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Subject: Entomology × Author: Bhatt, Priyanka × End date: 2017 × Start date: 2010 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Bioefficacy of botanicals and insecticides against polyphagous insects and phagostimulant activity of medicinal plants to Bombyx mori Linn.
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2013-07) Bhatt, Priyanka; Srivastava, R.P.
    A detailed investigation was undertaken to evaluate the effect of medicinal plant extracts and oils on Bombyx mori Linn. and Spodoptera litura Fab. and bioefficacy and growth regulatory activities of some medicinal plant oils and insecticides against S.litura and Spilosoma obliqua (Walker). All the experiments were conducted in Mulberry Sericulture Laboratory/Bioactive Plant Natural Products (BPNP) Lab. of the Department of entomology. The culture of the test species was maintained on fresh leaves of mulberry Morus alba (Linn.) and castor, Ricinus communis (Linn.).An experiment was conducted to find out phagoactivity of methanol powder (concentrations-0.5 & 1%) of five medicinal plant species viz., Ageratum conyzoides, Anethum graveolens, Lantana camara, Melia azedarach and Pteris excelsa to 24d old worms of B. mori. Methanol powder of M.azedarach (1%) reflected feeding stimulating activity (Mean leaf area consumed was 8.25cm2) over control (7.80cm2). High feeding deterrent property was exhibited by A.conyzoides flower head at 0.5 and 1% conc. (92.59 & 97.46%, respectively) folllowed by L.camara leaves at 0.5% (77.27%). In another experiment eleven plant oils viz., Asparagus racemosus, Celastrus paniculatus, Juglans regia, Myristica fragrans, Psoralea corylifolia,Cinnamomum tamala, Elettaria cardomum, Hedychium spicatum, Lagenaria vulgaris, Santalum album and Trigonella foenum-graecum (conc. 1 and 2%) were tested for their phagostimulant activity to 22 and 23d old worms of B.mori. Among all the treatments, only A.racemosus, J.regia and P.corylifolia at 1& 2% enhanced feeding in 22d old worms of B.mori; and S.album and T.foenum-graecum at 1& 2% and L.vulgaris at 2% were preferred by 23d old worms of B.mori.An experiment was conducted to evaluate the effect of four medicinal plant species viz., Anthocephalus chinensis, Bixa orellanaa, Calotropis procera and Madhuca indica on feeding behaviour of 8d old larvae of S. litura.Highest feeding inhibition was exerted by M.indica (51.34%). Further, the growth and developmental study revealed a significant reduction in wt. gain four days after feeding (DAF) in all the treatments, the highest being in M.indica (0.002 and 0.011g) in comparison to control (0.24 and 0.31g) against 4 and 7d old larvae of S.litura respectively. Significantly high larval mortality was observed with B.orellana (100 and 90%) and M.indica (100 and 63.33%) against 4 and 7d old larvae.Pupation per cent and adult emergence was significantly lower in B.orellana and M.indica.A comparative effect of methanol powder of nine plant species (at 5 and 10mg/ml) viz., Andrographis paniculata, Anethum graveolens, Azadirachta indica, Cassia fistula, Cuscuta reflexa, Dendropthoe falcata, Lantana camara, Melia azedarach and Vitex negundo wss evaluated against 2 and 6d old larvae of S. litura.Maximum growth reduction was observed in D.falcata leaves (98.58%) and L.camara fruit (93.58%) at 5mg/ml and C.reflexa stem (98.58%), C.fistula seeds and L.camara leaves (both 92.86%) at 10mg/ml against 2d old larvae and L.camara fruit at 5 and 10mg/ml (99.43 and 99.93%) against 6d old larvae.A.indica and L.camara fruit at 10mg/ml were more toxic to 2d old larvae giving 83.33 and 100% mortality, respectively while only L.camara fruit proved toxic against 6d old larvae of S.litura. In another experiment three plant oils viz., Jatropha curcas, Syzygium aromaticum and Veteveria zizanioides were tested at 2.5, 2.0,1.5,1.0 & 0.5% for their contact toxicity against 6d old larvae of S. litura. The order of toxicity at 12h, LC50 level was V.zizanioides (0.85%) > J.curcas (1.37%) > S. aromaticum (1.38%).An experiment was conducted to study the effect of camphor oil, Cinnamomum camphora at conc. of 0.5, 1.0, 1.5, 2.0 and 2.5μl/larva on feeding, growth and development of 8d old larvae of S.litura by topical application bioassay method.Significant reduction in weight gain/larva and larval mortality one day after exposure(DAE) was maximum at 2.5, 2.0 and 1.5μl dose.No adult emergence was reported at the aforesaid doses.An experiment was conducted to examine the contact toxicity of three insecticides viz alphamethrin (0.05, 0.009, 0.007,0.005 &0.003%), chlorpyrifos (0.1, 0.05, 0.005, 0.003 &0.001%) and emamectin benzoate (0.05,0.005,0.002, 0.005 & 0.0002%) against 13d old larvae of S.obliqua .The order of toxicity at 48 h LC50 level was: emamectin benzoate (0.002%)>chlorpyrifos (0.009%)>alphamethrin (0.013%).In another experiment, the effects of clove oil, Syzygium aromaticum and camphor oil, C.camphora (each at doses of 0.5, 1.0, 1.5, 2.0 and 2.5μl/larva) were evaluated on growth and development parameters of 13 and 15d old larvae of S.obliqua, respectively.Weight gain was significantly reduced in clove oil by 0.340,0.357 and 0.372 g in comparison of control (0.477g) at 2.5, 1.5 and 1.0μl/larva, respectively. Larval mortality was highest at 2.5μl/larva and further pupation per cent and adult emergence was lowest. Camphor oil at this dose viz 2.5μl/larva lowered weight gain by 0.073g in comparison of control (0.289g).Larval mortality was 66.6% with low pupation per cent and no adult emergence.