Population Dynamics of Insect Pests of Coriander and their Correlation with Biotic and Abiotic Factors

Field investigations during rabi 2022–23 and 2023–24 revealed the population dynamics of insect-pests and their natural predator on coriander. Among insect pests, coriander aphid (Hyadaphis coriandri Das) was recorded as the major pest, while whitefly (Bemisia tabaci Genn.), thrips (Thrips tabaci Lindeman) and mite (Petrobia latens Muller) occurred in low numbers and were identified as minor pests. Aphid infestation initiated from the second to third week of January and peaked in late February, coinciding with maximum temperatures of 23.2–24.5°C, minimum 3.5–4.9°C, and relative humidity 55.0–55.5%. Aphid population showed significant positive correlation with maximum temperature and coccinellid predator (Coccinella septempunctata Linn.) abundance, but negative correlation with relative humidity. The predator appeared in late January and peaked in February (14.2–15.8 beetles/5 plants). Coccinellid population showed positive correlation with temperature and non-significant response to relative humidity. Thus, C. septempunctata was the key biological control agent of H. coriandri in coriander ecosystems