74 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



EFFECT OF TIME OF ENTERING HIBERNATION AND NATURE OF SHELTER 

 UPON THE PERCENTAGE OF SURVIVAL. 



One of the most important points upon which information was 

 sought throughout these experiments was the effect of time of enter- 

 ing hibernation and nature of shelter upon the percentage of survival. 

 The first confinement of weevils in the fall occurred fully a month 

 earlier than the beginning of similar experiments the previous year, 

 and it was expected that the intervals between their confinement in 

 the cage and the time for successful hibernation might be sufficient to 

 plainly reduce the proportion of weevils surviving. 



Table XXXVII. — Chronological arrangement of sectional records showing relative 

 survival at Dallas, Calvert, and Victoria, Tex., 1906-7. 



DALLAS. 



Cliaraeter of shelter and food. 



Leaves and hay, 4 Inches deep, cot- 

 ton stalks lefto 



Leaves and hay; stalks cut and left 

 four days b 



Leaves and grass 4-5 inches deep; 

 no food 



Spanish moss and chips; c cut food.. 



Leaves and grass 2-3 inches deep; 

 no food d 



Leaves and grass 9-10 inches deep; 

 stalks cut and left « 



Leaves and grass: no food / 



Leaves 8-10 inches deep; green cot- 

 ton cut and left s 



Leaves 3-4 inches deep; stalks left 



standing 



do 



Bare ground; no food 



(Bolls i on surface j 



iBolls i buried; 



Date of 

 last 

 emer- 

 gence. 



Total and average . 



May 21 



May 6 



May 19 

 June 17 



June 15 



May 15 

 May 21 



June 19 



June 4 

 June 8 

 Apr. 29 



l-May 2 



Basis 

 number 



of 

 weevils. 



3,800 



2,090 



3,610 

 3,325 



3,135 

 3,040 



3,040 



2,565 



1,570 



975 



30,864 



Total 

 weevils 

 emerged. 



226 

 231 



250 



383 



448 



804 

 65 

 46 



3,464 



Percent- 

 age of 

 survival. 



2.61 

 4.07 



6.26 

 6.95 



12.22 



14.74 



3L34 

 A 4. 14 



4.72 



4.51 



Rank of 

 section in 



survival. 



CALVERT. 



Food, two days; grass and leaves 



4-5 inches deep 



Grass and leaves 4-5 inches deep 



Spanish moss; chips 



Food two days; grass and leaves 4-5 



inches deep 



Food dry; grass and leaves 4-5 



inches deep 



Food cut down, left dry; 10 inches 



grass and leaves 



Stalks cut downi, left dry; 2 inches 



grass and leaves 



Field protection or bare; some grass. 



No food; leaves and hay 



Bolls 



Total and average. 



June 12 

 May 30 

 July 1 



May 30 



Apr. 26 



June 12 



May 31 

 May 16 

 Jime 12 

 Mar. 24 



2,375 

 2,375 

 2,375 



2,375 



2,375 



2,375 



2,375 

 1,425 

 1,358 

 (*) 



19,408 



75 

 116 

 105 



63 



45 



438 



253 

 359 

 380 



1,842 



3.15 



4.88 

 4.42 



2.65 



1.89 



18.44 



10.65 

 25. 19 

 27.98 



9.49 



o See PI. VII, fig. 2. 

 iSeePl. Vll.fig. 3. 

 cSee PI. VIII, figs. 1,2. 

 d See PI. IX, fig. 1. 

 «See PI. IX, fig. 2. 

 /See PI. IX, fig. 3. 

 3 See PI. X, fig. 2. 



A The weevils put in on November 21 were brought from Brownsville, Tex. The low percentage of 

 survival doubtless resulted from their weakened condition, owing to insufficient food during transportation. 

 i Bolls presumably infested. 

 ;SeePl. X.fig. 1. 

 k No estimate made. 



