Sex-Related Larval Susceptibility of Diamondback Moth, Plutella xylostella （Lepidoptera：Plutellidae） to some Reduced-Risk Insecticides  

作　　者：Hongyi Wei Henry Yemisi Fadamiro 

机构地区：[1]College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China [2]Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA

出　　处：《Journal of Agricultural Science and Technology(A)》2013年第11期870-877,共8页农业科学与技术（A）

摘　　要：Five reduced-risk insecticides were compared for their toxicities to male and female third instar larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera：Plutellidae） obtained from a laboratory colony. Leaf-dip bioassays were used to assess larval mortality at different insecticides rates （ranging from 0.01 mg AI/L to 100 mg A1/L） and exposure times （24, 48 and 72 h after treatment）. Toxicity of the insecticides generally increased with rate and exposure time. At 72 h after treatment, median lethal concentrations （LCs0s） of methoxyfenozide, spinosad, novaluron, indoxacarb and Bacillus thuringiensis （Bt） against the male third instar larvae of P, xylostella were 0.0524, 0.1117, 0.9149, 1.1939 and 4.4983 mg AI/L, respectively, and were 0.1008, 0.2583, 1.0649, 0.2850 and 5.3053 mg AI/L against female third instar larvae, respectively. At 0.1% of the approximate recommended field rates, methoxyfenozide （60%-75%） and spinosad （53%-57%） were the most toxic, while Bt （30%-45% mortality） was the least toxic to male and female P. xylostella larvae. Spinosad was the fastest acting and the only insecticide that caused significant larval mortality （17%） at 24 h after exposure. Significant sexual differences were recorded in the susceptibility of P. xylostella larvae to two of the insecticides： spinosad and indoxacarb. Male larvae were two-fold more susceptible to spinosad but 10-fold more tolerant to indoxacarb than female larvae.

关 键 词：DBM Plutella xylostella INSECTICIDES toxicity susceptibility. 

分 类 号：S482.84[农业科学—农药学] S881.21[农业科学—植物保护]