Baseline susceptibility to chlorantraniliprole of Brazilian populations of Plutella xylostella
- 作者：Jefferson E. da Silva ; Herbert A.A. de Siqueira ; siqueira@depa.ufrpe.br ; Tadeu B.M. Silva ; Mateus R. de Campos ; Reginaldo Barros
- 关键词：Geographic variation ; Anthranilic diamides ; Diamondback moth ; Resistance monitoring ; Discriminating concentration
- 刊名：Crop Protection
- 出版年：2012
- 期刊代码：28_02612194
- 类别：abs
- 出版时间：May, 2012
- 卷：35
- 期：Complete
- 页码：97-101
- 文件大小：251 K
摘要
Chlorantraniliprole, a new anthranilic diamide, is an insecticide that has recently been registered in Brazil to control several lepidopterans, including the diamondback moth, Plutella xylostella (L.). Chemical control of this pest has been particularly difficult because of its evolution of resistance to previous insecticide classes. To deploy a chlorantraniliprole resistance-monitoring program, the susceptibility of P.聽xylostella populations from different regions of Brazil was assessed using concentration-mortality bioassays before the commercial release of chlorantraniliprole. Mortality data were subjected to Probit analysis to estimate lethal parameters. Dosing by immersion or by spraying in a Potter tower were both suitable but topical application was not. All of the P.聽xylostella populations were highly susceptible to chlorantraniliprole (LC50 0.015-0.056聽mg a.i./l of water) with those from the Northeast being the most tolerant. LC99 values were also low (0.065-0.281聽mg a.i./l). The susceptibility variation among the populations was notably low, with the highest tolerance ratio being 3.8 fold, indicating a low variability of response among the Brazilian populations to this insecticide. A discriminating concentration of 0.3聽mg a.i./l was obtained from the baseline data and proved to be effective for evaluating other populations, causing 100%mortality. The baseline data reflect the natural variation of these P.聽xylostella populations to chlorantraniliprole, rather than variations caused by previous exposure.