Insect Pest Dynamics of Arhar (Cajanus cajan) in Gmelina arborea-Based Agroforestry Systems

Abstract

A two-year field investigation (2019-2021) conducted at Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh, to assess insect-pest associations within Gmelina arborea-based agroforestry systems compared to sole cropping of Arhar, Cowpea, and Mustard. The study aimed to quantify pest populations, determine infestation levels, and seasonal incidence. Results from the Arhar + Gmelina arborea agroforestry system identified seven insect species. On Gmelina arborea, four major pest species were observed causing significant damage. Trunk borer (Dihammus cervinus, Coleoptera), Defoliator (Calopepla leayana, Coleoptera), Bark eating caterpillar (Indarbela quadrinotata, Lepidoptera), and Sap sucker/Tingid Bug (Tingis beesoni, Homoptera). Concurrently, three major pests were found on Arhar: Pod Borer (Helicoverpa armigera, Lepidoptera), Hairy caterpillar (Spilosoma obliqua, Lepidoptera), and Aphid (Aphis craccivora Koch, Hemiptera). This foundational data is crucial for developing robust, sustainable pest management strategies in agroforestry contexts, particularly in the face of evolving environmental challenges. Future research can leverage these findings to design integrated pest management (IPM) frameworks, enhance climate change resilience of agroforestry systems, explore the role of tree components in fostering beneficial insect populations, guide breeding efforts for pest-resistant crop and tree varieties, and facilitate the application of digital monitoring and predictive analytics for proactive pest control. Ultimately, this will contribute to improving the ecological and economic sustainability of agroforestry for regional farmers.