Invasive Species Compendium

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Abstract

Food consumption and utilization pattern of fall armyworm (Spodoptera frugiperda j. e. Smith) in different genotypes of cotton.

Abstract

Fall army worm (FAW), Spodoptera frugiperda (J. E. Smith), a native species of tropical and subtropical regions of the America invaded into India quite recently. A study was conducted to know the food consumption and utilization pattern of fall armyworm (FAW) in cotton under laboratory conditions. Highest consumption indices (CI-1.18, GR- 0.23 mg/day, ECI-17.50%, ECD-42.81% and AD-51.32%) were indicated by larvae when fed with leaves of a non-Bt cotton genotype DHH-11. S. frugiperda Bt revealed the lowest consumption and utilization indices when fed on leaves of cotton hybrid Bindas BG II (CI-0.21, GR- 0.07 mg/day, ECI-7.32%, ECD-18.44% and AD-22.44%). When larvae were fed with squares of non-Bt cotton genotype DHH-11 showed highest indices (CI -0.87, GR- 0.27 mg/day, ECI-38.51%, ECD-53.37% and AD-64.55%) while lowest indices recorded on Bindas BG II Bt (CI -0.30, GR- 0.09 mg/day, ECI-17.57%, ECD-22.53% and AD-31.52%). Similar effect was noticed when larvae fed with cotton bolls Non-Bt cotton genotype DHH-11 could lead to highest indices (CI - 0.87, GR-0.46 mg/day, ECI-38.80%, ECD-59.44% and AD-74.31%) whereas Bindas BG II Bt cotton genotype was not well accepted by the larvae and led to the lowest food intake, utilization and assimilation indices (CI-0.16, GR-0.10 mg/day, ECI-22.49%, ECD-28.41% and AD-40.22%). Among non-Bt genotypes Suvin indicated the lowest value for all the parameters. Among leaf, square and boll fed to the larvae the highest CI (1.18) was noticed for leaves and lowest (0.16) for boll. But highest GR (0.46 mg/day) was indicated when larvae were fed on the bolls followed by squares (0.27 mg/day). Hence, bolls and squares found to be more nutritious than leaves to larvae of S. frugiperda.