Efficacies of fifteen insecticides against <i>Spodoptera litura</i> (Fabricius) and <i>Spodoptera exigua</i> (Hübner) in Nara Prefecture

The efficacies of 15 insecticides at commercial concentrations were evaluated against Spodoptera litura (Fabricius) and Spodoptera exigua (Hübner) populations collected from production fields in Nara Prefecture, Japan during 2023–2025. For S. litura, spinetoram, lepimectin, chlorfenapyr, metaflumizone, indoxacarb, fluxametamide, broflanilide, and pyridalyl showed high efficacy 2–3 days after treatment. Methoxyfenozide was effective 5–8 days after treatment. For S. exigua, spinosad, spinetoram, chlorfenapyr, fluxametamide and broflanilide showed high efficacy 3 days after treatment, whereas methoxyfenozide was effective 5–8 days after treatment. In conclusion, several insecticides were found to have low efficacy against S. litura and S. exigua, but spinetoram, chlorfenapyr, methoxyfenozide, fluxametamide, and broflanilide were effective.