HIBEKISTATION AND DEVELOPMENT OF BOLL WEEVIL. 

 Table I. — Percentage of mortality of hibernating weevils — Continued. 





Date placed in 

 cage. 



m 

 O 



m 



Date hi- 

 bernated. 



February, 1904. 



March, 1904. - 



n . 



<v 

 ^ > 



o 



0) 



> 



Lot. 



6 



6 

 > 



< 





6 

 ft 



OJ 



ft 



<v 

 ft 



1 



1903. 



October 7 



October 8 



October 16 



October 23 



October 25 



November 1 . . 

 November 9 . . 

 November 17 . 



Average . . 

 Average . . 



100 

 100 

 100 

 100 

 300 

 200 

 200 

 200 



500 

 600 







Per ct. 



Per ct. 





Per ct. 



Per ct. 



Per ct. 





a 2 





















aS 





















4 



Nov. 18 



....do... 



....do... 



do... 



2 

















5 

 « 6 



7.3 



91.6 



22 



5.6 



94.4 



5.6 



Mar. 22 









21 



24 



10.5 

 7.0 



89.5 

 93.0 



""I'.O 



Mar. 18 



8 



do ... 













....do... 











5+7 















6.2 





4,5 6 



....do... 





































a Furnished with squares for food. 



b Accidentally disturbed and discontinued. 



It will be seen from these experiments that weevils can not be forced 

 into hibernation before the temperature declines to that point at which 

 the}^ normally hibernate, and that if deprived of food or confined much 

 before that time most of them will die. The first weevils to go into 

 hibernation were those of lot 4, placed in cages on October 23, but 

 these did not actually hibernate until November 18. The case of lot 

 8, of 200 weevils placed in a cage November 17, in which all died by 

 November 25, is difficult to explain. Our notes upon the condition 

 of the weevils in the fields during the same fall show practically the 

 same conditions as those existing in the cages. The very careful 

 record by Mr. A. F. Conradi, made in fields in the neighborhood of 

 the collepe, is brieflv as follows: 



September 6, 7, abundant, very few perfect squares, dry weather; September 8, 9, 

 abundant, mating pairs common; September 10, abundant, practically all squares 

 punctured, mating pairs less common; September 11, 12, less numerous, fewer mating 

 pairs, few perfect squares; September 13, less abundant, perfect squares more com- 

 mon, mating pairs scarce; September 14, 15, less abundant, perfect squares more 

 common; September 16-18, fewer weevils, perfect squares more common; Septem- 

 ber 19, less destructive than at any time since the 10th, perfect squares abundant; 

 September 20-28, similar conditions; September 29, 30, conditions growing worse, 

 more weevils, fewer perfect squares; October 5, numerous, eating vigorously; Octo- 

 ber 10, exceedingly abundant and destructive, a few dozen perfect squares found 

 with great difficulty, smallest squares often punctured in several places; October 11, 

 abundant, several on plants near field, one in door yard on house, mating common; 

 October 12, 13, abundant, few mating, few perfect squares; October 14, many weevils 

 found clustering about the base of bolls of all sizes just inside of the involucre, no 

 signs of hibernation; October 16, 100 weevils found on 95 plants in thirty minutes; 

 October 18, 19, weevils more sluggish, unusual numbers congregate behind involucres 

 of larger squares; October 20, the size of weevils is exceedingly variable, more so than 

 at other seasons, general depression in activity; October 22, some adults mating, no 

 signs of hibernating; October 23-26, less numerous, no mating pairs, weather cool, 

 beetles seem to be leaving; November 2, abundant in certain localities in the field; 

 on 5 plants they average one to a square, then for a dozen or more none are found; 

 mating common, but little egg laying for several days. 

 9223— No. 63, pt 1—07 2 



