Records were made almost daily, and the maximum temperature on the day 

 of record was taken to be the temperature affecting activity. One weevil was found 

 active on a day when the maximum temperature was only 36°F., but all others 

 were found when the temperature was 40° or higher. 



The percent of weevils recorded as active at maximum temperatures of 36° 

 to 45°, 46° to 55°, 56° to 65°. 66° to 75°, and 76° to 81°F. were 1%, 7.6%, 20.1%, 

 36.9%, and 34.4%, respectively. The average numbers of weevils found to be 

 active each day at those temperatures were 5.5, 9.5, 18.7, 23, and 62.7. The num- 

 ber of weevils found to be active during the period of hibernation was 2.65% of 

 the total number in the cages, but it is probable that some weevils died before the 

 end of February, thus reducing the total number that might become active. 



Examination of adhesive screens, situated in infested cotton fields during the 

 hibernation periods of the years 1931-35, indicated that there was no flight at 

 maximum temperatures of 62° to 65°, 66° to 67°, and 67° to 83°F., respectively. 



1935 - Hixson, E. Distribution of hibernated boll weevils in an Oklahoma cotton field. 

 J. Econ. Ent. 29(l):96-99. 



Distribution of overwintered boll weevils ( Anthonomus grandis Boh.) in a 

 heavily infested cotton field in southeastern Oklahoma, late in May and early in 

 June 1934, showed no relationship to nearness of adjacent woods. The weevils 

 did, however, tend to be more numerous in that part of the field nearest alfalfa, 

 and this tendency increased noticeably in the later examinations. Statistical anal- 

 ysis showed a high degree of negative correlation between weevil population and 

 increase in distance from the alfalfa field. 



1935 - Hixson, E., and C. A. Sooter. Freezing temperatures of the chinch bug, Blissus 

 leucopterus , Say. J. Econ. Ent. 29(2):465-466. 



B_. leucopterus had a mean freezing point of 9°F. for February and 17.5°F. 

 for March, compared with 10 and 15°F. on corresponding dates for Anthonomus 

 grandis Boh., which emerge from hibernation in Oklahoma in June. The chinch 

 bug emerged in April. 



1937 - Hixson, E., and C. A. Sooter. Temperatures at which boll weevils freeze. 

 J. Econ. Ent. 30(6):833-836. 



The cotton boll weevil is much more resistant to cold than was formerly 

 supposed. The undercooling temperatures of 991 boll weevils show a range from 

 26.6° to 9.4°F. Those undercooled in November and February were the most 

 resistant, while those undercooled in December and March were the least re- 

 sistant. Winters having low minimum temperatures were followed by small 

 field populations of hibernated weevils, whether the population the previous year 

 was large or small. 



1941 - Reinhard, H. J. Cotton insect investigations. Tex. Agr. Expt. Sta. 54:31. 



An unusually mild winter season from November 1940-January 1941 

 (minimum temperature 26°F.) followed by the heaviest boll weevil survival 

 recorded at College Station. Out of a total of 5,000 weevils installed in hiberna- 

 tion cages, 951, or 19.2%, passed the winter successfully. Total weevil emer- 

 gence from hibernation by months in 1941 was as follows: April, 3.6%; May, 9.4%; 

 June, 5.7%; July, 0.4%. In the period 1936 to 1941, inclusive, the average boll 

 weevil survival was 7.4%. 



1942 - Bondy, F. F., and C. F. Rainwater. Boll weevil hibernation, survival, and 



emergence under South Carolina conditions. J. Econ. Ent. 35(4):495-498. 



Studies on the factors that influence the abundance of Anthonomus grandis 

 Boh. on cotton, with particular reference to survival of the winter and emer- 

 gence in South Carolina. In cage tests carried out in 1931-41, only a small 

 proportion survived even the mildest winter. Temperature was the most im- 

 portant factor affecting survival, which averaged 0.21% in 4 years when the 

 minimum temperature was below 15°F. and 5.67% for 5 years when it was 19°F. 

 or above. 



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