The numbers of weevils that survived in cages were considerably higher in 

 trash from the woods, and lower in maize stalks than in Spanish moss, and higher 

 in cages in the woods than in those in the open fields. The average survival of 

 weevils placed in the cages in the open field on November 15th was more than 

 twice that of those installed on October 15th, showing the value of early destruc- 

 tion of cotton stalks. It compells the -weevils to enter hibernation early and in a 

 weakened condition owing to lack of food. 



Spanish moss hanging from the branches of trees near cotton fields from 

 1928 to 1938 was regularly examined each autumn to determine the relative num- 

 ber of weevils that hibernated in it. It was examined each spring to find the pro- 

 portion of weevils that survived the winters. Comparatively large numbers 

 hibernated, and temperature was an important factor affecting survival. Of 

 weevils found in the moss in spring, 70.2% and 0% were alive after winters with 

 lowest minimum temperatures of 23° and 2°F., respectively. In systematic 

 examinations begun in 1937-38 to determine the number of weevils hibernating 

 in trash in woods, 78% of the weevils found were within 50 ft. of the edges of 

 woods bordering cotton fields and practically none more than 150 ft. from the 

 edges, indicating the usefulness of burning large areas of woods for weevil 

 control. 



It is considered that correlating the results will give a more reliable index 

 of probable abundance than was obtained from examinations of Spanish moss. A 

 study of the period when weevils emerged from natural hibernation and entered 

 the cotton fields was made each year from 1938 in an isolated trap plot of early 

 planted cotton. Each plant was examined at least 3 times a week from the time 

 the cotton was large enough for weevils to feed on until July 1. Every weevil was 

 counted and killed, and every square that formed was removed so that no new 

 weevils could develop. Approximately 88% of the total emergence occurred in 

 June; about 46%, in the second half of the month. Mopping the cotton with sweetened 

 poison is not effective control after squares are large enough for the insects to 

 feed on. Since such squares are usually available by June 15 in this district, and a 

 large emergence occurs later, this method of control is quite unreliable. 



1943 - Reinhard, H. J. Hibernation of the boll weevil. Tex. Agr. Expt. Sta. B. 638. Aug. 



Weevils do not enter true hibernation when they first seek fall shelter. They 

 may remain more or less active during warm spells in the winter and may leave 

 sheltered areas. 



Among factors influencing the extent of weevil mortality, minimum tempera- 

 ture was most important. From 6% to 19% of the population survived when mini- 

 mum was not below 25°F. When minimum ranged from 17° to 0°F., less than 

 2% survived. The average survival at College Station (1925-1942) was 6.04%. 

 Mortality among weevils caged prior to October 15 was nearly 3 times greater 

 than that recorded for installations made at subsequent dates. Emergence begins 

 when temperatures reach 55° to 60°F. After emergence is definitely under way, 

 rainfall has important influence on the rate at which boll weevils leave shelter. 

 Frequent well distributed showers followed by warm sunshine favor maximum 

 emergence. During the 18-year period, 50% emerged by May 15. 



Percentage of weevil survival has no direct relation to extent of plant 

 injury. 



1950 - Bondy, Floyd F., L. C. Fife, R. L. Walker, and C. E. Jernigan. Boll weevil 

 emergence from hibernation. S. C. Agr. Expt. Sta. 63d Ann. Rpt., 72 p. Dec. 

 Over a 12-year period, approximately l/4 of the weevils emerged from 

 hibernation before June 1, or before the fruiting of the cotton plant; 3/4 emerged 

 after June 1, or after squaring of the cotton plant began; and 1/3 emerged after 

 June 14, or after blooming began. Therefore, 3 early season applications of 

 insecticide at 7-day intervals, beginning at squaring or 7 days after squaring, will 

 not kill all the overwintering adults. For this reason, it is likely that 3 or 4 addi- 

 tional applications of any insecticide will be necessary for good seasonal control. 



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