Just a Fragment of Undescribed Diversity: Twenty New Oriental and Palearctic Species of Sciaroidea (Diptera), including DNA Sequence Data and Two New Fossil Genera

Simple Summary Two-winged flies (Diptera) are one of the megadiverse insect orders, in terms of biodiversity. The suborder Nematocera (=lower Diptera) includes several particularly species-rich groups, such as fungus gnats (Mycetophilidae and related families of the superfamily Sciaroidea) and gall midges (Cecidomyiidae), the latter presumably even being the most diverse family of Diptera of all. Although every year dozens of new species from these families are being described, either from extant fauna or from the fossil record, an amazing number of species still remain undescribed, especially outside Europe or North America. In this paper, another portion of new taxa of fungus gnats is described, enabling to better understand the fascinating and still little-known world of insects on Earth. Abstract The following 17 extant new species of Sciaroidea (Diptera: Bibionomorpha) are described: Bolitophila nikolae Ševčík sp. nov. (Bolitophilidae, Taiwan), Catocha jingfui sp. nov. (Cecidomyiidae, Taiwan), Catocha manmiaoe sp. nov. (Cecidomyiidae, Taiwan), Catocha shengfengi sp. nov. (Cecidomyiidae, Taiwan), Planetella taiwanensis sp. nov. (Cecidomyiidae, Taiwan), Diadocidia pseudospinusola sp. nov. (Diadocidiidae, Taiwan), Asioditomyia bruneicola sp. nov. (Ditomyiidae, Brunei), Asioditomyia lacii sp. nov. (Ditomyiidae, Taiwan), Ditomyia asiatica sp. nov. (Ditomyiidae, Thailand), Chetoneura davidi sp. nov. (Keroplatidae, Brunei), Euceroplatus mantici sp. nov. (Keroplatidae, Thailand), Setostylus fangshuoi sp. nov. (Keroplatidae, Taiwan), Platyceridion yunfui sp. nov. (Keroplatidae, Hainan), Terocelion adami sp. nov. (Keroplatidae, Taiwan), Hadroneura martini sp. nov. (Mycetophilidae, Taiwan), Paratinia furcata sp. nov. (Mycetophilidae, Czech Republic, Slovakia), and Nepaletricha sikorai sp. nov. (Sciaroidea incertae sedis, Thailand). Two new genera are described from the mid-Cretaceous Burmese amber, Burmasymmerus gen. nov. (Ditomyiidae, type species Burmasymmerus korneliae sp. nov., including also B. wieslawi sp. nov.), representing the first record of the family Ditomyiidae from the Mesozoic, and Burmatricha gen. nov. (Sciaroidea incertae sedis, type species Burmatricha mesozoica sp. nov.). Molecular phylogeny of Ditomyiidae, based on two DNA markers (28S, COI), as well as that of Catocha Haliday, 1833, based on the mitochondrial COI and 16S fragments, are also presented.


Introduction
Fungus gnats (Diptera: Bibionomorpha: Sciaroidea) represent one of the most speciesrich groups of Diptera [1]. The phylogenetic relationships among the families of Sciaroidea have been broadly discussed, and several hypotheses have been proposed (for a summary see Ševčík et al. [2]). Seven extant families are currently included in this superfamily: Bolitophilidae, Cecidomyiidae, Diadocidiidae, Ditomyiidae, Keroplatidae, Mycetophilidae,

