Annual life history of okra shoot and fruit borer, Earias vittella (Fabricius), under mid-hill conditions of Himachal Pradesh, India

Abstract

Annual life history of Earias vittella (Fabricius) (Lepidoptera, Nolidae), was investigated under natural laboratory conditions in the mid-hill region of Himachal Pradesh, India, during 2023–2024. The insect completed five overlapping generations annually. The duration of the active generations ranged from 31.6 to 34.6 days, whereas the overwintering generation exhibited a markedly prolonged developmental period of 200.4–229.5 days. The mean incubation, larval and pupal periods during the active generations were 3.4 ± 0.05, 14.0 ± 0.44 and 8.3 ± 0.24 days, respectively, while the overall mean developmental period was 87.7 ± 38.7 days. Adult females survived longer than males, with mean longevities of 6.1 ± 0.20 and 5.3 ± 0.10 days, respectively. Mean fecundity was 147.8 ± 21.60 eggs per female but declined markedly during the overwintering generation. Egg, larval and pupal survival were also reduced under winter conditions, resulting in lower growth indices than those recorded during the active generations. The findings demonstrate that seasonal temperature profoundly influences the annual life history, survival and reproductive potential of E. vittella. The study provides baseline information for forecasting pest incidence and developing timely, location-specific integrated pest management strategies for okra under the mid-hill agroclimatic conditions of Himachal Pradesh.