Chrysotus Meigen, 1824

Genus Chrysotus Meigen, 1824 View in CoL

The genus Chrysotus is very diverse with more than 550 species already known worldwide and more than 200 species known from the Oriental realm ( Yang et al., 2006; Wei, 2018; Liu et al., 2020). These small dolichopodid flies of about 2 mm in body length need microscopic identification and the male terminalia need to be dissected and examined in order to classify them into species groups ( Wei et al., 2015). In the Oriental region, many Chrysotus species coexist and many species are yet to be described. Identification of females based on morphology is almost impossible because females are all very similar-looking and are hardly ever associated with males in species descriptions. In his recent revision of the Chrysotus leigongshanus species group mainly based on material collected in the mountainous areas in southern China, Wei (2018) treated 59 species and described 56 species as new to science. Of these, 48 species were only known from the holotype male, of which none were associated with females.

The two species described in this paper do not belong to those from the Oriental region that were recently described or revised ( Wei et al., 2015; Wei, 2018; Liu et al., 2020). Moreover, both new species are exclusive mangrove species, a biotope that was never well investigated. Barcodes, which distinguish the new species from other related, cryptic species, are provided.