Expression of cytoplasmic incompatibility and host fitness effects in field populations of Sogatella furcifera infected with Cardinium.

'Candidatus Cardinium' is a maternally inherited intracellular bacterium that infects a wide range of arthropods and causes diverse reproductive alterations of its arthropod hosts, including cytoplasmic incompatibility (CI), parthenogenesis and feminization. CI is the most common effect and is expressed as a reduction in the number of offspring in crosses between infected males and uninfected females (or females infected with a different bacterial strain). The white-backed planthopper Sogatella furcifera (Horváth) is a major rice pest in Asia and is a vector of the Southern rice black-streaked dwarf virus (SRBSDV). In this study, we found severe CI expression induced by Cardinium in Yunnan and Guangxi populations of S. furcifera by performing four crosses of Cardinium-infected (C) and uninfected (U) planthoppers: female U x male U, female U x male C, Female C x Male U, Female C x Male C. Investigations of the fitness costs and benefits of Cardinium infection in these populations showed that it had no effect on the fecundity of females, but could shorten the developmental time of nymphs.