Identification of Dialeurodes citri as a Vector of Citrus yellow vein clearing virus in China

In 2009, a new citrus viral disease caused by Citrus yellow vein clearing virus (CYVCV) was first discovered in China and now CYVCV is widely distributed in the field. CYVCV is transmissible by grafting and is spread by aphids from lemon to bean, and from bean to bean. However, until now, no vector has been shown to transmit CYVCV from citrus to citrus. In this study, after a 24-h acquisition access period (AAP), CYVCV was tested for in Dialeurodes citri (Ashmead), Panonychus citri McGregor, and Aphis citricidus (Kirkaldy) by quantitative RT-PCR. After an AAP of 48 h, groups of adults of D. citri, P. citri, and A. citricidus were given a 48 h inoculation access period on cultivar Daidai sour orange seedlings. Three, 6, and 12 months post-transmission by D. citri, CYVCV was detected in the receptor plants, and the mean incidence of infected trees was 31.9, 39.1, and 39.1%, respectively. CYVCV was not transmitted to citrus by P. citri or A. citricidus. This is the first report of the ability of D. citri to transmit CYVCV from infected to healthy citrus under laboratory conditions.