Family Bolitophilidae
A small family of Sciaroidea, currently comprising some 60 extant species in a single genus Bolitophila Meigen, 1818, with two subgenera, Bolitophila s. str. and Cliopisa Ender-     DNA sequences. DNA sequences (COI and 16S mitochondrial genes) taken from the holotype (No. JSTW32) and paratype (JSTW32C) are deposited in GenBank. Their Accession numbers are in Table S1.
Etymology. This species is named after Dr. Sheng-Feng Lin (National Chung Hsing University, Taichung), who installed the Malaise trap into which type specimens of this species were collected. He also operated further Malaise traps in Taiwan and provided us with the material of Diptera from these traps.
Diagnosis. Catocha shengfengi sp. nov. belongs to the C. latipes group as it is defined by Jaschhof and Jaschhof [19]. It is very similar to C. jingfui sp. nov. For distinguishing characters, see under the latter. Both these species differ from C. incisa Jaschhof and Jaschhof by having the aedeagal teeth larger and angled lateral margin of tegmen, from C. latipes Haliday by simple, not angulate, lateral margin of tegmen and from C. latipes and C. angulata Jaschhof and Jaschhof and C. subalpina Jaschhof and Jaschhof by having all the aedeagal teeth directed obliquely posterior, not partly laterad and obliquely anteriad. It seems that C. shengfengi sp. nov. and C. jingfui sp. nov. differ from the other mentioned species by having a pair of strong sclerites flanking the posterior part of the ejaculatory apodeme but they may have been unobserved in the description; in the description of C. subalpina Figure 23F in Reference [19]) there are signs of these sclerites.
Description. Male. Wing length 2.6 mm. Head capsule, thorax abdominal tergites and terminalia brown, antenna, mouthparts, legs and abdominal sternites pale brown, wing pale yellowish brown. Head. Number of postocular long setae ca. 5. Clypeus with ca. 30 setae. Eye bridge complete, 3-4 facets wide, similar medially and laterally. 3 ocelli present, all well-developed. Maxillary palpus with 4 palpomeres, palpomere 1 with ca. 10, palpomere 2 with 2 hyalinous sensilla. Antennal flagellomere 4 with the body longer than the neck ( Figure 5B), microtrichia present only on extreme base, setae on basal part of the body many and not arranged in whorls, medially on the body a complete crenulated whorl of ca. 16 setae (broken off in the mount), on distal part of the body with an incomplete crenulated whorl of ca. 7 setae, hyalinous sensilla on the apical part of the body threebranched (on more apical flagellomeres the hyalinous sensilla are bifurcate or even simple). Wing ratio length/width 2.4. Costal break present. M-fork present, one fourth of the total length of M. Rs shorter than r-m, r-m well-developed. CuA2 roundly angularly curved on distal part. Wing membrane setose, the setae relatively numerous. Terminalia ( Figure 5A,C). Gonocoxites in dorsal or ventral view constricted on anterior half, with a weak translucent window-like part medio-ventrally on anterior half. Gonostylus ovoid, slightly longer than broad, the setosity normal, the subapical mesial tooth-like aggregation of trichia rather broad, far from the apex. Tegmen subtriangular with angulate sides. Ejaculatory apodeme posteriorly flanked by dark sclerites. The aedeagal teeth medially very small, many, dark, laterally elongate triangular in shape, dark, about 3-4 times as long as basally broad, about 10 on each side, laterodorsally 2 conspicuously larger teeth on each side. Female. Unknown.
Phylogenetic relationships. Phylogenetic relationships among the species Catocha are reconstructed in Figure 6, based on two mitochondrial DNA markers (COI and 16S). Some of the relationships are, however, insufficiently supported. The species of Catocha apparently underwent a rapid evolution, which may be difficult to reveal by these two mitochondrial markers. This tree, thus, should be considered only as preliminary, pending a more detailed molecular study of the lower gall midges as a whole.

Genus Planetella Westwood, 1840
A relatively large Holarctic genus of remarkable gall midges, representing the largest gall midges in terms of adult body size (sometimes more than 1 cm), comprising 52 described species, none of them described after the year 1926 [17]. Almost all of them occur either in Europe or in North America, and they are in need of revision, focused on detailed structures of the male terminalia, in combination with DNA sequence data.

