Beet curly top virus transmission by artificially fed and injected beet leafhoppers (Circulfer tenellus)

The transmission of beet curly top virus (BCTV) by leafhoppers, Circulifer tenellus, fed virus through Parafilm® membranes was compared with their transmission when injected with virus from phloem exudates of Amsinckia douglasiana. Virus uptake from ³²P-labelled test solutions and the resulting virus transmission, as measured by an infectivity index, varied widely. By contrast, insects injected with virus transmitted with similar efficiencies. If insects were fasted for 3, 5, or 7 h before a 6 h acquisition access period on test solutions, their ³²P, and presumably virus uptake, was greater than that of nonfasted insects and their variability in virus transmission decreased. The proportion of insects transmitting curly top virus, after fasting and given a 6 h acquisition access period, was similar to that of insects injected with virus. Maximum liquid uptake by the beet leafhopper occurred with a 12% sucrose solution.