A review of Plateros Bourgeois, 1879 of Indochina (Coleoptera: Lycidae)

The first species of the genus Plateros Bourgeois, 1879, one of the largest in the family of net-winged beetles and one of the most widespread, which includes over 900 species distributed in all biogeographic realms, mostly in the Palaeotropics (e.g., Kleine, 1933; Kazantsev, 2011), was registered in Indochina in the second half the nineteenth century [Fairmaire, 1888]. Later on, however, this species, P. sycophanta Fairmaire, 1888, was found to be conspecific with P. chinensis Waterhouse, 1879, described from China [Bocáková, 1997]. Many more species and ‘varieties’ of the genus were added to the regional fauna in the first half of the twentieth century, mostly from ‘Tonkin’ (northern Vietnam), ‘Annam’ (central Vietnam) and ‘Cochin/ Cochinchina’ (southern Vietnam). All of these were introduced by the French coleopterist Maurice Pic who described 38 species-level taxa from the region [Pic, 1916, 1921, 1923, 1925, 1926, 1927, 1931, 1938, 1939, 1942]. The study of the Indochinese Plateros was resumed only in the twenty first century [Kazantsev, 2005, 2011, 2017], and increased the total number of species of the genus registered in the region to over seventy. Until in the XXI century, however, when it was demonstrated that it is the male genital structures that can actually help separate species of the genus, the Indochinese Plateros taxa were distinguished only by coloration and form of their body, pronotum and antennae. This had led to a situation when many similarly looking species remained undescribed, and, by contrast, certain colour forms of a single species happened to be described as distinct taxa. ABSTRACT. Twenty new species of the genus Plateros Bourgeois, 1879, P. abbreviatus, P. anguliplanatus, P. baolokensis, P. bellipratensis, P. gemellus, P. gerstmeieri, P. huaphanensis, P. leptohelix, P. macroimpressus, P. macrolycoides, P. magnicauda, P. phoupanensis, P. planatomimus, P. proplanatus, P. raotensis, P. sarmentosus, P. siniaevi, P. stenohelix, P. tamdaoensis and P. xalinhensis spp.n., are described from Vietnam, Laos, Thailand and Cambodia. Plateros elisus Pic, 1921, syn.n. and Plateros annamitus Pic, 1921, syn.n. are synonymized with P. chinensis Waterhouse, 1879; P. elongatissimus var. bicolorithorax Pic, 1926, syn.n. — with P. elongatissimus Pic, 1923 and Ditoneces tonkineus var. discicollis Pic, 1942, syn.n. — with Ditoneces tonkineus Pic, 1931 [Plateros ciceroi Kazantsev, 2011]. Plateros lacosus var. obscurior Pic, 1938 is raised to Plateros obscurior Pic, 1938, stat.n. and Plateros nitidus var. reductetestaceus Pic, 1938 — to Plateros reductetestaceus Pic, 1938, stat.n. Provided is an illustrated review of Indochinese Plateros.