INSECT PESTS 39 



lead arsenate, is recommended for the purpose of 

 lessening the injury caused by the boll-worm. As 

 soon as it is noticed that the moths are becoming 

 numerous in the cotton fields, an application of the 

 poison should be made and should be repeated a 

 week or ten days later. Special care must be taken 

 to distribute the poison as far as possible over all 

 parts of the plant. One method of treating the plant 

 is to mix the Paris green with water in the proportion 

 of one pound to fifty gallons of water and apply it 

 by means of a spraying machine. Another method is 

 to dust the poison on the plants in quantities of 

 about two or three pounds per acre. The powder is 

 placed in a bag of some material which will allow a 

 certain amount to fall through as dust when the 

 bag is shaken. It should be borne in mind that the 

 poison must be employed cautiously as an excess 

 may cause injury to the plants . This plan of attempt- 

 ing to poison the boll-worms is not very commonly 

 adopted in the United States as so many of the 

 insects escape by being hidden in the bolls. Never- 

 theless, when the pest is abundant and the trap-crop 

 method has been neglected during the early part of 

 the season, the application of Paris green or lead 

 arsenate may save the crop from being entirely 

 destroyed. 



The Egyptian cotton boll-worm (Earias insulana) 

 is smaller than the American insect but produces a 

 similar effect. This pest has caused much damage 

 to the cotton crops in Egypt and Northern India, 

 and has also produced injury in Northern Nigeria. 

 An allied species (Earias fabia) has been observed 

 in India, Ceylon, and Java. In India, the use of 



bhindi " (Hibiscus esculentus] as a trap-crop has 

 proved beneficial for both species of Earias. 



The pink boll- worm (Gelechia gossypiella) causes 

 great damage to cotton by attacking the seeds in 

 the boll. It is widely distributed in Europe, Asia, 

 and Africa, and has long been a destructive pest 

 in India. A few years ago, the occurrence of the 

 insect was observed in Egypt, where it multiplied so 

 rapidly that in 1913 it caused severe damage to the 

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