A new species of the Asian lanternfly genus Saiva Distant, 1906, S. constanti Jiaranaisakul sp. nov., is described from Thailand with illustrations and distribution map. Saiva virescens (Westwood, 1842) is proposed as a senior synonym of Saiva phesamensis Ollenbach, 1928 syn. nov. and Fulgora pyrrhochlora Butler, 1874 syn. nov. is now considered as junior synonym of Pyrops cultellatus (Walker, 1857).