Revision of the genus Lichtwardtia Enderlein in Southeast Asia, a tale of highly diverse male terminalia (Diptera, Dolichopodidae).

In the present paper the Oriental species of the genus Lichtwardtia Enderlein, 1912 are revised based on the type material of known species and new material from Singapore and Cambodia. A re-description and illustration of the holotype female of Lichtwardtiaziczac (Wiedemann, 1824) is given but since it has been described on the basis of a female only and its provenance India Orientalis is only a vague indication of its type locality, it is considered as a nomen dubium. All the species put as junior synonyms by Becker (1922) of L.ziczac are re-established to their original status with diagnosis: Lichtwardtiapolychroma (Loew, 1864) and Lichtwardtiaformosana Enderlein, 1912. However, L.coxalis is now also considered as a nomen dubium since the original description is too short to distinguish it from other species and the holotype female is lost. In addition a re-description and illustrations of L.hirsutiseta (de Meijere, 1916) are provided. Eight new species for science are described and illustrated: Lichtwardtiacambodiensis Tang & Grootaert, sp. n. (Cambodia), Lichtwardtiaconspicabilis Tang & Grootaert, sp. n. (Cambodia), Lichtwardtiainfuscata Tang & Grootaert, sp. n. (Cambodia), Lichtwardtiamonstruosa Tang & Grootaert, sp. n. (Cambodia), Lichtwardtianodulata Grootaert & Tang, sp. n. (Singapore), Lichtwardtiasemakau Grootaert & Tang, sp. n. (Singapore) and Lichtwardtiasingaporensis Grootaert & Tang, sp. n. (Singapore). Lichtwardtiazhangae Tang & Grootaert, sp. n. (Bali, Indonesia) is a new name for the species described by Zhang, Masunaga & Yang, 2009, as Lichtwardtiaziczac (Wiedemann, 1824). There are only a few good diagnostic non-genitalic characters for the species, but the male terminalia are distinctive, from simple to very complicated and armed structures. A key is given to the species of the Oriental region. Barcodes are provided for the Singaporean species. Although Lichtwardtia is a common genus in Southeast Asia it is generally not abundant locally. It is often found in anthropogenic disturbed habitats only. Four species are recorded from Singapore while eight species are sympatric and very abundant at the locality of Siem Reap in Cambodia.