Comparative Transmission of Western X-Disease Virus by Colladonus montanus, C. geminatus, and a New Leafhopper Vector, Euscelidius variegatus1

Abstract

Euscelidius variegates (Kirschbaum) is shown to be a new leafhopper vector of Western X-disease virus (WXV). Although it breeds and feeds best on grasses, E. Variegatus will survive for weeks on other hosts. After virus acquisition feeding periods of approximately 30 days, the number of individuals transmitting virus ranged from 40 to 90%. The LP-50 (latent period-50) ranged from 30 to 47 days. In a 1960 experiment, after identical acquisition feeding periods on the same diseased celery plants, 75% of E. Variegates transmitted virus to healthy celery compared with 92% for the mountain leafhopper, Collardonus montanus (Van Daze). In a similar 1968 experiment, only 40% of the E. variegates transmitted virus compared with 92% for C. montanus and 65% for C. germinates (Van Daze). In the period between 1960 and 1968, the virus had been transmitted periodically every few months only by C. montanus.