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218 



rehibemated in A in. of woods trash which was dry (no moisture added) , were 

 moistened with the equivalent of normal rainfall (14.8 in.), or were wetted 

 with 3-times normal rainfall. Numbers of surviving weevils that had remained 

 in the trash where they were placed were significantly higher in trash 

 treated with normal rainfall than in trash otherwise treated. However, 30X 

 of the surviving weevils moved from their original locations, and signifi- 

 cantly greater numbers moved to the dry trash or to trash treated with normal 

 rainfall. Significantly greater survival occurred at the 1-in. depth in trash 

 treated with normal rainfall than at any depth in the other 2 treatments. 

 The overall recovery of weevils in this experiment was 48%. 



422. House, V. S.; Abies, J. R. ; Jones, S. L. ; and Bull, D. L. 1978. 



Diflubenzuron for control of the boll weevil in unisolated cotton 



fields. J. Econ. Entomol. 71: 797-800. 

 In a 1976 test in unisolated cotton fields, different rates 35, 70, and 140 

 g Al/hs) of the insect growth regulator diflubenzuron, N-[ [ (4-chlorophenyl) 

 amino]carbonyl]-2, 6-difluorobenzamide, were applied aerially over a 6-wk 

 period to suppress populations of Anthonomus grandis Boheman. There was a 

 pronounced dosage rate response to the chemical in that the percentage emer- 

 gence of adult weevils from cotton squares collected from treated fields 

 averaged 37.7, 22.2, and 15.8% at the lowest, median, and highest rate, re- 

 spectively. Adult emergence from squares collected in untreated control 

 plots averaged 70% during the same period. The reduction in weevil emergence 

 was most pronounced in the F, generation and somewhat less in the F2 and F^ 

 generations. A similar emergence pattern was observed in 1977 but due to a 

 delay in the initial treatment the effect lagged by 1 generation. In both 

 years, there was an apparent rebound by pest populations during the latter 

 part of the season as Indicated by increased emergence from the field 

 collected squares. This result was attributed to movement of untreated 



