An integrative taxonomic treatment of the Mycetophilidae of Singapore reveals 115 new species from just 730 km 2 (Diptera: Bibionomorpha)

Here, we present a case study of this type approach by carrying out a revision of the Mycetophilidae (Diptera), or fungus gnats, of Singapore with a reverse taxonomy workflow. The studied material was obtained from 496 samples collected with 71 Malaise traps placed at 107 sites in a variety of habitats in the country: mangroves, a swamp forest, freshwater swamp, primary rainforests, a coastal forest, and different types of secondary forest (old, maturing, young, urban).

Based on molecular and morphological data for 1,454 specimens, we were able to delimit 120 species belonging to 23 genera. Of these, only five species had been previously described. The remaining 115 are new to science and described here.

However, we only name 98 of these species, since 14 (Manota spp. A –G, Neoempheria spp. A –G) were represented solely by females from which we could not prepare a fully satisfactory morphological diagnosis, and three lacked molecular data (Epicypta sp.

A, Epicypta sp. B, and Neoempheria sp. H).

To assess congruence among species delimited by DNA barcodes (3% clusters) and morphology, we calculated match ratio and found it to be overall high across the entire family (95%), with even higher ratios (99%) for MOTUs clustered at 5% with Objective Clustering and MOTUs obtained with ABGD set to P=0.060. Overall, the ratio of undescribed to described species was an astonishing 20:1. Our revision of the Singapore fauna alone, we were able to increase the number of described Oriental Mycetophilidae species by about 25%, underscoring the magnitude of the taxonomic impediment for fungus gnats.

Most of the Singapore Mycetophilidae belong to three genera: Neoempheria Osten-Sacken (29 species), Epicypta Winnertz (29 species), and Manota Williston (14 species) but we also describe a new genus, Integricypta Amorim & Oliveira gen. n. (Mycetophilinae: Mycetophilini), the putative sister-group of Aspidionia Colless, based on three species. The new species formally named here are: Leptomorphus rafflesi Amorim & Oliveira sp. n.; Monoclona simhapura Amorim & Oliveira sp. n.; Azana demeijeri Amorim & Oliveira sp. n.; Azana leekongchiani Amorim & Oliveira sp. n.

(Sciophilinae); Tetragoneura crawfurdi Amorim & Oliveira sp. n.; Tetragoneura chola Amorim & Oliveira sp. n.; Tetragoneura dayuan Amorim & Oliveira sp. n.; Tetragoneura farquhari Amorim & Oliveira sp. n.; Ectrepesthoneura johor Amorim & Oliveira sp. n. (Tetragoneurinae); Mohelia zubirsaidi Amorim & Oliveira sp. n.; Allactoneura tumasik Amorim & Oliveira sp. n.; Allactoneura limbosengi Amorim & Oliveira sp. n.; Manota banzu Amorim & Oliveira sp. n.; Manota tantocksengi Amorim & Oliveira sp. n.; Manota bukittimah Amorim & Oliveira sp. n.; Manota chiamassie Amorim & Oliveira sp. n.; Manota danmaxi Amorim & Oliveira sp. n.; Manota mahuan Amorim & Oliveira sp. n.; Manota temenggong Amorim & Oliveira sp. n.; Clastobasis sritribuana Amorim & Oliveira sp. n.; Clastobasis bugis Amorim & Oliveira sp. n.; Clastobasis oranglaut Amorim & Oliveira sp. n.

(Leiinae); Parempheriella mait Amorim & Oliveira sp. n.; Parempheriella longyamen Amorim & Oliveira sp. n.; Parempheriella peranakan Amorim & Oliveira sp. n.; Mycomya sachmatich Amorim & Oliveira sp. n.; Neoempheria merlio Amorim & Oliveira sp. n.; Neoempheria sabana Amorim & Oliveira sp. n.; Neoempheria sangabo Amorim & Oliveira sp. n.; Neoempheria shicheng Amorim & Oliveira sp. n.; Neoempheria ujong Amorim & Oliveira sp. n.; Neoempheria subaraji Amorim & Oliveira sp. n.; Neoempheria kokoiyeeae Amorim & Oliveira sp. n.; Neoempheria mandai Amorim & Oliveira sp. n.; Neoempheria malacca Amorim & Oliveira sp. n.; Neoempheria sinkapho Amorim & Oliveira sp. n.; Neoempheria singapura Amorim & Oliveira sp. n.; Neoempheria xinjiapo Amorim & Oliveira sp. n.; Neoempheria puluochung Amorim & Oliveira sp. n.; Neoempheria merdeka Amorim & Oliveira sp. n.; Neoempheria neesoon Amorim & Oliveira sp. n.; Neoempheria pulau Amorim & Oliveira sp. n.; Neoempheria cinkappur Amorim & Oliveira sp. n.; Neoempheria temasek Amorim & Oliveira sp. n.; Neoempheria polunini Amorim & Oliveira sp. n.; Neoempheria fajar Amorim & Oliveira sp. n.; Neoempheria riatanae Amorim & Oliveira sp. n.

