. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 112 THE MEXICAN COTTON-BOLL WEEVIL. Converted into terms of the number of weevils in every thousand which would survive the winter if stalks were destroyed on a given date, we can see the force of Table XLVL It is even more evident from the arrangement of the data given below in Table XLVII. Table XLVII.—Number of boll weevils in each 1,000 which would have survived destruction of stalks on a given date. Date of destruction. In Loui- siana. September 16-30 October 1-15 October 1( November November 1
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 112 THE MEXICAN COTTON-BOLL WEEVIL. Converted into terms of the number of weevils in every thousand which would survive the winter if stalks were destroyed on a given date, we can see the force of Table XLVL It is even more evident from the arrangement of the data given below in Table XLVII. Table XLVII.—Number of boll weevils in each 1,000 which would have survived destruction of stalks on a given date. Date of destruction. In Loui- siana. September 16-30 October 1-15 October 1( November November 16-30. December December RELATION OF SHELTER TO SURVIVAL. It has already been stated that the density of the shelter has a bearing upon the survival. This is best shown by the following records (Table XLVIII): Table XLVIII.—Relation of shelter of boll weevils to their survival. Place. Date installed. Weevils. Shelter. Survival. October 26 do 2,436 2,158 2,375 2,850 2,850 Average Per cent. Do October 28 November November Average Do Do Average RELATION OF CLIMATE TO SURVIVAL. Another important consideration in determining the causes for high or low survival is the climate. Some of the principal relation- ships are brought out in Table XLIX below: Table XLIX.—Relation of climate to survival of boll weevils in hibernation. Place and year. Tallulah, La., 1910-11. Dallas, Tex., 1907-8. Tallulah, La., 1909-10. Descript ion. 10 cages, variety of shelter, installed Oct. 15-Dec. 1. 9 cages, variety of shelter, Sept. 21- Nov. 18. 19 cages, great variety of shelter, Sept. 16- Dec. 14. Number of weevils. 8,439 12,087 21,835 Per cent of sur- vival. .9 Periods of emer- gence. Feb. 15-June Feb. 19-June 16. Feb. 15-June 27 . Rainfall and tempera- ture, Oct. 1-Mar. 15. Rain- fall. Inches. Abso- lute mini- mum. 'F. Total degrees below 32. °F. Please note that these images are
Size: 1410px × 1771px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectentomology
