Demographic Analysis of Progeny Fitness and Timing of Resurgence of Laodelphax Striatellus After Insecticides Exposure

Abstract

The resurgence of Laodelphax striatellus (Fallen) (Hemiptera: Delphacidae) associated with repeated applications of certain insecticides has been observed over the past several years. To comprehensively assess the effect an insecticide has on the offspring fitness and resurgence of a pest, accurately determining the survival, development, and fecundity of the population being investigated is a necessity. Because life tables include these, and other parameters of a population, they are a crucial tool for accomplishing this goal. In the present study, we evaluated the effects of three insecticides, cyantraniliprole, imidacloprid, and dinotefuran on progeny fitness and resurgence risk of L. striatellus by using the age-stage, two-sex life table. Experimental results show that the net reproductive rate (R-0) and fecundity (F) of the F1 progeny of L. striatellus treated with cyantraniliprole (R-0 = 131.68 and F=381.03) and imidacloprid (R-0 = 115.74 and F = 417.20) were significantly higher than that of the L. striatellus treated with dinotefuran (R-0 = 64.11 and F= 249.0) and untreated population (R-0 = 77.97 and F = 246.54). No significant difference was found in the intrinsic rate of increase (r) and finite rate of increase (lambda) among treatments, except for the difference between cyantraniliprole and dinotefuran. Population projection showed that the offspring population of L. striatellus would increase faster after being treated with cyantraniliprole than the control population. These findings demonstrate that applications of cyantraniliprole to control L. striatellus may increase the fitness of their progeny, leading to a likely resurgence of this pest.