Population abundance of alate whitefly, Bemisia tabaci (Gennadius) in chilli (Capsicum annuum L.) ecosystem

The population abundance of alate whitefly (WF) (Bemisia tabaci Gennadius) on chilli (Capsicum annuum L.) was studied. A yellow sticky trap (YST) was used to monitor the population at MARDI Station, Jalan Kebun, Selangor from July to October 2003. The mean number of WF per YST was significantly different among the sampling dates (F =16.52, df = 15 and 112, p 0.05). The number of WF per YST was highest at 77 days after transplanting (DAT) and lowest at 7 DAT, which differed significantly (p 0.05) from the rest of the sampling dates. The environmental factors namely the rainfall amount (r =-0.186, p 0.05), sunshine duration (r =0.156, p 0.05), and relative humidity (r =-0.443, p 0.05) had no significant relationship with abundance of alate WF. However, wind speed had a strong and positive relationship (r =0.806, p 0.05) with the abundance of alate WF. Similarly, there was no significant relationship (r =0.321, p 0.05) between the number of alate WF caught on YST and crop maturity. Result of this study revealed that YST could be used to monitor WF population in chilli field ecosystem.