Efficacy of lufenuron, a chitin synthesis inhibitor on the mortality of Spodoptera litura (Fabricius) under laboratory conditions

Effectiveness of Heron 5 EC (Lufenuron) was evaluated against 3rd instar larvae of Spodoptera litura (Fab.) under laboratory conditions for time-oriented mortality with three different concentrations through different treatment methods. The larvae were treated with three different concentrations like 25, 50 and 75 ppm of lufenuron through three different treatment methods viz. direct or topical, indirect and combined. The highest mortality (about 100%) was observed from 75 ppm which was followed by 50 and 25 ppm respectively. The larval mortality was recorded at 6 hours after treatment (HAT) and 1-5 days after treatment (DAT) application. Considering the efficacy as well as mortality-duration among three treatment application methods, the combined method proved the best (100% mortality at 3 DAT in all concentrations of lufenuron) which was closely followed by indirect (100% mortality at 4 DAT in all concentrations of lufenuron) and topical method (83.30 to 100% mortality at 5 DAT in different concentrations of lufenuron). From this study, it can be concluded that Heron (Lufenuron) is very much effective against S. litura while stomach action is more effective compared to the direct or topical action.