Seasonal occurrence of leaf miner, Chromatomyia horticola (Goureau) (Diptera: Agromyzidae) and its relation with environmental factors on Indian mustard, Brassica juncea

Field experiments were conducted at the Student Instructional Farm, College of Agriculture, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, to study the seasonal abundance of the leaf miner, Chromatomyia horticola, on Varuna variety during the rabi seasons of 2022-23 and 2023-24. The results showed that the incidence of leaf miner began in the first week of December 2022-23 and the second week of December 2023-24. The first peak occurred in the second week of January 2022-23, with 2.13 bugs per plant, and in the first week of January 2023-24, with 2.67 bugs per plant. A significantly negative correlation was found with maximum temperature (r = -0.600** and-0.537*) and minimum temperature (r = -0.467** and-0.407*), as well as with relative humidity (r = 0.476* and 0.695**). However, a non-significant negative correlation was observed with rainfall (r = -0.138NS and-0.014NS) in both years.