The Birmingham age-herald., 1912-02-23
CLIMAT TIE HAS EFFECT IN
 RETARDING BOIL WEEVIL
BY WALTER HARPER

Washington, February 20.-(special.)- That climatic and other conditions have eome retarding effect on the progress of the cotton boil weevil in the south ern states is shown by bulletin just issued from the department of agri- culture.
 It is shown that the caterpillar, which Hid considerable damage last year to the cotton foliage in Alabama, prevent nd the spread of the more persistent pest. Drouth, freeze and other condi- lions also have their effect.
 The bulletin is by W. D. Hunter, in charge of southern field crop insect invese.g ation. MT. Hunter says:
 During the season of 1911 the boil weevil was greatly reduced in num- bers throughout its entire range. This resulted from a combination of climatic influences extending over a period of about three years. So unfavorable were the conditions that the insect was ex terminated fin an area covering about 23.O0O squaresmi1es in the northwestern portion of Texas and the western por- z tion of Oklahoma. Undoubtedly these conditions. had important bearing
 
 1911. The unfavorable conditions for the weevil which culminated in 191i began in 1909. In that year drouth oc- cured in Texas and Louisiana at such time to check the development of the immature stages. In 1910 equally adverse conditions prevailed and the pest was further reduced in numbers At the end of the season of 1910 con ditons arose which gave the insect another very important setback This was a killing frost which occurred De- tober 20. The weevils were deprived of their food in all parts of the infested territory except along the gulf coast and in few isolated localities else where. The freeze destroyed outright enormous numbers of the weevils which were found in the bolls and squares, but the conditions immediately follow ing the freeze were even more import ant in reducing the infestation to a very low point. After the freeze of October 29 the weather became warm and this induced activity on the part of the weevils that survived. In fact, temperatures occurred for several weeks which caused the insects to re- quire food. An active search for food begun, but as the cotton had all been killed the majority of the weevils which had survived the freeze could find no food and perished.
 "The general effect of the cold of Oc- tober % is shown by a study of the conditions in certain localities which were exempt from freezing temporal tures In several counties in the vicinity of Cisco, Tex for some unexplained reason, the first killing frost in 1910 did not occur until November 20. At this time most of the weevils were in hibernating quarters As a result. in 1911, it was found that in the vicinity of Brownwood there was an area in which the weevils were n,l- merous and in which considerable dam age was done This area corresponded exactly with the area in which the freeze of October 29 not experienced.
 "The great reduction in the number of weevls which succeeded in passing the winter of 1910-11 is shown by hiber- nation experiments which were conducted at Tallulah. La. At this place it Is de- termned that one half of 1 per cent of the weevils which entered Information emerged in the spring of 1911. In favor able seasons as high as F per cent have survived in that locality and. in fact the average survival during seven diff ferent seasons in seven widely separated localities in Texas and Louisiana has been per cent
 .The region in which the boil weevil became eXterminated in 1911 is the one fin which the conditions of drouth were most intense in 1909 and 1910 and in which at the same time the conditions for hi- bernation arc less favorable than in other parts or the cotton Deit. ne terrltory where the loss occurred consists gen erallv of open country in which but lt- tie timber is to be found.
 Notwithstanding the great reduction in the numbers of the boil weevils in the United States in 1911 considerable ad- vance was made to the east and north when the dispersion movement began In August The explanation of this lies in the outbreak of the cotton caterpillar. which defoliated practically all of the fields throughout the infested area at about the time the dispersion movement was beginning. The weevils started on