Bionomics of chiku moth, Nephopteryx eugraphella Ragonot (Lepidoptera : Pyralidae) on sapota 

Abstract

Studies on bionomics of chiku moth, Nephopteryx eugraphella Ragonot (Lepidoptera: Pyralidae) were carried out at Department of Entomology, B. A. College of Agriculture, Anand Agricultural University, Anand during July to September, 2015. The female laid eggs along the midrib on under surface of tender leaves scattered or in batches. The freshly laid eggs were flat, oval in shape having one end broad and other slightly narrow and yellowish white in colour. The average length and breadth of eggs were 0.96 ± 0.02 and 0.46 ± 0.02 mm, respectively. The average incubation period was 3.60 ± 0.49 days. The average hatching percentage was 84.83 ± 6.33. The larva was passed through six instars. The length of first, second, third, fourth, fifth and sixth instar larva was 2. 72± 0.22, 4.84 + 0.25, 7.65 ± 0.26, 11.70 ± 0.36, 15.61± 0.28 and 20.71 ± 0.52 mm, whereas breadth was 0.47 ± 0.04, 0.80 ±0.13, 1.46 ± 0.05, 1.73 ±0.07, 2.09 ± 0.14 and 2.37 ± 0.11 mm, respectively. The width of the head capsule of respective instars was 0.38 ±0.01, 0.52 ± 0.03, 0. 79 ± 0.03, 1.08 ±0.10, 1.42± 0.04 and 1.71± 0.04 mm, respectively. The duration of first, second, third, fourth, fifth and sixth instar larva was 3.40 ± 0.78, 5.10 ± 0.84, 4.44 ± 0.64, 3.28 ± 0.46, 3.46 ± 0.50 and 2.80 ± 0.61 days, respectively. The total larval period was 22.48 ± 1.35 days. Fully developed larva suspended feeding, looked sluggish, wrinkled and gradually contract in length and turned into pre-pupal stage. The length and breadth of pre-pupa were 17.33± 0.40 and2.18+ 0.04 mm, respectively. The duration of pre-pupal stage was 1.72± 0.45 days. The larvae pupated between webbed leaves. The pupa was light green in colour. The length and breadth of pupal stage were 10.69 ± 0.44 and 2.78 ±0.15 mm, respectively. The length and breadth of male moth were 17.13+ 0. 75 and 18.81+ 1.59 mm, respectively. The length and breadth of female moth were 20.25 + 1.03 and 23.20 +1.07 mm, respectively. The pre-oviposition, oviposition and post oviposition periods were 1.57 ± 0.49, 4.05 ± 0.92 and 1.14± 0.69 days, respectively. The fecundity of the female was 95.90 ±14.40 eggs. The sex ratio (male: female) was 1: 1.24± 0.36. The total life span for male and female was 34.24 + 2.20 and 44.18 ± 4.20 days, respectively.