HIBEENATION AND DEVELOPMENT OF BOLL WEEVIL. 38 



from the 1st of June to the 1st of September is only about fifty times, 

 certainly not over sixty-five times, where theoretically it would be six 

 hundred and twenty-five times. The reason for this discrepancy is 

 unknown to the writer, but is a fact for which the cotton planter 

 should be decidedly thankful. It may be that the mortality of the 

 immature stages of the weevil in the squares is greater than the count 

 of thousands of squares has shown, that many of the adult weevils die 

 or are destroyed before reproducing, or that the number of eggs laid 

 and the length of the period of oviposition in the field are much less 

 than those observed in the laboratory. That this is true of the hiber- 

 nated brood is shown on page 12. It would seem that the discrepancy 

 is mostly due to the two latter factors. This discrepancy but empha- 

 sizes the necessity for accuratel}^ observing the field conditions on a 

 very large scale in difierent fields in different sections of the State 

 constantl}^ thruout the season if we are to obtain accurate knowledge 

 of the true habits, rate of increase, and injury of the boll weevil, as it 

 occurs in the field. 



To summarize briefly, it would seem that if there be 2 weevils to 

 100 stalks of the hibernated brood, then by early in August there will 

 be a sufficient number of weevils to stop the blooming of the cotton. 

 Furthermore, with the normal increase it seems that in about a month 

 after 4 or 5 weevils are found on 100 stalks, there will have been suffi- 

 cient increase to prevent further fruiting of the cotton, and there will 

 then be from 75 to 100 weevils to 100 stalks. The utter impossibility 

 of making a cotton crop where a large percentage of the weevils sur- 

 vive the winter will therefore readily be seen unless exceptional meas- 

 ures can be taken to check their multiplication. Weather conditions 

 unfavorable to the development of the weevils are decidedly the most 

 important controlling factors, and that such conditions not infrequently 

 occur is shown by the reports of voluntary observers in southern 

 Texas in 1904. 



INJURY TO SQUARES IN RELATION TO THE NATURAL INCREASE OF 



SQUARES. 



The formation of squares upon the cotton plant depends upon so 

 man}^ different factors that it is exceedingly difficult to make any gen- 

 eral statements regarding the increase in their numbers. Thus the 

 character of the soil, the nature of the variety of cotton, and the cli- 

 matic conditions prevailing all influence the formation of squares. It 

 may be clearly seen from Tables VII to X that some varieties form 

 squares much faster than do others, and that between the same dates 

 the same variety will not produce the same number of squares in dif- 

 ferent places. However, from an examination of the tables we may 

 form some idea of the natural increase of the squares early in the 

 season during the critical period of fruit formation. During the 2 



