Impact of seasonal variation on transmission efficiency of tomato leaf curl palampur virus (ToLCPMV) and morphological traits of Bemisia tabaci (Gennadius)
摘要
Tomato leaf curl Palampur virus (ToLCPMV) is a destructive plant pathogen transmitted by the whitefly Bemisia tabaci (Gennadius). Understanding how environmental factors affect virus transmission and whitefly morphology is crucial for understanding the relationship between virus acquisition and whitefly physiology. The study investigated the impact of seasonal changes on the transmission efficiency of ToLCPMV by B. tabaci, as well as their effects on whitefly morphology and sex ratio. Results showed that transmission efficiency varied significantly across seasons, with the highest rates (96.67%) in summer (32.6 °C) and the lowest (26.67%) in winter (9.3 °C). Temperature had a strong positive effect on transmission, while high humidity reduced efficiency. Rainfall had little influence, but longer sunshine hours moderately increased transmission. Whitefly settling behaviour was highest in summer (85–90%), supporting higher virus spread. Viruliferous whiteflies were smaller than non-viruliferous ones, with females showing the most size reduction. Non-viruliferous females reached 1.52 mm in summer, while viruliferous females peaked at 1.09 mm. Similar trends were seen in males. Seasonal changes also affected whitefly size, with larger individuals in warmer months. The sex ratio (female: male) varied, with viruliferous populations having more females (up to 4:1) in summer, suggesting viral influence on reproduction. These findings highlight the role of temperature and humidity in virus transmission and whitefly biology. Smaller viruliferous whiteflies may indicate a trade-off between virus maintenance and growth. Seasonal shifts in sex ratio and morphology could impact vector populations and virus spread.