Analysis of time- and concentration-mortality relationship of nitenpyram against different larval stages of Nilaparvata lugens (Hemiptera: Delphacidae).
Bioassay of nitenpyram was conducted on the planthopper Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) in the laboratory by using the rice-stem dipping method. The resulting data were analyzed using the complementary log-log time-concentration-mortality modeling technique, yielding the parameters for time and concentration effects of nitenpyram against N. lugens instars. The LC50 values to instars I and II estimated for 24, 48, and 72 h after treatment were 1.03, 0.27, and 0.11 mg/liter, respectively. These values were lower than those for instars III and IV and instars V at the same times. The estimates of LT50 for instars I and II were decreased from 69.06 to 16.22 h with the increasing concentration from 0.125 to 2 mg/liter; the same estimates for both instars III and IV and instars V at the concentrations of 1-2 mg/liter were close to each other, ranging from 33.11 to 44.16 h, much higher than the values of instars I and II at the same concentration. Based on the time-concentration-mortality relationships fitted and the virulence indices (LC50 and LT50) estimated, nitenpyram is a promising pesticide for N. lugens control.
State Key Laboratory for Biocontrol & Institute of Entomology, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China.
Jie
J
Zhang
Jie
J
Liu
Xiao-Wa
XW
Qin
Feng-Hui
FH
Yuan
Run-Jie
RJ
Zhang
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006430:Hemiptera / Q000187:drug effects*; D007300:Insect Control / Q000379:methods; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects*; D000073943:Neonicotinoids; D011725:Pyridines / Q000633:toxicity*; D014774:Virulence / Q000187:drug effects
D007306:Insecticides; D000073943:Neonicotinoids; D011725:Pyridines; C464843:nitenpyram