Genus Planetella Westwood, 1840
A relatively large Holarctic genus of remarkable gall midges, representing the largest gall midges in terms of adult body size (sometimes more than 1 cm), comprising 52 described species, none of them described after the year 1926 [17]. Almost all of them occur either in Europe or in North America, and they are in need of revision, focused on detailed structures of the male terminalia, in combination with DNA sequence data.
Only one species, tentatively placed in Planetella by Gagné and Jaschhof [17], was described from eastern Asia (Japan), originally as Trishormomyia bambusae Felt, 1932. The type series includes two male syntypes deposited in the National Museum of Natural History, Washington, DC, USA. According to Raymond Gagné (pers. comm.), they do not have a forward-projecting thorax, so that the prothorax is on the same vertical plane as the forelegs, as in the more usual Cecidomyiidi. It is, thus, not certain if T. bambusae even belongs to the genus Planetella but it definitely represents a different species, and most probably also a genus, than P. taiwanensis sp. nov., described below. While all the species of Planetella, where a host plant is reliably known, are associated with Carex spp., the host of the new species described here remains unknown.  Table S1.
Etymology. The specific name refers to Taiwan, where the holotype was collected. Diagnosis. This species represents a typical species of Planetella, characterized by its large body size, ochreous coloration, and scutum produced above the head. It differs from all the other species in details on the male terminalia (especially the shape of cerci, hypoproct, and the apex of gonostylus), in combination with unique COI sequence.
Description. Male. Wing length 7.2 mm. Head. Brown, antenna pale yellowish brown, scape and pedicel little darker than flagellum, maxillary palpus pale yellowish brown. Eye bridge lacking. Antennal flagellum with 12 binodal tricircumfilial flagellomeres, apically with short uninodal flagellomere lacking circumfila. Flagellomere 4, Figure 5D loops of circumfila subequal, ca. 10 in number. Clypeus with a few ventral setae. Labrum with ca. 40 conspicuous, long, curved setae. Maxillary palpus ( Figure 5E with 2 almost equally long palpomeres, basal palpomere with ca. 10, apical palpomere with 4 setae. Thorax and legs in bad condition, greatly faded, partly collapsed and details impossible to describe; it seems that there is a dark medial line anteriorly on mesonotum, that the posterior part of pleura and all of metanotum is very dark, and trochanters are dark. Only one species, tentatively placed in Planetella by Gagné and Jaschhof [17], was described from eastern Asia (Japan), originally as Trishormomyia bambusae Felt, 1932. The type series includes two male syntypes deposited in the National Museum of Natural History, Washington, DC, USA. According to Raymond Gagné (pers. comm.), they do not have a forward-projecting thorax, so that the prothorax is on the same vertical plane as the forelegs, as in the more usual Cecidomyiidi. It is, thus, not certain if T. bambusae even belongs to the genus Planetella but it definitely represents a different species, and most probably also a genus, than P. taiwanensis sp. nov., described below. While all the species of Planetella, where a host plant is reliably known, are associated with Carex spp., the host of the new species described here remains unknown.
Planetella taiwanensis sp. nov. (Figures 3B and 5D DNA sequence. DNA sequence (COI barcode region) taken from the holotype (No. JS-PLA5) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. The specific name refers to Taiwan, where the holotype was collected. Diagnosis. This species represents a typical species of Planetella, characterized by its large body size, ochreous coloration, and scutum produced above the head. It differs from all the other species in details on the male terminalia (especially the shape of cerci, hypoproct, and the apex of gonostylus), in combination with unique COI sequence.

Family Diadocidiidae
This is a small family of Sciaroidea of uncertain phylogenetic position, currently comprising a single extant genus, with three subgenera [20]. Oriental species of Diadocidiidae were treated by Papp and Ševčík [21]. An additional species is described below.  Table S1.
Etymology. The name of the new species refers to the similarity with D. spinosula.

