Study on biology and physical measurements of shoot borer, Leucinodes orbonalis (Guenee) on the potato, Solanum tuberosum (L.) during kharif and rabi season

Abstract

The present investigation on biology of shoot borer, Leucinodes orbonalis Guenee on potato during both the seasons (kharif 2016 and rabi 2016-17) revealed that the average pre-oviposition period was 1.40 ± 0.52 and 1.42 ± 0.28 days, oviposition period 2.57 ± 0.18 and 2.77 ± 0.20 days, fecundity 157.30 ± 9.71 and 79.80 ± 29.51 eggs, incubation period 3.95 ± 0.54 and4.74 ± 0.39 days, total larval period 14.96 ± 0.52 and 17.03 ± 0.76 days and pre-pupal period 1.45 ± 0.09 and 1.63 ± 0.15 days, respectively. The freshly formed pupa was pinkish in colour which later turned dark brown, elongate oval in shape and had a pair of spiracles on each abdominal segment. The pupal period ranged from 7.08 to 8.08 days with an average of 7.47 ± 0.43 days during kharif 2016 and 9.16 to 10.87 days with an average of 9.96 ± 0.61 days during rabi 2016-17. The average longevity of male was 3.32 ± 0.22 and 4.03 ± 0.67 days while that of female was 4.58 ± 0.16 days and 5.41 ± 0.33 days, respectively during kharif and rabi seasons. The total life cycle of the shoot borer on potato (egg to adult emergence) occupied 29.72 to 32.92 days with a mean of 31.79 ± 1.16 days during kharif 2016 and 35.05 to 39.67 days with an average of 37.52 ± 1.44 days during rabi 2016-17.