Seasonal Incidence of Major Pod Borers, Helicoverpa armigera (Hubner) and Maruca testulalis in Mungbean (Vigna radiata L.) in Organic Cultivation

Abstract

The excessive use of conventional insecticides has led to resistance, resurgence, and environmental pollution. Therefore, eco-friendly approaches such as biorational insecticides are now being explored for sustainable pest management. The present study aimed to assesses Seasonal incidence of major pod borers, Helicoverpa armigera (Hubner) and Maruca testulalis in Mungbean (Vigna radiata L.) in organic cultivation. The present investigation was conducted during Kharif 2024 aimed to assess the population dynamics of major pod borer species and their correlation with prevailing meteorological parameters. mungbean variety PDM-139 (Samrat) was sown in early July, 2024 under organic cultivation practices. Observations on pest incidence were recorded weekly from sowing to harvest without pesticide application. The presence of two major pod borer species, Helicoverpa armigera and Maruca testulalis, with peak incidences observed during the 36th Standard Meteorological Week (SMW). H. armigera population was peaked at 7.40 larvae/5 plants, showing a significant negative correlation with rainfall (r = -0.493), while M. testulalis peaked at 9.46 larvae/5 plants and exhibited a positive significant correlation with temperature and humidity. These findings indicate that dry, warm, and humid conditions favor pod borer proliferation. The present study revealed that the population of Helicoverpa armigera and Maruca testulalis peaked during the mid-crop growth stage under favourable climatic conditions, particularly high temperature and humidity. Understanding their seasonal incidence can aid in timely pest management strategies. The study underscores the importance of pest-weather interactions in forecasting pest outbreaks and advocates for the inclusion of biorational insecticides and weather-based surveillance in integrated pest management (IPM) strategies.