Studies on the biology of teak skeletonizer, E. machaeralis walker (pyralidae: lepidoptera) on teak Tectona grandis L. in south Gujarat (India)

Biology of teak skeletonizer, E. machaeralis Walker (Pyralidae: Lepidoptera) was studied during the year 2010–11. It was observed that the eggs were laid on upper and lower surfaces of leaves. The average length and breadth of egg was 0.27 ± 0.027 and 0.27 ± 0.028 mm, The incubation periods of eggs was 2.60 ± 0.42 days. The greenish white with yellowish brown colored head of newly hatched larva was 2.10 ± 0.24 mm long. Larval period completed in 13.16 ± 1.08 days through five in stars. Full grown larvae were 23.68 ± 1.11 mm longand 2.10 ± 0.22 mm broad, which changed their colour from green to brown or purplish. The average length and breadth of pre-pupa was 17.09 ±2.91 mm and 3 ± 0.72 mm, respectively. The pupa was formed in folded and webbed leaves. The average length and breadth of male pupa was 11.29± 0.94 mm and 2.64± 0.33 mm while, female pupa was 13.75 ± 0.70 mm and 3.61± 0.50mm, respectively. The average pre-pupal stage lasted for 2.30 ± 0.40 days. The average male pupal period was 3.92 ± 0.77 days while, that off emale was 5.64±1.13 days. Adult moths had wing span of 20 to 25 mm and their colour ranged from bright yellowish with distinct orange or pinkish transverse zig-zag lines. The pre-oviposition, oviposition and post-oviposition periods of E. machaeralis aged 1.48 ± 0.67, 4.22 ± 0.80 and 1.52 ± 0.51 days, respectively. The average longevity of female to male was 6.22 ± 0.80 and 3.13 ± 1.06 days, respectively. Total life cycle of the female and male was 25 to 32 and 20 to 28 days, respectively.