ants seek out the- infested buds while 

 they are still hanging on the cotton plants. When such a bud is 

 found, the ant promptly gnaws through the flower-bud wall and 

 feasts upon the juicy grub inside. Often a very large part of the 

 boll-weevil grubs and pupsB in a cotton field are destroyed in this 

 way. 



The most effective way, however, that nature helps man to control 

 the boll weevil is by means of heat and cold. Very hot weather and 

 very cold weather are even more distressing to a weevil than they 

 are to us. A very cold winter followed by a bright, hot summer 

 will generally stop the weevils from increasing to numbers large 

 enough to do serious damage to our cotton crop. On the other 

 hand, if the winter is mild and the summer is wet and cloudy, we 

 may expect large numbers of weevils and much damage. 



HOW TO FIGHT WEEVILS WITH POISON 



It is not well for us to depend upon nature to do all the controlling, 

 because we never can tell exactly what the weather will be during 

 the cotton-growing season. It is too uncertain to depend upon 

 temperature and dryness, and so we have tried hard to find some- 

 thing that would help us to protect our cotton. In all the years 

 since the people of the Cotton Belt began to realize how much 

 damage the weevil could do, we have tried to find some way of 

 killing the boll weevil. Every kind of machine or poison that could 

 be thought of has been tried, but without any great success until 

 about 10 years ago. 



In 1914 field agents of the Bureau of Entomology, a division of 

 the United States Department of Agriculture, which studies insects, 

 began experimenting with a white, powdery poison known as calcium 

 arsenate or arsenate of lime. This they dusted evenly on the cotton 

 plants during the early morning while clew was still on the leaves and 

 buds. Xow full-grown weevils, besides feeding on the cotton plants, 

 drink the dew that settles there. When the weevils came to feed 

 and to drink after the plants had been dusted, each one of them 

 swallowed a tiny portion of the poison and died. 



This encouraged the field agents in their work, and a few days 

 later they dusted the plants again. After this they found that more 

 weevils had died, and so they felt they were on the right track in 

 destroying the weevils. A third dusting was finally given, and then 

 it was found that there were many more blooms in the field than 

 when dusting was started. This meant to the agents that the weevils 

 were being killed off faster than they could damage the new blooms 

 by laying eggs in the flower buds/ 



The agents felt then that they had at last found something that 

 would protect the cotton from too great a damage. They thought 

 that if the weevils did not become too numerous later a good crop 

 of cotton would be produced. So their field was carefully watched 

 throughout the summer, and whenever the weevils appeared to be 

 ting thick again another dusting of the calcium arsenate was 

 When fall came there was a good crop of cotton in 



