Abstract
Abstract“Open ended” or “dark taxa” are species-rich clades that are so abundant and diverse that conventional taxonomic methods tend to struggle with the onslaught of specimens and species. New approaches based on presorting specimens to putative species with affordable barcodes may make tackling these taxa manageable. However, this will still require limiting the geographic scope of revisions, given that most countries and biogeographic regions will have too many specimens and species for comprehensive coverage. We demonstrate the power of this approach by carrying out a revision of the fungus gnats (Diptera: Mycetophilidae) of Singapore. The material revised here was obtained from 496 Malaise trap samples caught by 71 Malaise traps placed at 107 collecting sites in different habitats: mangroves, swamp forests, freshwater swamps, primary rainforests, and different types of secondary forests (old, maturing, young, urban). Based on molecular and morphological data for more than 1,456 specimens, we delimit 120 species with molecular and morphological data. Of these, only 4 or 5 are species previously described. The remaining 115 are new to science and described here. However, we only name only 99 species, since 14 species are currently only known from females and we cannot prepare a fully satisfying morphological diagnosis (Manotaspp. A–G andNeoempheriaspp. A–G), and two species lack molecular data (Epicyptasp. A andNeoempheriasp. H). The match ratio between morphology and standard MOTUs (3% clusters) was overall high (95%) with even higher match ratios (99%) observed for 5% Objective Clustering and MOTUs obtained with ABGD (P=0.060). Overall, the ratio of undescribed to described is an astonishing 23:1. Only revising the Singapore fauna increases the number of described species of Oriental Mycetophilidae by over 25%. This highlights the size of the taxonomic impediment for fungus gnats. Most of the Singapore Mycetophilidae diversity belongs to three of 22 genera—NeoempheriaOsten-Sacken (31 species),EpicyptaWinnertz (29 species) andManotaWilliston (14 species), but we also describe a new genus,Integricypta,gen. n.based on three species. It belongs to Mycetophilinae Mycetophilini and is the putative sistergroup ofAspidioniaColless. The species sequenced, illustrated, and named are:Leptomorphus rafflesi,sp. n.;Monoclona simhapura,sp. n.;Azana demeijeri,sp. n.;Azana leekongchiani,sp. n.(Sciophilinae);Tetragoneura crawfurdi,sp. n.;Tetragoneura chola,sp. n.;Tetragoneura dayuan,sp. n.;Tetragoneura farquhari,sp. n.;Ectrepesthoneura johor,sp. n.(Tetragoneurinae);Mohelia zubirsaidi,sp. n.;Allactoneura tumasik,sp. n.;Allactoneura limbosengi,sp. n.;Manota banzu,sp. n.;Manota tantocksengi,sp. n.;Manota bukittimah,sp. n.;Manota chiamassie,sp. n.;Manota danmaxi,sp. n.;Manota mahuan,sp. n.;Manota temenggong,sp. n.;Clastobasis sritribuana,sp. n.;Clastobasis bugis,sp. n.;Clastobasis oranglaut,sp. n.(Leiinae);Parempheriella mait,sp. n.;Parempheriella longyamen,sp. n.;Parempheriella peranakan,sp. n.;Neoempheria sachmatich,sp. n.;Neoempheria merlio,sp. n.;Neoempheria sabana,sp. n.;Neoempheria sangabo,sp. n.;Neoempheria shicheng,sp. n.;Neoempheria ujong,sp. n.;Neoempheria subaraji,sp. n.;Neoempheria kokoiyeeae,sp. n.;Neoempheria mandai,sp. n.;Neoempheria malacca,sp. n.;Neoempheria sinkapho,sp. n.;Neoempheria singapura,sp. n.;Neoempheria xinjiapo,sp. n.;Neoempheria puluochung,sp. n.;Neoempheria merdeka,sp. n.;Neoempheria neesoon,sp. n.;Neoempheria pulau,sp. n.;Neoempheria cinkappur,sp. n.;Neoempheria temasek,sp. n.;Neoempheria polunini,sp. n.;Neoempheria fajar,sp. n.;Neoempheria riatanae,sp. n.(Mycomyinae);Allodia glorialimae,sp. n.;Brachycampta murphyi,sp. n.;Brachycampta limtzepengi,sp. n.;Brachycampta teopohlengi,sp. n.;Exechia tanswiehiani,sp. n.;Exechia alinewongae,sp. n.;Mycetophila chngseoktinae,sp. n.;Mycetophila georgettechenae,sp. n.;Mycetophila aishae,sp. n.;Platyprosthiogyne phanwaithongae,sp. n.;Platyprosthiogyne gohsookhimae,sp. n.;Platyprosthiogyne rahimahae,sp. n.;Platyprosthiogyne lynetteseahae,sp. n.;Platyprosthiogyne neilaae,sp. n.;Platyprosthiogyne snehalethaae,sp. n.;Platurocypta adeleneweeae,sp. n.;Platurocypta tanhoweliangi,sp. n.;Epicypta constancesingamae,sp. n.;Epicypta jennylauae,sp. n.;Epicypta limchiumeiae,sp. n.;Epicypta janetyeeae,sp. n.;Epicypta kohkhenglianae,sp. n.;Epicypta daintoni,sp. n.;Epicypta holltumi,sp.n.;Epicypta alii,sp. n.;Epicypta ridleyi,sp. n.;Epicypta chezaharaae,sp. n.;Epicypta tanjiakkimi,sp. n.;Epicypta gehminae,sp. n.;Epicypta jackieyingae,sp. n.;Epicypta khatijunae,sp. n.;Epicypta purchoni,sp. n.;Epicypta foomaoshengi,sp. n.;Epicypta ganengsengi,sp. n.;Epicypta nanyangu,sp. n.;Epicypta nus,sp. n.;Epicypta peterngi,sp. n.;Epicypta maggielimae,sp. n.;Epicypta yupeigaoae,sp. n.;Epicypta annwee,sp. n.;Epicypta wallacei,sp. n.;Epicypta lamtoongjini,sp. n.;Epicypta catherinelimae,sp. n.;Epicypta grootaerti,sp. n.;Epicypta joaquimae,sp. n.;Aspidionia cheesweeleeae,sp. n.;Aspidionia janetjesudasonae,sp. n.;Aspidionia fatimahae,sp. n.;Integricypta fergusondavie,sp. n.;Integricypta teosoonkimae,sp. n.;Integricypta shirinae,sp. n.;Integricypta hoyuenhoeae,sp. n.(Mycetophilinae). The previously described species are:Metanepsia malaysianaKallweit,Eumanota racolaSøli,Parempheriella defectiva(Edwards), andNeoempheria dizonalis(Edwards) (all known from Sumatra and/or the Malaysian peninsula). Two females belong to a species ofChalastonepsiathat may be one of the described species of the genus. The gnoristine genusVecellaWu & Yang is here proposed as a new synonym toParempheriella, withP. guadunana(Wu & Yang),n.comb., corresponding to an additional Palearctic species of the genus. Barcodes for a second set of 1,567 specimens suggest the presence of an additional 24 MOTUs. We thus estimate that approximately 85% of all the species that routinely enter Malaise traps are here identified or described. The revision concludes with a discussion of the biogeography and generic composition of the mycetophilid fauna at the southern end of the Malay Peninsula.