(Mycomyinae); Brachycampta glorialimae Amorim & Oliveira sp. n.; Brachycampta murphyi Amorim & Oliveira sp. n.; Brachycampta limtzepengi Amorim & Oliveira sp. n.; Rymosia teopohlengi Amorim & Oliveira sp. n.; Exechia tanswiehiani Amorim & Oliveira sp. n.; Exechia alinewongae Amorim & Oliveira sp. n.; Mycetophila chngseoktinae Amorim & Oliveira sp. n.; Mycetophila georgettechenae Amorim & Oliveira sp. n.; Mycetophila aishae Amorim & Oliveira sp. n.; Platyprosthiogyne phanwaithongae Amorim & Oliveira sp. n.; Platyprosthiogyne gohsookhimae Amorim & Oliveira sp. n.; Platyprosthiogyne rahimahae Amorim & Oliveira sp. n.; Platyprosthiogyne lynetteseahae Amorim & Oliveira sp. n.; Platyprosthiogyne neilaae Amorim & Oliveira sp. n.; Platyprosthiogyne snehalethaae Amorim & Oliveira sp. n.; Platurocypta adeleneweeae Amorim & Oliveira sp. n.; Platurocypta tanhoweliangi Amorim & Oliveira sp. n.; Epicypta constancesingamae Amorim & Oliveira sp. n.; Epicypta jennylauae Amorim & Oliveira sp. n.; Epicypta limchiumeiae Amorim & Oliveira sp. n.; Epicypta janetyeeae Amorim & Oliveira sp. n.; Epicypta kohkhenglianae Amorim & Oliveira sp. n.; Epicypta daintoni Amorim & Oliveira sp. n.; Epicypta holltumi Amorim & Oliveira sp. n.; Epicypta ridleyi Amorim & Oliveira sp. n.; Epicypta chezaharaae Amorim & Oliveira sp. n.; Epicypta tanjiakkimi Amorim & Oliveira sp. n.; Epicypta gehminae Amorim & Oliveira sp. n.; Epicypta jackieyingae Amorim & Oliveira sp. n.; Epicypta khatijunae Amorim & Oliveira sp. n.; Epicypta purchoni Amorim & Oliveira sp. n.; Epicypta foomaoshengi Amorim & Oliveira sp. n.; Epicypta ganengsengi Amorim & Oliveira sp. n.; Epicypta nanyangu Amorim & Oliveira sp. n.; Epicypta nus Amorim & Oliveira sp. n.; Epicypta peterngi Amorim & Oliveira sp. n.; Epicypta maggielimae Amorim & Oliveira sp. n.; Epicypta yupeigaoae Amorim & Oliveira sp. n.; Epicypta annwee Amorim & Oliveira sp. n.; Epicypta wallacei Amorim & Oliveira sp. n.; Epicypta lamtoongjini Amorim & Oliveira sp. n.; Epicypta catherinelimae Amorim & Oliveira sp. n.; Epicypta grootaerti Amorim & Oliveira sp. n.; Epicypta joaquimae Amorim & Oliveira sp. n.; Aspidionia cheesweeleeae Amorim & Oliveira sp. n.; Aspidionia janetjesudasonae Amorim & Oliveira sp. n.; Aspidionia fatimahae Amorim & Oliveira sp. n.; Integricypta fergusondavie Amorim & Oliveira sp. n.; Integricypta teosoonkimae Amorim & Oliveira sp. n.; Integricypta shirinae Amorim & Oliveira sp. n.; Integricypta hoyuenhoeae Amorim & Oliveira sp. n.

(Mycetophilinae). The previously described species collected during this study are Metanepsia malaysiana Kallweit, Eumanota racola Søli, Parempheriella defectiva (Edwards), Neoempheria dizonalis (Edwards) (all known from Sumatra and/or the Malaysian peninsula), and Chalastonepsia hokkaidensis Kallweit, a species widespread in East Asia, whose female is described here for the first time. The mycomyine genus Vecella Wu & Yang is here proposed as a junior synonym to Parempheriella Matile, syn. n., with P. guadunana (Wu & Yang), comb. n. corresponding to an additional Palearctic species of Parempheriella.

Barcodes for a second set of 1,493 Singapore mycetophilid specimens not analyzed here suggest the presence of an additional 18 MOTUs. We thus estimate that approximately 85% of all the Singapore species interceptable by Malaise traps are identified or described here. Our revision concludes with a discussion of the biogeography and generic composition of the Mycetophilidae fauna at the southern end of the Malay Peninsula.