90 INSECT ENEMIES OF THE BOLL WEEVIL. 



especially since such jilants afford much more sunlight on the ground. 

 The ants and also the parasites prefer much more to attack the 

 squares wliich are dried out than moist squares. It seems that they 

 can more readily penetrate the hnings of the square. In addition to 

 these qualities of the cotton variety, the use of a variety with at 

 least a moderate amount of nectar is also advised. The reason for 

 tliis has been explained in preceding paragraphs. Finally, the tend- 

 ency of plants to retain the squares must be again mentioned. If a 

 variety can furnish the desired quahties of early producing, produc- 

 tiveness, and quahty of hnt, as well as a diagonal absciss layer on the 

 square, that variety should be chosen above others. 



If at all possible, it is advisable to plant the rows far apart or on 

 the check-row system, in order to give the necessary amount of sun- 

 Hght. The cultivations to follow tliis should be with the purpose 

 of obtaining a dust mulch, for with such a mulch the surface of the 

 soil may be heated to a much higher degree than by deep and lumpy 

 cultivation, and the control of the boll weevil will thus be greatly 

 increased, through the drying effect upon fallen squares. 



5. HOW TO PLAN FOR THE GREATEST POSSIBLE CONTROL. 



As it has been proven that many agricultural processes are favor- 

 able to the development and attack of parasites and enemies, there 

 can be no question but that it is desirable to plan to obtain the great- 

 est amount of this beneficial aid. 



There are a few plants which have no objectionable quahties in 

 themselves which might with good reason be planted adjacent to the 

 cotton fields in order to induce the attack of wee^als which act as 

 hosts of the boll-weevil parasites. For instance, the presence of a 

 hedge of blackberries or dewberries along the fence means the pre- 

 sence of Antlionomus signatus, the blackberry bud weevil, with its 

 numerous parasites, all of wliich attack the boll weevil. The para- 

 sites would be able to carry on a generation in the spring before the 

 boll weevils were breeding and would mature in plenty of time to 

 attack the first developing stages of the boll weevils. 



It would seem advisable to plant a hedge of the flowering shrub 

 Amorplia fruticosa, wliich is the host plant of Laria exigua. This 

 httle wevil is very abundantly parasitized. 



In planning the cropping system there can be no possible harm 

 in arranging to have a forage or hay crop adjacent to the cotton 

 field. In case a forage crop is used, cowpeas with the ever-present 

 cowpea pod weevil would undoubtedly bring about the presence 

 of several important parasites. The early removal of the cowpeas 

 for fodder would force the parasites to attack the boll weevil. In 

 the case of a hay field, the process of haying and subsequent curing 



