The Pseudo-Curly Top Disease in South Florida1

Pseudo-curly top virus (PCTV) was transmitted by infective treehoppers (Micrutalis malleifera Fowler) to the following species of plants: ragweed (Ambrosia sp.), chickweed (Stellaria medea L.), tomato (Lycopersicum esculentum Mill), nightshade (Solanum nigrum L.), tobacco (Nicotiana glutinosa L.), and jimsonweed (Datura stramonium L.). Symptoms in these plants were similar to those caused by other curly top viruses. Vector-virus relationships were studied. The acquisition threshold and inoculation threshold periods were both less than 1 hour. A latent period of between 24 and 48 hours was demonstrable. Virus retention was correlated with length of access feeding. Treehoppers given 24-hour access feeding periods acquired a higher charge of virus and also remained infective longer than those given 1 hour access feedings. There was no indication of virus multiplication in the vector. The half life of the virus was calculated to be 33 days. The vector-virus relationships resembled those of the beet leafhopper, Circulifer tenellus (Baker), and western curly top virus. No differences in vector efficiency were found between sexes.