8 THE COTTON WORM OR COTTON CATERPILLAR. 



Powdered arsenate of lead should be applied at the rate of about 

 2 pounds per acre, more or less, depending upon the size of the cotton. 

 It is best to make the application when the leaves are moist with 

 dew, as is generally the case early in the morning. The less mnd 

 there is the less will be the loss from the poison which drifts onto the 

 ground. Therefore a calm time should be selected. 



The earlier the application of arsenicals can be made the better 

 it wall be. The planter should not wait until extensive defoliation 

 has taken place. A watch should be kept upon the low moist areas, 

 where the worms invariably appear first. As soon as the destruction 

 of the leaves becomes evident in such places the poison should be 

 applied. By this means the outbreak may be checked, and the 

 necessity of poisoning the total acreage on the plantation may be 

 avoided. 



After ])owdered arsenate of lead the best insecticide for the cotton 

 caterpillar is Paris gi-een. As has been indicated, however, even 

 small amounts of this substance are likely to injure the foliage. 

 Such injury may not become apparent until several weeks after the 

 application. Nevertheless, the burning of the tender leaves will 

 show eventually in the stunted condition of the plants. This diffi- 

 culty may be overcome to some extent by the use of air-slaked lime 

 and Paris green in equal parts. Wliether the lime is used or not, 

 flour should be used with the Paris green in equal parts. Tliis wUl 

 assist gi'eatly in causing the poison to adhere to the foliage. 



London purple can also be used, but it is much less valuable than 

 Paris green on account of the frequent occurrence of free arsenic 

 which causes burning of the foliage. 



Wliite arsenic should not be used on cotton. It will kill the cater- 

 pillars, but will burn the foliage to such an extent that it does more 

 harm than good. 



METHOD OF APPLYING THE POISON. 



The method of application by means of sacks appUed to a pole 

 carried on horseback through the fields, which came into general use 

 some years ago, will be found to be perfectly satisfactory. By this 

 means a single farm hand can poison 2 rows at a time and cover 

 about 20 acres during a day. 



The apparatus for making the apphcation is simple. A strip of 

 hardwood 3 inches in width, 1 inch thick, and 1 foot longer than the 

 distance between the rows should be selected. Two 1-inch holes 

 should be bored through the stick 6 inches from either end. The 

 sacks to contain the poison should made of 8-ounce duck or similar 

 material. Flour sacks will answer the purpose, but when powdered 

 arsenate of lead is used, two thicknesses wdll be required on account 

 of the extreme fineness of the poison. The sacks should measure 6 



