Genus Falsorsidis Breuning, 1959

Falsorsidis Breuning, 1959: 82. Type species: Orsidis griseofasciatus Pic, 1926, by original designation.

Falsorsidis: BREUNING (1963: 503), BREUNING (1975: 8, 45).

Complementary description to the original description provided by BREUNING (1959). Elongate. Maxillary and labial palpi with terminal palpomeres showing sexual dimorphism (distally broadened in male and fusiform in female). Frons transverse. Eyes coarsely faceted, deeply emarginate; lower eye lobes vertical. Antennal tubercles moderately prominent. Antennae long and slender, longer than body in both sexes; antennomere III much longer than IV or scape. Scape lacking cicatrix. Pronotum transverse; sharply spinose laterally. Elytra long, parallel, rounded at apices. Hindwings developed. Prosternal process narrow, lower than coxae. Mesoventral process without tubercles, obliquely declivous anteriorly. Mesocoxal cavities open externally to mesepimera. Metaventrite not shortened. Legs long; femora clavate; mesotibiae provided with slight dorsal groove; tarsi tetramerous; tarsal claws divaricate. Endophallus with cs developed; apical furrow with internal membrane complete; ejaculatory ducts paired and associated with pair of rod-like sclerites.

Comments to classification. This genus was established by BREUNING (1959) based on Orsidis griseofasciatus Pic, 1926 from Tonkin, Vietnam. In the original description BREUNING (1959) considered it allied with Diboma Thomson, 1864 (= Zotalemimon Pic, 1925), and later (BREUNING 1963, 1975) placed it in the tribe Rhodopinini, mainly based on the scape without an apical cicatrix. However, comprehensive investigation of new material of F. griseofasciatus recently discovered in Guangxi, China shows that this species simultaneously possesses tetramerous tarsi (tarsomeres 4 and 5 completely fused) and paired ejaculatory ducts, a combination of characters only known in certain genera of the Lamiini-Dorcadionini but not in Rhodopinini or Desmiphorini (ŠVÁCHA & LAWRENCE 2014). Furthermore, F. griseofasciatus is extremely morphologically similar to the Oriental lamiine genus Granulorsidis Breuning, 1980, especially in the apical maxillary and labial palpomeres showing sexual dimorphism (Figs 1a, 2a; the type species of Granulorsidis was examined by F. Vitali, pers. comm. 2024). The similarities of endophallic structures between F. griseofasciatus and studied Granulorsidis species from Borneo (Figs 5,7; i.e., cs developed, apical furrow with internal membrane complete, ejaculatory ducts paired, APH with a pair of rod-like sclerites) also suggest a possible relationship of these genera. Based on those characters, Falsorsidis is herein transferred to the tribe Lamiini, but it differs from Granulorsidis in the scape without an apical cicatrix.