LABGE-CAGE EXPERIMENTS, KEATCHIE, LA., L90&-6. 



47 



At Victoria in the spring of 1904 the period of emergence from 

 hibernation was determined in the field under exceptionally favor- 

 able conditions. A severe drought, occurring immediately after 

 most o( the cotton bad been planted, so retarded germination thai 

 the sprout cotton developed nearly two months in advance of 

 the planted. Large numbers of weevils emerged before most of the 

 planted cotton was through the ground. Practically the only food 

 supply afforded these weevils was found in the sprout cotton. By 

 reducing the number of sprout plants upon a field of 65 acres it was 

 possible to examine at frequent intervals all of the plants. Since 

 all weevils found at each examination were collected and removed 

 from the field those found at the next subsequent examination may 

 be considered as having emerged in tin 4 interval. The development 

 <>f squares upon the most advanced plants was not sufficient to 

 make it possible for any weevils of the first generation to have become 

 adults before June 1. The collections from the sprout plants were 

 continued until May 26, and it is probable that some weevils emerged 

 from hibernation after this date. Our knowledge of the weevils at that 

 time was not such as to enable us to distinguish accurately between 

 hibernated and recently emerged adults after that date. For that 

 reason May 26 was considered as representing the conclusion of 

 emergence from hibernation, although it probably continued longer. 



Table XXLV.—Rclatioti of aeeumidatea ' ej/eetin temperature to accumulated emergence 

 in field observations at Victoria, Tex., in 1904- 



Periods. 



Feb. 1 28 



Mar. ! is 



Mar. L9 25.... 

 Mar. 26 31.... 

 Apr. 1 



Apr. 6 12 



Apr. 13 a... 

 Apr. I. 



Mav 2 11..'... 

 May 12 L9.... 



Accumu- 

 lated 

 effective 

 tempera- 

 ture. 



F. 



.-.os.n 

 5S5.5 

 ,117.5 

 240.0 

 ,378.5 

 ,537.0 

 ,656 

 ,104.0 

 ,374.0 

 ,584.0 

 ,814.5 



Accumu- 

 lated 

 number 

 of plants 

 of cotton 

 sprouts 

 examined. 



None. 

 250 

 i i5i i 

 1,190 

 1.72H 

 2,120 

 2.:i2i) 

 2,570 

 2,990 

 1,163 



Accumu- 

 lated 

 percentage 



of plants 



examined 



to entire 



number 



examined. 



None. 

 4.2 

 11.0 

 20.1 

 29. 1 

 35.9 

 39.3 

 13.5 

 50.6 

 70.5 

 [OH.O 



Accumu- 

 lated 

 number of 



weevils 



found. 



None. 

 19 

 39 

 05 

 100 

 L60 

 200 

 22 I 

 376 

 52] 

 648 



Accumu- 

 lated 



percentage 



Of \\"<'c\ tlS 



at each date 

 to entire. 

 number 



found. 



None 

 2 93 



6.01 



io. o: 



15. w 

 24.60 

 30. BC 

 34. 50 

 58. 0C 

 81.01 



|II().(<(1 



A comparison of Tables XXIII and XXIV shows that there was a 

 much greater accumulation of temperature at Victoria for the same 

 percentage of emergence than occurred at either Dallas or Keatchie, 

 although the Keatcbie record appears to exceed the Victoria record 

 in the amount of accumulated temperature accompanying complete 

 emergence. It seems very probable thai in the field records the 

 accumulations are excessive because of two facts; first, at each 



