Volume : 3, Issue : 5, May - 2014
Understanding the Organophosphate resistance mechanisms to acetylcholine esterase in tobacco whitefly, (Bemisiatabaci)
Ramakrishna S, Nageshbabu R
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The tobacco whitefly B–biotype BemisiatabaciGennadius (Hemiptera: Aleyrodidae) is a worldwide pest of many crops. In India, Dichlorovas has been used to control this insect for many years and is still being used despite the fact that some resistance has been reported. To combat resistance and maintain good control efficiency of Dichlorovas, it is essential to understand resistance mechanisms. A Dichlorovas resistant tobacco whitefly strain (TB2) and a susceptible strain (TB1) were derived from a field collected population inIndia, and the resistance mechanisms were investigated. More than 30–fold resistance was achieved after selected by Dichlorovas for 13 generations in the laboratory. However, the resistance dropped significantly to about 18–fold in only 4 generations without selection pressure. Biochemical assays indicated that increased esterase activity was responsible for this resistance, while Acetylcholine esterase, Glutathione S–Transferase, and Microsomal–O–Demethylase played little or no role. F392W mutations in ace1 were prevalent in TB1 and TB2 strains and 6 field–collected populations of both B and Q–biotype from locations that cover a wide geographical area of India. These findings provide important information about tobacco whitefly Dichlorovas resistance mechanisms and guidance to combat resistance and optimize use patterns of Dichlorovas and other organophosphate and carbamate insecticides
Understanding the Organophosphate resistance mechanisms to acetylcholine esterase in tobacco whitefly, (Bemisiatabaci) Ramakrishna S, NageshBabu R Global Journal For Research Analysis, Vol:3, Issue:5 May 2014