Differences in Rice stripe virus transmission abilities of Laodelphax striatellus (Homoptera: Delphacidae) from four geographical populations

Abstract

The small brown planthopper, Laodelphax striatellus (Fallén), can transfer Rice stripe virus (RSV) to host plants, which then develop rice stripe disease. Between vectors, there are two paths for RSV transmission. In current study, we examined the horizontal, vertical and compound transmission rates (horizontal and vertical transmissions together) by L. striatellus from one non-epidemic area (Fuyang in Zhejiang province) and three epidemic areas (Yizheng and Peixian in Jiangsu province, and Donggang in Liaoning province). RSV acquisition rates for naïve L. striatellus from the four populations were not significantly different. RSV transmission rate to healthy rice plants by viruliferous L. striatellus from Fuyang population was relatively lower than those of the other three populations. For example, RSV transmission rate in Fuyang population decreased by 1 fold compared to that in Peixian population when the transmission times were 48 and 72h. It indicated that horizontal transmission ability of Fuyang population was lower. Vertical transmission rate and the compound transmission abilities of infective L. striatellus in the first generation did not differ significantly among the four populations. However, the ratio of RSV-positive offspring of an infective mother in the fourth generation of Fuyang population (84.3±2.4%) was lowest, and decreased by 10% compared to that of Peixian population. It meant that compound transmission ability of Fuyang population was significantly lower than the other three populations. The reason for the difference in transmission abilities of L. striatellus from different populations was discussed.