Temporal Dynamics and Seasonal Incidence of Major Insect Pests in Castor (Ricinus communis L.) under Tropical Agro ecosystem of Tamil Nadu
Résumé
An intensive four-year field study (2013–2017) was conducted at Tapioca and Castor Research Station, Tamil Nadu Agricultural University, to monitor the seasonal incidence and population dynamics of major insect pests infesting castor (Ricinus communis L.). Weekly observations revealed that leafhoppers (Empoasca flavescens) were the dominant sucking pest, initiating infestation from the seedling stage and peaking between the 50th and 52nd standard weeks. Defoliators such as Achaea janata, Spodoptera litura, Euproctis fraterna, and Ergolis merione appeared sporadically, with capsule borer (Conogethes punctiferalis) damage observed from spike initiation onward. Significant late-stage infestations of thrips (Retithrips syriacus) and whiteflies (Trialeurodes ricini) were also documented. Pest incidence patterns closely followed crop phenology and weather variables. The findings are crucial for designing location-specific Integrated Pest Management (IPM) strategies in castor agroecosystems.