Transgenerational effect of Cordyceps fumosorosea (Wize) on demographic parameters and detoxifying enzymes of Spodoptera frugiperda (Smith).

Spodoptera frugiperda is a notorious pest that has been recorded attacking over 353 crop species worldwide. Excessive insecticide exposure can lead to resistance and has adverse impacts on the environment and beneficial organisms. Long-lasting pest control methods like entomopathogenic fungi may be used to prevent the negative impact of synthetic insecticides. In the current research, effectiveness of Cordyceps fumosorosea was analysed by applying a sub-lethal dose (LC₁₅ = 2.09 × 10⁶ spores mL^-1) and a lethal dose (LC₅₀ = 2.17 × 10⁷ spores mL^-1) on filial (F₀) and first filial (F₁) generations of S. frugiperda to estimate both lethal and sub-lethal effects. The LC₁₅ was used to keep a significant proportion of larvae alive to permit determination of sublethal effects on S. frugiperda. After treatment with the LC₁₅ and LC₅₀, S. frugiperda progeny displayed shorter larval duration, lower fecundity, and shorter adult female and male longevities relative to untreated controls. Likewise, the adult pre-oviposition period, total pre-oviposition period, oviposition days (O_d), net reproductive rates (Ro), and mean generation times (T) were reduced in fungal-infected groups. Furthermore, activities of key detoxifying enzymes, i.e. acetylcholinesterase (AChE), glutathione S-transferases (GST), and esterases (EST), were also evaluated. Substantial differences of AChE, GST, and EST (24.3, 18.34, and 10.09 µmol/min/mg protein), respectively, were observed at the LC₅₀ in contrast to the LC₁₅ and controls. The current study showed pathogenicity of C. fumosorosea, which negatively affected insect development and changed the activities of detoxifying enzymes, thereby increasing the effectiveness and eco-friendly management of S. frugiperda.