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The role of B‐type esterases in conferring insecticide resistance in the tobacco whitefly, Bemisia tabaci (Genn)
Author(s) -
Byrne Frank J,
Gorman Kevin J,
Cahill Matthew,
Denholm Ian,
Devonshire Alan L
Publication year - 2000
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/1526-4998(200010)56:10<867::aid-ps218>3.0.co;2-p
Subject(s) - whitefly , biology , permethrin , esterase , population , pest analysis , bioassay , pyrethroid , toxicology , enzyme , botany , pesticide , genetics , biochemistry , agronomy , demography , sociology
Separation of non‐specific esterases on electrophoretic gels has played a key role in distinguishing between races or biotypes of the tobacco whitefly, Bemisia tabaci . One intensively staining esterase in particular (termed E 0.14 ) has assumed significance as a diagnostic of B‐type whiteflies (aka Bemisia argentifolii ), despite any knowledge of its biological function. In this study, a whitefly strain (B‐Null) homozygous for a null allele at the E 0.14 locus that had been isolated from a B‐type population was used to demonstrate a significant role for E 0.14 in resistance of B‐type populations to pyrethroids but not to organophosphates (OPs). Bioassays with pyrethroids, following pre‐treatment with sub‐lethal doses of the OP profenofos (to inhibit esterase activity), coupled with metabolism studies with radiolabelled permethrin, supported the conclusion that pyrethroid resistance in a range of B‐type strains expressing E 0.14 was primarily due to increased ester hydrolysis. In the same strains, OP resistance appeared to be predominantly conferred by a modification to the target‐site enzyme acetylcholinesterase. © 2000 Society of Chemical Industry