UTTAR PRADESH JOURNAL OF ZOOLOGY

Chilli (Capsicum spp.) is a commercially important vegetable and spice crop; however, its productivity is severely constrained by thrips infestation, particularly by the invasive South East Asian thrips, Thrips parvispinus (Karny). The present study aimed to evaluate the resistance of different chilli genotypes to T. parvispinus under natural field conditions and to identify potential sources of host plant resistance. The field experiment was conducted during 2024–2025 at the College of Horticulture, Bengaluru and the Regional Horticultural Research and Extension Centre (RHREC), University of Horticultural Sciences, Gandhi Krishi Vignana Kendra, Bengaluru, Karnataka, situated in the Eastern Dry Zone of India. A randomized complete block design with two replications was adopted to evaluate thirty-five chilli genotypes without the application of insecticides, allowing natural infestation of thrips. Observations on thrips population were recorded using the tapping method at 30, 60, 90 and 120 days after transplanting. Damage severity was assessed using the percent leaf curl index (PLI). The results revealed significant variation in mean thrips population and leaf curl severity among the genotypes. For most genotypes, the mean thrips population reached its peak at 60 days after transplanting. None of the genotypes exhibited immunity or complete resistance based on mean percent leaf curl index values. However, six genotypes such as S45, S29, S1, S31, S35 and S19 were categorized as moderately resistant due to lower mean thrips population and reduced leaf curl symptoms. The majority of genotypes were susceptible, while S8, S7, S3, S32 and S14 exhibited high susceptibility. The popular cultivars Arka Meghana and Pusa Jwala were also found to be susceptible. The study identified promising chilli genotypes with moderate resistance to T. parvispinus, which can serve as potential donor parents in resistance breeding programmes, thereby contributing to sustainable chilli production through reduced dependence on chemical insecticides.