Behavioral and Transcriptomic Analyses in the Indoxacarb Response of a Non-Target Damselfly Species.

Simple Summary: Ischnura senegalensis, a beneficial insect predator in the paddy fields, is perilously confronted with the survival challenges posed by insecticide application. In this study, we delved into the toxicity of indoxacarb on the larvae of I. senegalensis. Through behavioral experiments and transcriptome analyses, we uncovered that indoxacarb caused abnormal body movements and locomotory impairments, thereby posing a threat to larval survival. Notably, genes related to muscle function were significantly impacted. While lower concentrations of indoxacarb may be mitigated by the cytochrome P450 gene, higher concentrations significantly diminished the larvae's sensory abilities and hampered toxicity degradation. Our findings highlight the importance of meticulously considering the impact of insecticides on non-target predatory insects before their widespread application. Ischnura senegalensis, which widely spreads in paddy fields, has the potential to be used as a natural predator of insect pests. However, the application of insecticides in the field could pose a threat to the survival of I. senegalensis. Among these pesticides, indoxacarb, an oxadiazine insecticide, is renowned for its broad-spectrum efficacy against numerous insect pests. In this study, we examined the toxicity of indoxacarb towards the larvae of I. senegalensis. Behavioral experiments and transcriptome analyses were conducted under indoxacarb treatments. Results revealed that indoxacarb induced abnormal body gestures and significant locomotory impairments, which could ultimately reduce the survival rate of the larvae in their natural habitat. Moreover, transcriptome analyses indicated that genes related to muscle function were significantly affected. Interestingly, at lower concentrations of indoxacarb (0.004 mg/L), the larvae seem to detoxify the indoxacarb with the aid of the cytochrome P450 gene. However, under higher concentrations (0.4 mg/L), the sensory abilities of the larvae were significantly diminished, and they were unable to degrade the toxicity of indoxacarb. Our study underscores the importance of carefully evaluating the impact of insecticides on non-target predatory insects before their widespread application. [ABSTRACT FROM AUTHOR]