Family Ditomyiidae
This is a small and ancient family of Sciaroidea, currently comprising almost 100 extant species in 8 genera. Asian species of Ditomyiidae were studied in detail by Saigusa [22,23]. Additional taxa, both extant and fossil, are described below. A preliminary molecular phylogeny of the family is also presented here. Diagnosis. This species belongs to the subgenus Diadocidia sensu stricto and it is morphologically almost indistinguishable from the Palaearctic Diadocidia spinosula Tollet, 1948, sharing the same shape of tergite 9, including the strong posterior setae, and overall structure of the male terminalia. Both species differ in the shape of aedeagus, which is slightly narrower in D. pseudospinosula sp. nov., and in the structure of the apical part of the gonostylus (dorsal branch of the apical fork is shorter in the new species).
Description. Male. Wing length 4.1 mm (holotype). Head dark brown. Three ocelli, closely set on a subtriangular tubercle. Lateral ocellus larger than median one, separated from eye margin for distance about 0.8 times its diameter. Antenna with 14 flagellomeres, F1 about three times as long as broad, basally yellowish. The rest of flagellomeres dark brown, about twice as long as broad. Scape and pedicel yellowish brown, about as long as wide. Maxillary palpus with four palpomeres, their relative lengths are 1:1:2:3. Thorax all dark brown. Scutum weakly arched, setose. Scutellum with a row of subapical bristles. Mediotergite and all lateral sclerites bare. Haltere dark. Wing without markings, its membrane covered with macrotrichia. Wing venation the same as in other Diadocidia s. str. Legs mostly yellowish brown, except for darker mid and hind coxae. Femora and tibiae yellowish brown, irregularly covered with trichia. Tibial spurs (1:2:2) dark brown. Abdomen all dark brown. Terminalia ( Figure 7) dark brown. Tergite 9 subtriangular, slightly longer than broad. Gonocoxites basally fused. Gonostylus almost as long as gonocoxite, tapering, with a distinct apical fork, with its dorsal branch shorter that the ventral one.

Family Ditomyiidae
This is a small and ancient family of Sciaroidea, currently comprising almost 100 extant species in 8 genera. Asian species of Ditomyiidae were studied in detail by Saigusa [22,23]. Additional taxa, both extant and fossil, are described below. A preliminary molecular phylogeny of the family is also presented here.  An exclusively eastern Asian genus of Ditomyiidae, with only a single species hitherto described [22]. Two additional species are described below, indicating that it is a widespread genus in South-East Asia. Asioditomyia differs from the other genera of Ditomyiidae mainly in the short palpi, with only one palpomere, in the absence of both crossvein r-m and r-m fusion, and in the slightly compressed flagellomeres [22].  Table S1.

