. Bulletin of the Department of Agriculture. Agriculture. 4 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. METHODS USED IN THE STUDY OF THE BIOLOGY OF THE BOLL WEEVIL UNDER FIELD CONDITIONS. Large 16-mesh galvanized-wire screen cages 3 by 3 by 4 feet high were used in conducting the field biological studies of the weevil. The cotton plants used in the breeding work were first examined carefully to make certain that no infested squares were present. The large cages were then placed over the plants and a male and a CAROLINA. Fig. 1.—^Map of the sea-island cotton area of the United States sh
. Bulletin of the Department of Agriculture. Agriculture. 4 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. METHODS USED IN THE STUDY OF THE BIOLOGY OF THE BOLL WEEVIL UNDER FIELD CONDITIONS. Large 16-mesh galvanized-wire screen cages 3 by 3 by 4 feet high were used in conducting the field biological studies of the weevil. The cotton plants used in the breeding work were first examined carefully to make certain that no infested squares were present. The large cages were then placed over the plants and a male and a CAROLINA. Fig. 1.—^Map of the sea-island cotton area of the United States showing distribution by counties. Each dot represents an average production of 500 bales. (From Orton, Bur. Plant Industry, U. S. D. A.) female boll weevil liberated in each cage. On the following day all squares found with egg punctures were recorded, each infested square bearing a light string tag showing the number of the weevil and the date of the egg puncture. After the squares were examined and tagged the cage and weevil were removed to a noninfested plant and the process repeated. Daily observations were made on the plants bearing the tagged squares and the date the infested square dropped off the plant was recorded on the tag. As soon as the infested squares dropped off the plants they were placed in a field hatchery. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Dept. of Agriculture. [Washington, D. C. ?] : The Department : Supt. of Docs. , Govt. Print. Off.
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