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Experiment Background
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Cotton leaf roller, Sylepta derogata (Fabricius) (Lepidoptera: Pyralidae), nowadays observed in cotton especially in non-Bt cotton. The pest occurs in India, Pakistan, Bangladesh, Burma, Australia, Africa, China, Japan and Sri Lanka. The pest is active from the month of September to November. The pest is a polyphagous insect that feeds on Malvaceous plants such as Gossypium hirsutum, Abelmoschus esculentus, Hibiscus rosasinensis, Urena lobata, Althaca rosea, Sida cordifolia, Malvastrum tricuspidatum (Mariselvi and Manimegalai, 2016). The caterpillars roll up the leaves in a funnel shape and feed on the margin by remaining inside. In case of heavy infestation, phyllophagous could alter the photosynthetic activity of the plant and completely defoliation (Kamaraj et al., 2008). Among the caterpillars of cotton, leaf roller inducing up to 20 to 60 per cent cotton yield loss (Silvie, 1993). The keeping lacuna in information available on the leaf roller activity, biology and management on cotton present investigations will be carried out with the following objectives: |