THE BOLL WORM OR CORN EARWORM. H 



POISON I X(; COTTON. 



The use of poisons against the bollworm has met with considerable 

 success when the poisons have been applied at the proper time. 

 Attention has been directed to the fact that a large proportion (from 

 GO to 80 per cent) of the eggs deposited in cotton fields are placed 

 elsewhere than on the squares and flowers. Following hatching, 

 therefore, it is necessary for the young larvae to travel a considerable 

 distance before penetrating the fruit. During this rather aimless 

 wandering the insect eats here and there from the surface of the 

 leaves and stalks. During this short period in the existence of the 

 larva it is susceptible to the action of various arsenical poisons. 



The time for applying the poison varies slightly from year to year. 

 The first application should be made when the corn ears are becoming 

 hard. The actual date will range from about July 10 to August 

 20, according to latitude and seasonal conditions. Powdered arsenate 

 of lead or Paris green should be used. The former is less poisonous 

 to the insect but is not so apt to cause burning of the foliage. At this 

 season the slight burning resulting from the use of Paris green is 

 really immaterial. Arsenate of lead has the advantage of sticking 

 firmly to the plants; even a light rain will not wash it off after it has 

 once dried on. The poison can be applied in dust form or as a spray. 

 The former usually is more practical, since water is not usually 

 found in proximity to cotton fields, and more time is required in 

 applying poisons in liquid form. If Paris green is sprayed on, it 

 should be used at the rate of 1 pound to each 50 gallons of water, 

 and 50 gallons w^ill cover about 1 acre. The powdered arsenate of 

 lead should be used at the rate of about 5 or 6 pounds per acre, and 

 the Paris green, when used in dust form, at the rate of 2 to 3 pounds 

 per acre, according to the size of the i3lants. When Paris green is 

 used a field can be covered more economically by mixing the material 

 with two or three parts of air-slaked lime, which also lessens the 

 likelihood of burning. The poisons may be put on by the old- 

 fashioned " bag and pole " method or, better, with a power blower 

 or a hand blower mounted on a light wagon. The bag and pole 

 method is fairly efficient and obviates the purchase of machinen-. 



These outfits are not difficult of construction. A 4-inch board 

 about 18 inches longer than the distance between the rows is used for 

 the pole. To form the bags at either end, four blocks of the same 

 material, each about 4 inches long, are nailed endwise to the under- 

 side of the pole. One of these is placed at each end and the other two 

 about 16 inches from these to form the ends for the rectangular- 

 shaped bags. An inch or one and one-half inch hole is then bored 

 through the pole about 8 inches from either end for pouring the 

 poison into the bags. These Iwles are closed with corks when the out- 

 fit is in use. The sides of a rectangular piece of cloth are then tacked 