Genus Asioditomyia
Etymology. The specific is name is derived from Brunei Darussalam, where the type material was collected.
Diagnosis. This species is very similar to Asioditomyia lacii sp. nov. and A. japonica (Sasakawa, 1963). Male terminalia of A. japonica (specimen recently collected in Japan) are figured here for comparison ( Figure 8H-J). All the three species differ slightly in the shape of gonostylus (more elongated in A. bruneicola sp. nov. and A. japonica) and tergite 9 (shorter in A. bruneicola sp. nov.). A. japonica is also distinctly larger (wing length 4.5 mm), with vein R 2+3 longer.
Description. Male. Mostly brown, with yellowish markings. Wing length 3.3 mm. Head. Light brown with short black setae, areas around ocelli blackish. Three ocelli, closely set to each other, median ocellus smaller. Frontal suture present. Compound eye semiglobular, not emarginated around antennal base. Maxillary palpus yellowish brown, consisting of one segment. Antennae with 15 flagellomeres, F15 min, tapering. Flagellomeres mostly light brown with short dark setae. Scape and pedicel dark brown. Bases of antennal setae marked with a black spot. Thorax. Yellowish, with dark longitudinal stripes on sides and scutum. Mediotergite dark brown. Lateral pleura and mediotergite bare. Legs. Mostly dark brown. Coxae yellowish, apically darker. Legs covered with microtrichia and sparse setae. Tibial spurs 1:2:2. Wing hyaline, with macrotrichia on membrane. C only slightly produced, ending about one-fifth the distance between R 4+5 and M 1 . Sc short, ending free, followed by long, faint, fold line, ending free near level of base of Rs. R 2+3 long, its base basal to level of medial fork. R-m absent, the veins meeting in one point. Stem of M weak. CuA weak, setose, reaching wing margin. Abdomen mostly dark brown, with yellow basal bands on tergites 2-7. Terminalia ( Figure 8A-C). Tergite 9 small, subrectangular, cerci broad, flap-like. Gonocoxites fused, relatively short, about twice as broad as long. Gonostylus broad, more than twice as long as broad, D-shaped, tapering posteriorly, with an elongate black sclerotized process on inner edge, which is lined by numerous closely set short dark setae. Female. Unknown.  DNA sequences. DNA sequences (28S and COI barcode region) taken from the holotype (No. JSTW38) are deposited in GenBank. Its Accession number is in Table S1.
Etymology. This species is named after László Papp (1946Papp ( -2021 for his achievements in the study of Oriental Diptera. He was an excellent Hungarian dipterist and a very friendly man, who inspired the first author of this paper to study Taiwanese Diptera. The specific name is derived from "Laci", a domestic form of the name László. Diagnosis. This species is very similar to Asioditomyia bruneicola sp. nov. and A. japonica (Sasakawa, 1963). The gonostylus is slightly less elongated than in A. bruneicola sp. nov. and A. japonica, and tergite 9 is longer than in A. bruneicola sp. nov.
Description. Male. Mostly brown, with yellowish markings. Wing length 3.1 mm. Head. Light brown, areas around ocelli blackish. Three ocelli, in a transverse row, median ocellus smaller. Compound eye not emarginated at antennal base. Maxillary palpus yellowish brown, with one visible basal segment. Antennae with apical flagellomeres missing. Flagellomeres mostly light brown with short dark setae. Scape and pedicel dark brown. Thorax. Yellowish, with dark longitudinal stripes on sides and scutum. Mediotergite dark brown. Lateral pleura and mediotergite bare. Legs. Mostly dark brown. Coxae yellowish, apically darker. Legs covered with microtrichia and sparse setae. Tibial spurs 1:2:2. Wing the same as in A. bruneicola sp. nov. Abdomen mostly dark brown, with yellow basal bands on tergites 2-4. Terminalia ( Figure 8D-G). Tergite 9 as long as wide, cerci flap-like. Gonocoxites fused, relatively short, about twice as broad as long. Gonostylus broad, less than twice as long as broad, D-shaped, tapering posteriorly, with a short black sclerotized process on inner edge, which is lined by numerous closely set short dark setae. Female. Unknown.
Diagnosis. Wing length approximately 1.8 mm. Wing venation similar to that of Symmerus Walker, 1848. Wing relatively broad, with ratio of length to width about 2.5. Macrotrichia on wing membrane restricted to the distal third of the wing. Vein R 2+3 relatively short, about half as long as R 5 , r-m present or absent, CuP and anal vein weak. Antennae with 14 or 15 laterally compressed flagellomeres. Male terminalia with gonostyli as long as gonocoxites, narrow, slightly expanded distally and apically rounded.
Discussion. The placement of this genus in Ditomyiidae is based on the following characters: vein R 2+3 present and relatively long (about half as long as R 5 ), Sc ending free and apically weak, R 4 absent, r-m fusion absent, stem of M-fork relatively long (more than half of M 1 ), macrotrichia on wing membrane present. Concerning the wing venation, the new genus is most similar to the extant genus Symmerus Walker, differing in the considerably smaller body size, shorter wings, shorter R 2+3 , the absence of macrotrichia in basal half of wing, vein CuP not reaching wing margin, and simpler structure of the male terminalia.
The family Ditomyiidae has not been recorded from the Burmese amber previously, neither from any other Mesozoic amber or deposits. It is, thus, the oldest geological record of the family. Ansorge [24] established a new family Eoditomyiidae from the lower Jurassic of Germany, including only the type genus Eoditomyia Ansorge, 1996, but this genus differs from Burmasymmerus gen. nov. mainly in the presence of both R 2+3 and R 4 .  Etymology. This species is named after Prof. Wiesław Krzemiński (Institute of Systematic and Evolution of Animals, Polish Academy of Sciences, Kraków) for his achievements in the study of fossil Diptera.
Diagnosis. This species differs from B. korneliae sp. nov. mainly by 15-segmented antennal flagellum, the absence of crossvein r-m, and in the shape of medioventral process of gonocoxites.
