CHAPTEE X 



REMEDIES: MEANS OF COPING WITH THE INSECT: SUB- 

 STANCES USED FOE ITS DESTRUCTION. 



In this chapter Tre shall treat of remedies against the insect, but 

 more particularly of methods and principles and of substances that may 

 be used for its destruction. Mechanical contrivances and machinery 

 for the proper application of the remedies will be considered in subse- 

 quent chapters; for while it is not always easy to discuss a remedy with- 

 out including the means of its application, yet this classification of the 

 matter of the report has been found most expedient. 



DESTRUCTION OF THE EGGS, CHRYSALIDES AND MOTHS. 



Destruction of the eggs. — The exact knowledge of the natural 

 history of any injurious insect enables us to recognize its vulnerable 

 points, and to indicate those stages in which it may be dealt with most 

 effectively and most economically. The eggs being laid singly on the 

 under side of the leaves, and being, moreover, hardly perceptible, from 

 their small size and x)rotective color, it is at once apparent that every 

 attempt to mechanically destroy them in large numbers must be fruit- 

 less. Topping the cotton, as a means of destroying the eggs, is, as we 

 have already shown, of little avail at the most critical period. Experi- 

 ence has shown that the vitality of the egg is not destroyed by the ap- 

 plication of a moderate quantity of insecticides of any description. Mr. 

 Stelle reports that ^'London purple has destroyed and prevented the 

 hatching of the Aletia eggs" to which it was applied three days previ- 

 ously, and numerous experiments proved that kerosene also, when 

 brought in contact with the egg, will destroy it. However, in order to 

 destroy the egg, both London purple and kerosene have to be applied in 

 such quantities as to be injurious to the plant. 



Destruction op the chrysalides. — The chrysalis of Aletia, more 

 or less perfectly protected by leaf and web, affords little chance for its 

 successful destruction. The destruction by crushing or otherwise of 

 any chrysalides observed early in the season ought not to be neglected, 

 but later in the season, when they abound, they cannot thus be econom- 

 ically destroyed. There are, however, periods when the extensive de- 

 struction of the chrysalides would seem practicable. Whenever a field 

 of cotton has been defoliated, the worms web up thickly in the sur- 

 rounding weeds and brush, which may then be cut and burned. This 

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