Age-Stage, Two-Sex Life Table Study of the Effects of Sub-Lethal Concentrations of Novaluron on Earias vittella (Lepidoptera: Noctuidae)

Abstract

Earias vittella (F) is an important insect pest of cotton (Gossypium hirsutum) and okra (Abelmoschus esculentus) in Pakistan. The current study was carried out to explore the effects of sub-lethal concentrations of novaluron on the life table parameters of the pest. Bioassays were performed to assess the sub-lethal concentrations (LC20 and LC50) of the novaluron and its effects on the demographic parameters of the E. vittella. Age-stage, two-sex life table theory was applied to interpret the data for population parameters of E. vitella. In the current study, the LC20 and LC50 were calculated as 2.224 ppm and 9.837 ppm, respectively. The results showed that in novaluron treated samples rates of all biological parameters decreased whereas the larval, pupal period and mean generation time were increased. The intrinsic rate of increase remained high in control as 0.166 d-1 in comparison with LC50 as 0.128 d-1. The net reproductive rate ranged from 94.542 offsprings per individual (control) to 61.228 offsprings per individual (LC50). Fecundity was dropped in insects treated with sub-lethal concentrations from 330.9 eggs per female (control) to 238.11 eggs per female (LC50). This study revealed that the sub-lethal concentrations of novaluron significantly decreased the biological rate of E. vitella under laboratory conditions and suggests that such doses should be practiced in the fields for proper integrated pest management strategies. © 2022 Friends Science Publishers