Description. Wing length 1.6 mm (holotype). Body all dark brown. Head. Three ocelli placed on a frontal tubercle, median ocellus much smaller. Compound eye oval, not distinctly emarginated at antennal base, bridge above the antennae not discernable. Palpi with three visible segments. Antennae with 15 flagellomeres, about as long as wide, laterally compressed, the apical flagellomere narrow, about half as broad as flagellomere 14. Scutum and scutellum with long dense setae. Thoracic pleura and mediotergite bare. Coxae and femora dark brown, the rest of legs brown. Legs with dense microtrichia. Several sparse posterior setae on mid and hind tibia, shorter than maximum tibial diameter. Tibial spurs 1:2:2. Wing hyaline, its membrane covered with microtrichia, plus sparse macrotrichia in distal half of the wing. C distinctly produced, ending slightly more than onethird the distance between R4+5 and M1. Sc short, ending free, followed by long faint fold line. R2+3 about half as long as R5. R-m absent. Stem of M-fork weak. CuP long but weak, setose, reaching wing margin. Abdomen dark brown. Terminalia ( Figure 10D,F) with Etymology. This species is named after Dr. Kornelia Skibińska (Institute of Systematic and Evolution of Animals, Polish Academy of Sciences, Kraków) for her achievements in the study of fossil Diptera.
Diagnosis. This species is easily recognizable by its relatively long crossvein r-m, typical of the extant genus Symmerus, and by the 14-segmented antennal flagellum. Further diagnostic characters are the long, mediobasal projection of the gonostylus, subapically constricted gonostylus, and the shape of the medioventral process of gonocoxites.
Description. Wing length 1.8 mm. Body all dark brown. Head. Three ocelli placed on a frontal tubercle, median ocellus much smaller. Compound eye oval, emarginated at antennal base, forming an incomplete bridge above antennae. Palpi with three segments. Antennae with 14 flagellomeres, about as long as wide, laterally compressed. Scutum and scutellum with long dense setae. Thoracic pleura and mediotergite bare. Coxae dark brown, rest of legs light brown. Legs with dense microtrichia. Several sparse posterior setae on mid and hind tibia, shorter than maximum tibial diameter. Tibial spurs 1:2:2. Wing hyaline, its membrane covered with microtrichia, plus sparse macrotrichia in distal half of the wing. C distinctly produced, ending about one-third the distance between R 4+5 and M 1 . Sc short, ending free, followed by long faint fold line. R 2+3 about half as long as R 5 . R-m present, as long as m-m. Stem of M-fork weak. CuP long but weak, setose, reaching wing margin. Abdomen dark brown. Terminalia ( Figure 10A,E) with tergite 9 short, about as long as broad, cerci longer than tergite 9, narrow and apically pointed. Gonocoxites fused, with the medioventral process narrow, forked, longer than gonocoxite. Gonostylus as long as gonocoxite, with distinct ventrobasal projection and subapical constriction. Posterior margin of gonostylus rounded.
Discussion. As mentioned in the Diagnosis above, this species is characteristic with its 15-segmented antennal flagellum and the absence of crossvein r-m. Both these character states are typical also of the extant genus Asioditomyia, see above, which differs from Burmahesperinus gen. nov. mainly by the much longer vein R2+3, completely setose wing, and broader gonostyli. However, we consider as premature to establish here a separate genus for B. wieslawi sp. nov., until more specimens are available and the real diversity of Burmese amber Ditomyiidae is better known.  Etymology. This species is named after Prof. Wiesław Krzemiński (Institute of Systematic and Evolution of Animals, Polish Academy of Sciences, Kraków) for his achievements in the study of fossil Diptera.
Diagnosis. This species differs from B. korneliae sp. nov. mainly by 15-segmented antennal flagellum, the absence of crossvein r-m, and in the shape of medioventral process of gonocoxites.
Description. Wing length 1.6 mm (holotype). Body all dark brown. Head. Three ocelli placed on a frontal tubercle, median ocellus much smaller. Compound eye oval, not distinctly emarginated at antennal base, bridge above the antennae not discernable. Palpi with three visible segments. Antennae with 15 flagellomeres, about as long as wide, laterally compressed, the apical flagellomere narrow, about half as broad as flagellomere 14. Scutum and scutellum with long dense setae. Thoracic pleura and mediotergite bare. Coxae and femora dark brown, the rest of legs brown. Legs with dense microtrichia. Several sparse posterior setae on mid and hind tibia, shorter than maximum tibial diameter. Tibial spurs 1:2:2. Wing hyaline, its membrane covered with microtrichia, plus sparse macrotrichia in distal half of the wing. C distinctly produced, ending slightly more than one-third the distance between R 4+5 and M 1 . Sc short, ending free, followed by long faint fold line. R 2+3 about half as long as R 5 . R-m absent. Stem of M-fork weak. CuP long but weak, setose, reaching wing margin. Abdomen dark brown. Terminalia ( Figure 10D,F) with tergite 9 short, about as long as broad, cerci much longer than tergite 9, strongly sclerotized, with branches apically pointed. Gonocoxites fused, with the medioventral process narrow, relatively short, apically with a shallow depression, not distinctly forked. Gonostylus as long as gonocoxite, without any ventrobasal projection and without distinct subapical constriction.
Discussion. As mentioned in the Diagnosis above, this species is characteristic with its 15-segmented antennal flagellum and the absence of crossvein r-m. Both these character states are typical also of the extant genus Asioditomyia, see above, which differs from Burmahesperinus gen. nov. mainly by the much longer vein R 2+3 , completely setose wing, and broader gonostyli. However, we consider as premature to establish here a separate genus for B. wieslawi sp. nov., until more specimens are available and the real diversity of Burmese amber Ditomyiidae is better known.

