Biology of Helicoverpa armigera (Hübner) on Chick peabased artificial diet under laboratory conditions

The present investigation on biology of Helicoverpa armigera reared on chick pea based semi-synthetic diet revealed that its life cycle consisted of four distinct stages i.e., egg, larva, pupa and adult. A single female produced 1135.20±162.58 eggs throughout her entire life span. The incubation period was 3.62±0.15 days with 91.60±4.51% egg viability. The larval stage was completed in 18.30±0.54 days by passing through six instars under laboratory conditions of 25±1°C temperature, 65±5% RH and 12 hrs light. The average stadial periods for first, second, third, fourth, fifth and sixth instar larvae were 2.28±0.18, 2.46±0.11, 2.72±0.17, 3.18±0.23, 3.86±0.18 and 3.80±0.14 days, respectively. The last larval instar did not moult and it contracted into a grub like pre-pupal stage which lasted for 2.12±0.08 days. The average pupal period was 10.24±0.46 days for females and 12.52±0.34 days for males. Female moths had a pre-oviposition period of 2.54±0.21 days that included sexual maturity period. The oviposition and post-oviposition period recorded were 6.60±0.53 and 1.42±0.15 days, respectively. The total life period ranged from 39 to 51 days with females having longer mean life than the males. The sex ratio of male: female was 1: 1.28.