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

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, along 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 G-4 (46.41 days) and G-5(46.35 days). Similarly, adults in G-4 and G-5 at a sublethal concentration of LC₁₀ (0.02%) for Buprofezin® induced hormesis 45.53 days and 46.69 days, respectively, whereas in G-4 (4.79 days) and G-5 (4.92 days) at stimulatory concentrations of LC₁₀ (0.03%) for pyriproxyfen®. The research findings indicate that the consistent application of sublethal concentrations can elicit stimulatory effects on various biological traits. This highlights insects’ remarkable ability to adapt to stressors. It is imperative to consider this aspect when incorporating pest management programs.