BIOLOGY AND FRUIT INFESTATIONS OF FRUIT BORER, HELICOVERPA ARMIGERA (LEPIDOPTERA: NOCTUIDAE) ON TOMATO

Abstract

Tomato fruit borer, Helicoverpa armigera (Hubner) is one of the most destructive pests of tomatoes throughout the world. The experiment was carried out on BARI tomato 2 (Ratan) in an ambient temperature under laboratory conditions (25 ± 2°C, 60-70 % RH and 13-14 h light: 11-10 h dark). The average life cycle of males and females was 49.2 days and 50.8 days, respectively. The sex ratio was 0.52 and the average longevity of male and female was 11.1 days and 11.5 days, respectively. In the life table parameters, the following variables were measured: intrinsic rate of natural increase (rm), 0.10 females/female/day; mean generation time (T), 47.747 days; net reproductive rate (R0), 119.294 individuals; finite rate of increase (λ), 1.105 females/female; and population doubling time (DT), 6.921 days. The number of infested fruits was the highest (1.91) at 3 rd week of March and the lowest (0.69) at 1st week of March. The highest and the lowest number of healthy fruits (15.20) and (13.13) were observed at 1st and 3rd week of March, respectively. The percent fruit infestation was higher (12.29%) at 3rd week of March on BARI tomato 2 which is significantly differ from all other observation dates. Greater knowledge of life history traits and natural fruit infestation of this species is needed in order to design appropriate management strategies.