The data show that the rate at which the weevil inTestation increases 

 through one generation depends upon the magnitude of the parental popula- 

 tion in relation to the total food available at any given time. If the 

 parental population is relatively small, either naturally or because of 

 effective control measures, the rate of population increase will be high 

 in the absence of imposed artificial restrictions, while the rate of in- 

 crease per generation from a large parental population may be low. To 

 illustrate, the infestation in field l5 (table 7) is compared with that 

 of field 3 (table U). The infestation in field l5, which had a relatively 

 large population on July 31 (26.8 percent punctured squares) was 91.5 

 percent or 3.U times the previous figure on August 28. In field 3, which 

 had a smaller population (5.5 percent punctured squares) on August 2, the 

 infestation on August 28 was 5l.l percent or 9.2 times the previous figure, 

 in the absence of control measures during the same period. 



When comparisons are made of the infestation figures in tables h to 

 7, the numbers of squares and plants per acre must be considered in 

 estimating the existing or potential future population. For example, a 

 0. ■6-percent infestation on July 21; in field 3 (table k) with 166,910 

 squares per acre, represents 985 punctured squares per acre, whereas a 

 comparable percentage of infestation, 0.6 percent on July 31 in field 5 

 (table h) with 76,267 squares per acre, represents I|.19, or less than one- 

 half as many punctured squares per acre. This indicates a considerably 

 smaller adult population present at that time in field S, as well as a 

 smaller potential population in the succeeding generation. Hence, a 

 relatively low percent of infestation in an unprotected field containing 

 large numbers of squares' can rapidly increase to damaging proportions 

 (table 5). However, even four or five late-season insecticide treatments 

 at only partially effective dosages and intervals can delay population 

 development (table h) • 



Woods trash examinations, consisting of k$ two -square -yard samples 

 taken from hibernation sites in the Wallace treatment area in Marlboro 

 County in the spring of I96I, showed an average of 1,291 weevils per acre 

 in hibernation. Similar woods trash examinations, consisting of 90 two- 

 square-yard samples, were made in Florence, Darlington, and Marlboro 

 counties. South Carolina, and Scotland County, North Carolina. An average 

 of 1,129 weevils per acre in the four-county area indicated that the pop- 

 ulations in the two areas were comparable. Woods trash examinations were 

 made in the same areas in the fall of I96I. These indicated an average 

 of 5^380 weevils per acre in hibernation in the treatment area compared 

 with an average of 13,632 in the four-county area. This is a 60. 5-percent 

 reduction in the number of hibernating weevils in the area receiving the 

 community-control treatments, as compared with the nearby four-county area. 



Woods trash examinations in the spring of 1962 in the same areas in- 

 dicated an average of I,l8l4 weevils per acre in hibernation in the treat- 

 ment area and 3j65l4. in the four-county area. The 67.6 percent reduction 

 of weevils found in the treatment area is comparable with that found in 

 the fall of 1961. 



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