Influence of weather variables on the host range and population dynamics of guava spiralling whitefly (Aleurodicus dispersus Russell) in Tiruchirappalli district of Tamil Nadu, India

A systematic survey was conducted from 2023 to 2024 across six blocks of Tiruchirappalli district, Tamil Nadu to evaluate the host range, intensity of infestation and seasonal incidence of the invasive Spiralling Whitefly (SWF) (Aleurodicus dispersus Russell). The study identified 35 plant species from 23 families as hosts for spiralling whiteflies with guava and country almond ranking as the most heavily infested hosts in this surveyed region. Infestation intensity was highest in Manikandam block (41.3%), followed by Manapparai (41.1%) and lowest in Thiruverumbur block (39.6%). The peak infestation period occurred from the first week of February to the last week of April. Correlation analysis with weather parameters revealed a significant positive correlation with temperature (maximum and minimum) and a significant negative correlation with RH (morning and evening) as well as rainfall. These findings indicate that SWF infestation is lower during the rainy season and peaks during the summer season in Tamil Nadu.