Abstract
We investigated the distribution of tomato plants showing the symptoms of tomato yellow leaf curl virus (TYLCV) infection in relation to the population density and distribution pattern of the sweetpotato whitefly (Bemisia tabaci Genn.) in a greenhouse condition. The infected plants were found near the side windows of the greenhouse. However, when an insect-proof net (mesh size 0.4×0.4mm) was placed along the side windows, the infected plants were mainly found under the roof windows. This indicates an alteration in the mode of invasion of whiteflies into the greenhouse. Many whiteflies were caught at a height less than 1m height from the ground. After the placement of the insect-proof net, the invasion ratio in the greenhouse decreased from 25.5% to 4.5%. Then, the whiteflies enter the greenhouse mainly through the side windows. However, adopting preventive measures such as placing a net on the on the roof windows is very essential in controlling of TYLCV infection.
