4 BULLETIN 564, U. S. DEPARTMENT OF AGRICULTURE. 



forms reaching the ground in the different plats. As one of the 

 larger field tests of the bag-and-hoop method was also located on this 

 same plantation, this intensive study was termed " Eureka Experi- 

 ment No. 2." 



■description of plats. 



For conducting this study a small block of cotton was selected in 

 the center of the cut. This cotton was a part of the general planting 

 of the cut and was farmed exactly the same as the surrounding cotton 

 throughout the season. The experimental area considered was 32 

 rows in width and 150 feet long. This was divided into eight plats of 

 four rows each. The two outside plats were left untreated as checks, 

 while plat 1 was shaken with the bag-and-hoop six times a week; 

 plat 2, five times; plat 3, four times; plat 4, three times; plat 5, twice; 

 and plat 6 once a week during the experimental period. These pickings 

 were distributed through the week as well as possible. In addition 

 to picking these plats a strip 30 feet in length beyond the end of each 

 plat was gone over each time that the adjoining plat was picked. 

 This was done simply to provide a buffer system which would protect 

 the plats from an immigration of weevils from unpicked cotton. 



The cotton variety used in these plats was the Simpkin's Ideal, and 

 a good stand prevailed at the beginning of the experiment. 



METHOD OF OPERATION. 



The method of collection used in these plats was the ordinary 

 system of bag-and-hoop shaking, the plants being shaken into a sack 

 held open by a hoop sewn in the mouth. 



Negro laborers were used for the work, but they were under the 

 constant supervision of an entomologist, and care was taken to 

 make the work very thorough. Unnecessary injury to the plants 

 was avoided as much as possible. At the beginning of the season 

 bags about 20 inches in diameter were used for the small plants, but 

 these were later replaced by considerably larger ones which allowed 

 a reasonably thorough treatment as long as the pickings were 

 continued. 



The pickings were started on June 12. The plats had been watched 

 carefully for some weeks before that time in order to start the picking 

 as soon as the weevils became sufficiently abundant to make the 

 records of any value. The initial spring infestation in this particular 

 cut of cotton was rather light, and it was not until about this date that 

 any weevils could be located in the plats. Following this first picking 

 the schedule mentioned was continued for nine weeks, thus making 

 the total pickings of the different plats range from 9 in plat 6 to 54 

 in plat 1. 



