MONITORING TOLERANCE TO INSECTICIDES IN BOLL-WEEVIL POPULATIONS (COLEOPTERA, CURCULIONIDAE) FROM TEXAS, ARKANSAS, OKLAHOMA, MISSISSIPPI, AND MEXICO

A glass vial technique was developed to estimate the toxicity of organ ophosphorus, carbamate, cyclodiene, and pyrethroid insecticides to the boil weevil, Anthonomus grandis grandis Boheman, and to monitor field populations for tolerance to such insecticides. In tests in which res ponses of the USDA Ebony strain boil weevils were compared with those collected in the field in the Brazos Valley, TX, in 1988, tolerance to organophosphorus, pyrethroid, and carbamate insecticides was demonstr ated. The usefulness of the glass vial technique for monitoring tolera nce was confirmed in 1991 and 1992 by field data from Texas, Arkansas, Mississippi, Oklahoma, and Sonora, Mexico. These tests indicated tole rance to organophosphorus and pyrethroid insecticides in several boil weevil populations. Tolerance monitoring may be a useful technique in the implementation of boil weevil eradication programs.