Fig. 1.

Vertical transmission of RGDV by viruliferous R. dorsalis. a Experimental design for vertical virus transmission assays. b, c Vertical transmission of RGDV by the laboratory reared b and the field caught c V⁺ and V⁻ leafhoppers via mating. Eggs were collected for tracing RGDV. d Maintenance and epidemic cycle of rice viral disease caused by RGDV in the field in Guangdong. e Viruliferous rates of R. dorsalis populations in different generations in Guangdong during overwintering seasons from 2013 to 2016. f Viruliferous rates in overwintering population of male or female R. dorsalis in Guangdong in 2015 and 2016. g Successive paternal and maternal transmission rates of RGDV by R. dorsalis for three generations. Data are presented as mean ± SE of three independent experiments of four mating combinations in b, c, and f, ^*P < 0.05, ^**P < 0.01; ANOVA followed by Tukey’s HSD test. Values are means ± SD of three independent experiments of four mating combinations in e and g (Student’s t test, two tailed). V⁺, viruliferous. V⁻, nonviruliferous. e, f O, the original overwintering insects collected in November, 1st, the first generation of overwintering insects collected around January, 2nd, the second generation of overwintering insects collected in late February. g 1st, the first generation, 2nd, the second generation, 3rd, the third generation