Abstract
The flea beetle genus Lankaphthona Medvedev, 2001 is redescribed and a new species L.yunnantarsella sp. nov. Ruan, Konstantinov & Prathapan is described. Longitarsella Medvedev, 2009, syn. nov. and Philotarsa Medvedev, 2009, syn. nov. are newly synonymized with Lankaphthona. Philotarsalaosica Medvedev, 2009, syn. nov. is synonymized with Lankaphthonaphuketensis (Gruev, 1989). The following new combinations are proposed: Lankaphthonabinotata (Baly, 1876), comb. nov.; Lankaphthonacostata (Medvedev, 2016), comb. nov.; Lankaphthonacyanipennis (Medvedev, 2017), comb. nov.; Lankaphthonanigronotata (Jacoby, 1896), comb. nov.; Lankaphthonanotatipennis (Medvedev, 2009), comb. nov.; and Lankaphthonaphuketensis (Gruev, 1989), comb. nov., status restored. A highly specialized spoon-shaped 'appendage' is discovered on the first abdominal ventrite of males of Lankaphthonabinotata. Aedeagus of the same species has aberrant sheath-shaped phallobase encircling the median lobe. Morphology and possible function of these structures are discussed. Menispermaceae are newly reported as the host plants of the genus.