Ecology, host plant resistance, and management of paddy black beetle (Heteronychus lioderes) in rice under north-western Himalayan conditions

The paddy black beetle, Heteronychus lioderes Redtenbacher, has emerged as an important soil-dwelling pest in rice ecosystems of the north-western Himalayas. This study evaluated its population dynamics, host plant resistance, and management under mid-hills field conditions. The pest appeared in late July and peaked in early August, causing up to 48.4% tiller infestation. Population build-up showed significant positive correlation with minimum temperature, relative humidity, and rainfall. Screening of 60 rice genotypes revealed no highly resistant entries, although T-23 and Vallabh Basmati-24 exhibited moderate resistance. Among management options, Chlorpyrifos was most effective, recording lowest infestation (13.18%) and highest grain yield (35.33 q ha⁻¹), followed by carbofuran and clothianidin. Botanical treatments were less effective but offered eco-friendly alternatives. The study highlights the importance of integrating climatic monitoring, host resistance, and timely interventions for sustainable management of H. lioderes.