Species turnover between the northern and southern part of the South China Sea in the Elaphropeza Macquart mangrove fly communities of Hong Kong and Singapore (Insecta: Diptera: Hybotidae)

A recent survey of the mangroves around Hong Kong revealed the presence of seven species of the genus Elaphropeza Macquart, 1827. All belong to a group of yellow species that occur exclusively in mangroves. Three species were previously known: Elaphropeza calcarifera Bezzi, 1912 and E. xanthocephala Bezzi, 1912, both from Taiwan, and E. riatanae Shamshev & Grootaert, 2007 from Singapore. Four species are new to science: Elaphropeza furcatella sp. nov., E. guenardi sp. nov., E. hongkongensis sp. nov. and E. hongshulin sp. nov. All seven species are described or an extended diagnosis is provided. All species are figured and NGS barcodes are made available. A key is given for the Hong Kong species and their siblings from Singapore and Taiwan. Remarkable is that five of the seven species are more or less closely related to species occurring in Singapore. Genetic distances and morphologic differences are congruent. The species turnover between the northern part and the southern part of the South China Sea is high, with only one of the seven species present in both regions