Hybrids were obtained from a cross between Nephotettix virescens females and N. cincticeps males; 17 females (24%) from 70 pairs produced fertile aggs. No hybrids were produced, however, from the reciprocal cross. Selfed F₁ hybrids (N. virescens×N. cincticeps) did not produce F₂ progenies due to F₁ hybrid male sterility. Backcross progenies were produced by crossing F₁ hybrid females with N. virescens males or N. cincticeps males. Most of the morphological characters of the hybrids in both nymphs and adults were intermediate between the parents. The presence of two separated thin brown dashes on both sides of the vertex in the adult hybrid male was the most reliable criterion to distinguish it from its parental species. Mortality of the hybrid nymphs on the Indica rice variety, Te-tep, resistant to N. cincticeps but susceptible to N. virescens, and on foxtail grass, a major winter host plant of N. cincticeps, was intermediate between that of the parents. In a test on the transmission of persistent rice virus diseases, the percentage of active transmitters among the hybrids was very low for the rice dwarf virus (RDV), and was intermediate for the rice transitory yellowing virus (RTYV) between the parental species. N. cincticeps transmitted both viruses efficiently, but N. virescens was unable to transmit RDV and was a poor transmitter of RTYV. Therefore, virus transmissibility appears to be inherited in an interspecific cross.