A GLASS-VIAL TECHNIQUE FOR MONITORING TOLERANCE OF BEMISIA-ARGENTIFOLII (HOMOPTERA, ALEYRODIDAE) TO SELECTED INSECTICIDES IN ARIZONA

A glass-vial bioassay technique was used to assess the toxicity of bif enthrin, endosulfan, fenpropathrin, and fenpropathrin+acephate (1:1) t o adult Bemisia argentifolii Bellows & Perring. Initial surveys of B. argentifolii susceptibility to the test insecticides established a bas is for monitoring possible changes in population sensitivity to these products. Data on tolerance of B. argentifolii adult populations were obtained in 1992 (20 populations) and 1993 (22 populations) with treat ed glass vials. Surveys on populations from different host crops (cott on, cole crops, and melons) were done in different geographical areas in Arizona. Probit analysis of the results indicated that the LC(50)s from many of the test sites were significantly different, exhibiting v arious levels of tolerance to the insecticides tested. Host plants, cr op phenology, and the geographical region seemed to affect responses o f B. argentifolii populations.