possible precautions should be taken in cotton cultivation, such as to reduce the 

 cotton acreage where the necessary labor for cultivation and weevil control is not 

 available, change of crops in a planned rotation, increase of the nitrogen content 

 of the soil by growing leguminous crops, deep preparation of the soil, selection of 

 an early variety of wilt-resistant cotton, and the maintenance of a uniform date 

 for planting. 



The weevils themselves may be controlled by many mechanical devices, 

 such as the chain drag or cultivator, handpicking when squaring begins, destroy- 

 ing infested squares, and collecting the insects with a loop and bag apparatus. 

 The cotton should be promptly harvested, and the best seed for weevil resistance 

 should be carefully selected, after which all green cotton should be destroyed as 

 early as possible to deprive the adult insects of their food supply. 



To be effective, this stalk destruction should be done a month before the 

 frosts and should be effected by burning and not by the old fashioned grazing 

 method. The stalks may be cut just below the surface of the soil, piled in rows 

 and burned as soon as the leaves are dry enough, the adult weevils and all imma- 

 ture stages being destroyed in this way. Another method of stalk destruction is 

 that of deep ploughing in early autumn, a stalk bender being used to lay the stalks 

 flat upon the ground, so that the following ploughshare completely buries them at 

 the bottom of the furrow. 



The principal factors in the natural control of A. grandis are: (1) climatic 

 conditions, especially heat and drought in summer, which caused a mortality of 

 25%; (2) predaceous insects, primarily fire ants, which destroy 16%; (3) plant 

 proliferation, that is, the rapid growth of new cell tissue after an injury often re- 

 sulting in the crushing of the newly laid eggs, 12% of these thus being destroyed; 

 (4) parasites, which, however, are not to be depended on, as they destroy only 

 4%. The help of birds is a welcome, but not a dependable natural factor in boll 

 weevil control. 



Two other weevils often mistaken for A. grandis are the cocklebur weevil 

 ( Bar si transversa Say), which breeds in cocklebur, and the ragweed weevil in 

 ragweed. 



1919 - Pierce, W. D, 1. A program for the eradication of the Mexican cotton boll weevil. 



2. The need of immediately eradicating the imported European corn borer and a 

 definite proposal therefor. Gage-Pierce Res. Lab. B. 1:3-14. Dec. Denver. 



In view of the extensive annual loss incurred by the ravages of the Mexican 

 cotton boll weevil, a definite working basis is proposed with the Gage-Pierce 

 Research Laboratory as the initial unit for organizing the campaign. The plan 

 suggested involved 10 years' work of preparation for one year of absolute ces- 

 sation of cotton growing in the Southern States from New Mexico to Virginia. 



Funds subscribed for this purpose are to be kept as a trust and used only in 

 connection with activities legitimately lying within the scope of the project. 



As soon as the approval of Congress is obtained, the support of organizations 

 of growers, businessmen, and scientific men is to be sought. The officials of the 

 American Assoc, of Economic Entomologists are in sympathy with the movement, 

 and it is hoped that the Association will actively support the project when the 

 plans have been definitely laid before it. Various committees are to be appointed, 

 including those for direction, finance, legislation, demonstration, and inspection; 

 and the first duty of these will be to devise the requisite methods of attack. 



A definite plan has been drawn up on which the preliminary committees may 

 build their discussions; this plan is given in detail. 



1920 - Conner, A. B. Entomological work. Tex. Agr. Expt. Sta. 33d Ann. Rpt., p. 18-20, 



1 fig. Coll. Sta. 



A brief account of the measures against various insect pests during 1920. 

 Burning sulphur in the fields at night proved useless in the control of A_. grandis . 



120 