Genus Celebesomyia Saigusa, 1973
A monotypic genus, with only one species hitherto described [23]. Here, we present a figure of the male terminalia of this species for the first time. This genus differs from the other genera of Ditomyiidae mainly in the absence of ocelli.  Table S1.

Celebesomyia inocellata
Discussion. This species was described based on a single female collected in Central Sulawesi [23], and no corresponding male has been known up to the present. The figure of the male terminalia ( Figure 11A,B) shows its rather similar structure to Asioditomyia species. Species of Asioditomyia and Celebesomyia form a monophyletic group also in the molecular tree of Ditomyiidae, based on 28S and COI gene fragments (Figure 12), confirming that these two genera are closely related, if not identical. As noted already by Saigusa [23], Celebesomyia "most resembles the genus Asioditomyia in every structure" and "is almost certainly an offspring of the extinct Asioditomyia species which invaded into Celebes from the South Eastern Asia". The generic concept of Ditomyiidae has not been fully resolved yet, as recently commented on by Fitzgerald [25], and further phylogenetic studies, covering all the genera in this family, may change current classification.

Genus Ditomyia Winnertz, 1846
Type genus of the family Ditomyiidae, with 11 species currently described from the Holarctic region, and one from Guatemala [25]. An additional species is described below.   Table S1.
Etymology. The specific is name is derived from Asia, referring to the continent where this species occurs.
Diagnosis. This species is characteristic with its dark coloration, narrow gonostyli, and large medioventral lobe of gonocoxites.

