40 PROLIFERATION IN CONTROL OF BOLL WEEVIL. 



of culture wliich has boon customarily cniployGd. Many factors nuist 

 be considered in any hopeful solution of this most serious problem. 

 With insect pests ounces of prevention are worth many pounds of 

 cure. The most promisini^ solution of the weevil problem is undoubt- 

 edly found in a combination of the factors restrictmg- weevil develop- 

 ment with those favoring- crop im})rovement. The facts learned from 

 this stud}^ of proliferation may be utilized in the class of factors 

 restricting- wc^evil development. 



It appears that there is a small variation bc^tween difl'erent varieties 

 of cotton in regard to the proportion of cases in which weevil punc- 

 tures stinuilate proliferation. It is evident that the presence of pro- 

 liferation increases somewhat the percentage of mortality among the 

 larva^ and pupai in proliferating buds and )>olls. The plain conclusion 

 is that the varieties which proliferate most freely will ])y that charac- 

 teristic tend to restrain the rapid multiplication of the weevil. It is 

 probable that varieties may be developed l)v repeated selections which 

 will be more ett'ective than any now known in restraining- weevil 

 development in this wa}^; still, this factor alone will probably never 

 be of more than secondary importance in reducing- the number of 

 weevils, as other considerations will inevitably be more important in 

 determining the most desirable variety to plant. Although the obser- 

 yations thus f:ir made have failed to show an}' conclusive eti'ect of 

 fertilization of the soil upon proliferation, further investigations 

 should be made upon this point. Much work would still l)e necessary 

 to determine any constant relationship between the formation of pro- 

 liferation and climatic conditions. Probably little practical use could 

 be made of a knowledge of such climatic relationships if ascertained, 

 as the influential factoi's would always remain be3'ond the control of 

 the cotton planter. 



The tendency to proliferate is by no means a recently acquired char- 

 acteristic of cotton; therefore it should not be supposed that it is 

 an}^ more susceptible to such variation as will render it a still greater 

 obstacle to weevil development than are many other characteristics 

 which may l)e emphasized witli equal or even greater advantage in the 

 selection of new strains of cotton for growth in the weevil-infested 

 area. Such selections require much time, and we may, therefore, feel 

 somewhat encouraged to know that in the long tight yet to come we 

 may expect this natural factor to accomplish no -less than we have 

 found it now doing toward the repi-ession of the weevil. Of course 

 complete reliance can never be placed in natural factors for a solution 

 of the weevil problem. Doubtless the capacity of the weevil for adap- 

 tation to any new conditions which its food jilant may present is just 

 as great as is any adaptive capacity of the plant. Nevertheless, the 

 interference of man is likely to throw the advantage greatly in favor 



