ABSTRACT
The biological transmission of Tomato Venezuela virus (ToVEV) by biotype B of the whitefly species Bemisia tabaci (Gennadius) increased (21.7-95.0 percent), and the time for symptom expression decreased (16-12.6 days) as the number of viruliferous whiteflies allowed access for inoculation to susceptible tomato plants increased from 1 to 20 adults/plant. When acquired only as a nymph, adults of this biotype transmitted the virus to 88.3 percent of susceptible tomato plants, using 15 viruliferous individuals per test plant, corroborating the circulative nature of the transmission. Disease incidence further increased (up to 100 percent) when the individuals were allowed to feed again on a virusinfected plant as adults. Leaf area, plant height and dry matter were significantly affected in ToVEV infected tomato plants.