28 



PAPERS ON THE COTTON BOLL WEEVIL^ ETC. 



injury done depends upon the abundance of these broods, which 

 depends largely upon the time of appearance and also upon the relative 

 abundance of the hibernating brood. 



MORTALITY OF SUMMER BROODS. 



The mortalit}^ occurring in summer and fall broods may properly 

 be distinguished from that among weevils which hibernate, for in the 

 summer the greatest mortality occurs in the immature stages. The 

 number of weevils developing from squares in which eggs have been 

 laid is shown in Table IV. 



Table IV. — Percentage of u-eevils from infested squares. 



Lot. 



Date. 



Where picked and how kept. 



Number 

 of squares. 



Per cent 

 emerged. 



Weighted 

 per cent 

 emerged. 



10 

 11 

 12 

 13 



May —,1902 



July 8, 190-1 



Sept. 10, 1903 

 Sept. — , 1903 

 Sept. 21,1903 



Picked from ground; placed in cloth bags 

 and kept in laboratory under dry condi- 

 tions 



Picked from ground: kept under fairly 

 normal conditions 



do 



.do 

 .do 



11, 250 



28.5 



1,522 



39 



675 



30 



350 



34 



377 



23 



23.5 



Total of lots 2, 3, 4, and 5 . . 

 Total of lots 1, 2, 3, 4, and 5 , 



2,924 



14,174 



Sept. — , 1903 

 Sept. 21,1903 



Picked from plants; a kept on moist soil 



Picked from ground; kept between shaded 



rows 



...do 



do 



Total of lots 7 and 8 



Total of lots 6, 7, and 8 



July 15,1904 Picked from ground, under screen; placed 



I in part sun 



Sept. 11, 1903 [ Picked from ground; placed in sun 



Sept. 22,1903 Picked from plants;" placed in sun ^. 



Sept. 11,1903 Picked from ground; placed in sun 



Sept. 21,1903 Picked from plants; a placed in sun 



Total of lots 9, 10, 11, 12,13. 



162 



200 

 43 



40 



39.5 

 30 



243 



405 



400 

 210 



68 

 354 



91 



9.0 



2.3 



2.9 







1.1 



1,123 



34.3 

 25.7 

 40 



37.8 

 38.7 



9.0 



1.1 

 3.9 



a Picked from plants when squares would drop off by touching them. 



Lot 1 is based upon the following note made b}^ Mr. Wilmon 

 Newell. During May, 1902, Professor Mally gathered infested squares 

 in fields along the Brazos River below Wellborn. About 1^ bushels 

 of these squares were brought to College Station, sewn up in cheese-cloth 

 sacks, and weevils allowed to hatch. June 15 the weevils were picked 

 out and by careful measurement there were 115 c. c. of them, and 15 

 c. c. contained 345 weevils, or 1,763 weevils to a bushel. Subsequently 

 we have found about 7,500 squares in a bushel, thus indicating that 

 only about 23.5 per cent produced weevils. The squares were kept 

 in the laboratory in a diy place, and the lack of moisture may proba- 

 bly account for the low^ percentage producing adults. In another 

 test 2,924 squares gave a weighted average of 34 per cent producing 

 weevils. These were picked up and kept under fairly normal condi- 



