Temporal association between weather factors and the infestation of key insect pests in coloured cotton ecosystem

The present study aimed to assess the population dynamics of key insect pests in coloured cotton (Vaidehi-95) and observed their interaction with major meteorological parameters. Monitoring at weekly interval was carried out for sucking pests (jassids, whiteflies, thrips, and aphids), bollworms (Helicoverpa armigera and Pectinophora gossypiella), and natural enemies such as spiders and ladybird beetles. Sucking pest populations peaked during the 44 Standard Meteorological Week (SMW), with aphids displaying a consistent upward trend, while jassids, whiteflies, and thrips exhibited fluctuating peaks. Infestation by H. armigera commenced in the 36 SMW, reaching its highest levels between the 45 and 48 SMW, accompanied by considerable damage to squares and bolls. The incidence of P. gossypiella began in the 37 SMW, with maximum boll damage observed in the 50 SMW, exceeding 63% infestation. Predator populations were most abundant during the 34 to 40 SMWs, coinciding with pest presence. Correlation study indicated significant negative relationships between bollworm populations and several abiotic factors. In contrast, sucking pests exhibited mostly non-significant positive correlations with climatic factors, except for rainfall, which negatively influenced aphid and thrips populations. These findings emphasize the critical role of meteorological factors in pest dynamics and support the development of weather-based pest forecasting and insect pest management approaches for coloured cotton cultivation.