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Subject: Entomology × Author: Gurpreet Singh × Start date: 1968 × Type: Thesis × Thesis Type: M.Sc ×
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    Bioactivity of Azadirachta indica on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)
    (Punjab Agricultural University, Ludhiana, 2022) Gurpreet Singh; Chandi, Anureet Kaur
    formulations (commercial neem formulation, neem oil and NSKE) on Spodoptera frugiperda in the laboratory conditions. Various toxicity concentrations (LC30 and LC50) of the neem based formulations i.e. commercial neem formulation (0.000169 and 0.000288 per cent), neem oil (0.045 and 0.238 per cent) and 5 per cent neem seed kernel extract (0.695 and 1.348 per cent) were worked out after treating second instar larvae by employing standard leaf-disc dip method of bioassay. The commercial neem formulation (LC30 and LC50) significantly increased the larval duration (24.20 and 37.0 days as compared to 22.40 days in untreated), pupal duration (8.40 and 9.80 days as compared to 6.60 days in untreated) and decreased the pupal weight (0.142 and 0.138 g as compared to 0.204 g in untreated), pupal size (7.960 and 7.280 mm length as compared to 8.467 mm in untreated and 2.309 and 2.256 mm breadth as compared to 3.909 mm in untreated), adult emergence (62.0 per cent as compared to 92.0 per cent in untreated), adult longevity (4.80 days male as compared to 8.60 days in untreated and 5.0 days female as compared to 9.0 days in untreated), male adult size (12.023 mm length as compared to 14.081 mm in untreated) and female adult size (11.939 mm length as compared to 13.598 mm in untreated) in comparison to the other formulations i.e. neem oil and NSKE. The reproductive parameters were also highly impacted by commercial neem formulation. The decline in oviposition period (2.9 days as compared to 7.0 days in untreated), fecundity (141.0 as compared to 429.6 in untreated), egg size (1.718 mm3 as compared to 2.280 mm3 in untreated), reproductive effort (246.15 as compared to 979.20 in untreated), egg hatchability (64.94 per cent as compared to 92.82 per cent in untreated) and survival of larvae (37.64 per cent as compared to 82.39 per cent in untreated) was recorded. However, the maximum antifeedant activity was observed in case of NSKE (43.53 and 72.06 per cent) in comparison to commercial neem formulation (27.37 and 58.97 per cent) and neem oil (17.51 and 50.59 per cent). The Relative Consumption Index (RCI) was also high in case of NSKE (0.449 and 0.808) followed by commercial neem formulations (0.173 and 0.605) and neem oil (0.084 and 0.371). The elevated value of antifeedant activity and RCI indicates the higher level of feeding deterrent. Therefore, neem based formulations can be incorporated in S. frugiperda integrated management programme on maize as an important and viable component.