Sublethal impacts of Buprofezin and Pyriproxyfen on cotton mealybug Phenacoccus solenopsis through transgenerational hormesis

Abstract

Abstract Insect pests are exposed to repeated applications of pesticides to effectively manage the pest species. This induces insecticide resistance and resurgence of target insect pest with an accelerated growth rate of the targeted individual. The present experiment was put into execution to examine transgenerational hormesis against different biological parameters of Phenacoccus solenopsis when exposed to sublethal concentrations of Pyriproxyfen (Pyriproxyfen® 10 EC) and Buprofezin (Buprofezin® 25 WP). Insects exhibited concentration-dependent mortality diminishing in succeeding generations. P. solenopsis receiving the sublethal concentration of LC10 (0.03%) of Pyriproxyfen® exhibited hormesis in natality in generation (G)-4 (1282.4 nymphs/20 females) and G-5 (1296.2 nymphs/20 females). The adult female exposed to LC10 (0.02%) of Buprofezin® also expressed hormesis in natality in G-4 (1261.5 nymphs/20 females) and G-5 (1282.8 nymphs/20 females). Hormesis in female longevity was also found when treated with a sublethal concentration of LC10 for Pyriproxyfen® (0.03%) in generation four (46.41 days) and five (46.35 days). Similarly, adults in G-4 and G-5 at a sublethal concentration of LC10 (0.02%) for Buprofezin® induced hormesis in G-4 (45.53 days) and G-5 (46.69days), whereas in G-4 (4.79 days) and G-5 (4.92days) at stimulatory concentrations of LC10 (0.03%) of pyriproxyfen®. The whole research ended up with a conclusion that continuous administration of sublethal concentrations can induce stimulations in different biological traits demonstrating the surprising biological capacity of insects to cope with stressors and contemplation of this aspect is necessary when integrating the pest management programs.