Biology of Helicoverpa armigera (Hubner) Hardwick on Okra in the Laboratory Condition Chaudhary M. G.*, Chaudhary H. K., Chaudhary R. J. Department of Entomology, C. P. College of Agriculture Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar *email: chaudharymavji@gmail.com
Online published on 2 January, 2017. Abstract Helicoverpa armigera was considered as a minor pest of okra but now a days it becomes a major pest of okra especially in North Gujarat condition. The female moths laid eggs singly usually on okra fruits, sometimes on newly emerged okra fruits, flower, buds and leaves. The length and breadth of eggs were 0.45 ± 0.04 and 0.47 ± 0.04 mm, respectively. The incubation period was 3.60 ± 0.84 days with a hatching percentage of 87.80. The H. armigera passed through six instars. The length and width of first, second, third, fourth, fifth and sixth instar larvae were 1.69 ± 0.18 and 0.72 ± 0.01, 4.89 ± 0.21 and 0.57 ± 0.02, 9.32 ± 0.42 and 1.15 ± 0.03, 17.52 ± 0.70 and 2.25 ± 0.12, 27.81 ± 0.91 and 3.42 ± 0.41 and 36.17 ± 1.62 and 34.47 ± 0.35 mm, respectively. The length and width of pre-pupa varied from25.98 ± 0.63 and 4.78 ± 0.21 mm and the pupal length and width were 19.6 ± 1.34 and 5.82 ± 0.49 mm, respectively. The average developmental period of first instar, second instar, third instar, fourth instar, fifth instar and sixth instar of H. armigera were 2.58 ± 0.53, 3.16 ± 0.70, 3.88 ± 0.77, 4.12 ± 1.06, 5.42 ± 1.23 and 5.95 ± 1.41 days, respectively. The total larval period varied from18 to 27 days with an average of 22.3 ± 2.82 days. The average developmental period of pre-pupal stage was 2.26 ± 0.35 days and pupal period was of 10.93± 2.82 days. The average length and width of adult male varied from 17.42 ± 0.28 and 35.18 ± 1.34 mm, respectively while, in case of female it varied from 19.94 ± 0.56 and 39.73 ± 1.48 mm, respectively. The average longevity of male and female were 6.53 ± 0.70 and 8.62 ± 2.12 days, respectively and total life period of male and female were 47.86 ± 4.24 and 50.06 ± days, respectively. The average pre-oviposition, oviposition and post-oviposition period were 2.86 ± 0.70, ± 1.41 and 1.40 ± 0.70 days, respectively. The fecundity of female recorded to be 541.46 ± 43.84 eggs. Sex ratio of male: female was 1: 1.29. Top Keywords Biology, Helicoverpa armigera, okra, fecundity, longevity. Top |