'Fake widespread species': A new mangrove Thinophilus Wahlberg (Diptera, Dolichopodidae) from Bohol, Philippines, that is cryptic with a Singaporean species

Abstract

We here show an example of how a supposed ‘wide-spread’ species can actually be revealed as a ‘long-distance’ cryptic species complex. During a recent survey of the insect fauna of the mangroves of the San Vicente Mangrove Forest Association (SAVIMA) in Bohol, Philippines, many specimens of Dolichopodidae were collected. They were pre-sorted into putative species (3% threshold) using COI sequences obtained via next-generation-sequencing (NGS barcodes: 313 bp). The sequences were then compared to a database of sequences including more than 20,000 Southeast Asian dolichopodid specimens belonging to more than 300 species. The morphology for one such Boholano putative species cluster was superficially indistinguishable from and initially identified as Thinophilus comatus Grootaert, 2018, described and only known from the mangroves of Singapore. However, the 4.6% divergence in sequences between the Singaporean and Boholano specimens prompted a morphological re-examination which revealed minute differences in the male terminalia. The cryptic species from the Philippines is described and illustrated here as Thinophilus reizlae, new species.