Biological Studies of Fruit Borer Helicoverpa armigera (Hub.) on Tomato Crops under Laboratory Conditions

Abstract

A laboratory study was conducted during the Rabi season of 2024–25 at Kamla Nehru Institute of Physical and Social Sciences, Sultanpur, Uttar Pradesh, to examine the biology and morphometric characteristics of the tomato fruit borer, Helicoverpa armigera. Fully grown larvae collected from unsprayed fields were reared individually on fresh tomato leaves or fruits, and observations were recorded on developmental duration, adult longevity, reproduction, sex ratio, and body measurements. The insect completed its life cycle through the egg, six larval instars, pupal, and adult stages. The total life-cycle duration ranged from 35 to 40 days, with a mean of 37.14 ± 2.60 days. The larval stage was the longest developmental phase, lasting 22.94 ± 2.60 days, while the pupal period averaged 12.53 ± 1.75 days. Adult longevity averaged 7.36 ± 1.05 days in males and 10.49 ± 1.90 days in females. The pre-oviposition and oviposition periods averaged 2.8 ± 0.75 and 8.00 ± 0.80 days, respectively. Mean fecundity was 541.6 ± 155.2 eggs per female, and the observed male-to-female sex ratio was approximately 1:1. Morphometric observations showed progressive increases in larval size from the first to the sixth instar. Adult females were larger and lived longer than males. These findings provide baseline information on the developmental and reproductive biology of H. armigera under the laboratory conditions of Sultanpur.