Biological characteristics of Helicoverpa armigera

The investigations revealed that single female produced 1156±1.09 eggs and the incubation period of egg was 3.76±0.08days and the size varied from 0.40 to 0.60 mm in length and 0.40 to 0.55 mm in breadth. The average duration of first, second, third, fourth, fifth and sixth instars larvae were 2.52+0.10, 2.48±0.10, 2.44+0.10, 2.83±0.07, 3.52+0.10 and 3.37+0.11 days, respectively. The length and breadth of corresponding stages were 1.23±0.04 and 0.37±0.01mm, 2.88±0.11 and 0.68±0.01mm, 6.90±0.17 and 1.63±0.03mm, 11.73±0.48 and 2.76±0.04mm, 19.97+0.51 and 3.18±0.04mm and 30.50±0.36 and 3.33±0.01mm. Full-grown larvae were 30–40 mm long and had various colour and banding patterns, the head as well as prothoracic legs were brown to black. The pre-pupal duration was 2.16±0.08 days; whereas pupal period was 12.0±0.17 days. The average length and breadth of pupa were 17.00±0.28 and 5.62±0.09 mm, respectively. The males were recorded greenish-grey in colour, while females were orange-brown and difference pre-emergence periods was 9.25±0.19 days for male and 11.08+0.38 days for female of H. armigera.