45 



summer. The late season suppression of prehibernating boll weevils is 

 probably the only insecticidal control method for boll weevils which does 

 not frequently provoke economically damaging outbreaks of nontarget pests 

 such as Heliothis . However, variables such as ecological stability, in- 

 secticide type, and timing of treatment will determine the degree of im- 

 pact the control treatments have on these pests and thus should be con- 

 sidered before this control method is used as a wide scale management tactic. 



77. ; Rummel, D. R. ; and Adkisson, P. L. 1972. Spread of the boll weevil 

 into the High Plains of Texas. Environ. Entomol. 1: 136-140. 



In recent years Anthonomus grandis Boheman has invaded the High Plains, where 

 it currently presents a potential threat to cotton in most of the area. A 

 large-scale insecticidal control program was conducted during each of the years 

 1964-70 to control the insect. The programs were effective in preventing 

 economic boll weevil damage to cotton in the High Plains. Despite these 

 control efforts, low numbers of the insect advanced many miles west into 

 previously uninfested counties of the High Plains during 1967-69. Distribution 

 of the insect during 1964-70 in the High Plains and adjacent areas of West 

 Texas is presented. 



78. ; Wade, L. J.; and Bruce, D. L. 1973. Boll weevils fail to develop 

 resistance to malathion after several years of heavy exposure in the 

 Texas High Plains. J. Econ. Entomol. 66: 791-792. 



The dosage-mortality data obtained in 1968 and 1971 with weevils of the 

 control zone and check strains showed similar trends, that is, there was 

 little difference between strains when compared at either the LDcq or LDqr, 

 levels both years. It seemed unusual that the LD^q and LDg^ values deter- 

 mined for both strains were smaller in 1971 than in 1968, but the important 

 point is that there was no evidence that the High Plains strain had developed 



