Habitat manipulation for sustainable management of insect pests and conservation of natural enemies in tomato

Introduction Habitat manipulation is an important ecological approach within Integrated Pest Management (IPM) for enhancing natural biological control and reducing insect pest infestations in tomato-based cropping systems. This study evaluated the effects of different habitat manipulation strategies on insect pest dynamics, natural enemy conservation, productivity, and profitability. Methods A four-year field experiment (2021–2024) was conducted at CCS Haryana Agricultural University, Hisar, using a randomized block design comprising fifteen treatments involving border cropping, intercropping, ridge planting with staking, and mulching using marigold, coriander, and sunflower. Insect pest populations, natural enemy abundance, tomato equivalent yield, and Benefit (B) ratio were recorded and analyzed. Results Significant differences in insect pest incidence, natural enemy populations, and crop productivity were observed among treatments across the study period. Sole tomato cropping consistently recorded the highest infestations of aphids, whiteflies, leaf miners, and fruit borers, whereas habitat-diversified systems significantly reduced pest populations. Marigold-based treatments, particularly four rows of tomato intercropped with one row of marigold and ridge planting combined with companion crops, exhibited the lowest pest incidence and the highest abundance of syrphid flies and coccinellids. Habitat manipulation also significantly increased tomato equivalent yield and B ratio compared with sole cropping. The four-row tomato-marigold intercropping system consistently achieved the highest system productivity, while ridge planting with staking further improved yield stability and profitability. Although seasonal variations influenced pest and natural enemy abundance, the overall treatment effects remained consistent throughout the four years. Discussion The findings demonstrate that marigold-based habitat manipulation, particularly when integrated with ridge planting and mulching, effectively suppresses insect pests, conserves beneficial arthropods, and enhances crop productivity and economic returns. These results support habitat diversification as a robust, sustainable, and environmentally friendly component of Integrated Pest Management (IPM) for tomato cultivation.