VIEW ARTICLE

Vector Relations

The Latent Period of Beet Curly Top Virus in the Beet Leafhopper, Circulifer tenellus, Mechanically Injected with Infectious Phloem Exudate. A. C. Magyarosy, Research specialist, Department of Cell Physiology and Division of Entomology and Parasitology, University of California, Berkeley, 94720; E. S. Sylvester, professor, Department of Cell Physiology and Division of Entomology and Parasitology, University of California, Berkeley, 94720. Phytopathology 69:736-738. Accepted for publication 3 December 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-736.

The latent period of beet curly top virus (BCTV) was investigated by injecting beet leafhoppers, Circulifer tenellus, with infectious phloem exudate from spinach plants. The probability of transmission to the first test plant usually was less than that to subsequent plants, but this may have been a behavioral artifact. Transmission efficiency during short (8-9 hr) inoculation access periods (IAP) was greater per unit of time than that during long (48 hr) IAP. This suggested that only part of the feeding cycle was involved in inoculation. The cumulative proportion of first transmissions during the first six successive inoculation access periods of equal length (8 or 9 hr) following injection approximated a binomial function. The median latent period (LP₅₀), estimated to vary from 16.3 to 18.8 hr at 27 C and ~27,000 lux of continuous light, suggests that although there may be a constant probability of inoculating a plant during any one of a sequence of IAP, it is less than 1.0.