Genus Ditomyia Winnertz, 1846
Type genus of the family Ditomyiidae, with 11 species currently described from the Holarctic region, and one from Guatemala [25]. An additional species is described below.
Etymology. The specific is name is derived from Asia, referring to the continent where this species occurs.
Diagnosis. This species is characteristic with its dark coloration, narrow gonostyli, and large medioventral lobe of gonocoxites.
Description. Male ( Figure 3C). Mostly dark brown. Wing length 4.5 mm. Head. Dark brown with short black setae, areas around ocelli blackish. Three dorsomedial ocelli, arranged in a transverse line, median ocellus much smaller. Frontal suture present. Compound eye semiglobular, not emarginated at antennal base. Maxillary palps brown, twosegmented with basal segment stout, and apical segment smaller. Antennae with 15 flagellomeres, F15 min, tapering. Flagellomeres mostly light brown with short dark setae. Pedicel and scape brown. Bases of antennal setae marked with a black spot. Thorax. All uniformly dark brown with mediotergite lighter. Scutum with long dark setae laterally and in dorsocentral rows. Scutellum with a row of subapical setae. Thoracic pleura and mediotergite bare. Legs. Coxae dark brown, the rest of legs light brown. Legs with dense microtrichia. A row of sparse black posterior setae running nearly full length of hind tibia. Tibial spurs 1:2:2. Wing hyaline and darkened, with macrotrichia on the membrane, but mostly concentrated near the wing tip and front margin. C ending about one-fourth the distance between R4+5 and M1. Sc short, ending free, followed by long, faint, fold line, ending free near level of base of Rs. R2+3 long, base basal to level of medial fork. R-m present but short. Stem of M weak. Anal vein long, setose, reaching wing margin. Abdomen. Description. Male ( Figure 3C). Mostly dark brown. Wing length 4.5 mm. Head. Dark brown with short black setae, areas around ocelli blackish. Three dorsomedial ocelli, arranged in a transverse line, median ocellus much smaller. Frontal suture present. Compound eye semiglobular, not emarginated at antennal base. Maxillary palps brown, two-segmented with basal segment stout, and apical segment smaller. Antennae with 15 flagellomeres, F15 min, tapering. Flagellomeres mostly light brown with short dark setae. Pedicel and scape brown. Bases of antennal setae marked with a black spot. Thorax. All uniformly dark brown with mediotergite lighter. Scutum with long dark setae laterally and in dorsocentral rows. Scutellum with a row of subapical setae. Thoracic pleura and mediotergite bare. Legs. Coxae dark brown, the rest of legs light brown. Legs with dense microtrichia. A row of sparse black posterior setae running nearly full length of hind tibia. Tibial spurs 1:2:2. Wing hyaline and darkened, with macrotrichia on the membrane, but mostly concentrated near the wing tip and front margin. C ending about one-fourth the distance between R 4+5 and M 1 . Sc short, ending free, followed by long, faint, fold line, ending free near level of base of Rs. R 2+3 long, base basal to level of medial fork. R-m present but short. Stem of M weak. Anal vein long, setose, reaching wing margin. Abdomen. Mostly dark brown, with yellow thin posterior bands on tergites 2-4. Terminalia ( Figure 11C-E). Tergite nine short, subrectangular. Cerci twice as long as T9, flap-like. Gonocoxites fused ventrally, with posterior margin developed into a distinct median lobe. Gonostylus elongate, narrow, 5 times as long as broad, apically rounded, posterior part of its inner edge lined by numerous closely set short dark setae. Female. Similar to male in most aspects.

Family Keroplatidae
This is a relatively large and diverse family of Sciaroidea, currently comprising more than 1000 species in almost 100 genera and 6 subfamilies, including the subfamily Lygistorrhininae, previously considered as a separate family [3,11]. Oriental species of Keroplatidae were recently studied mostly by L. Papp and J. Ševčík (e.g., [26][27][28]). Several new extant species are described below.

Genus Chetoneura Colless, 1962
A small and peculiar genus of uncertain phylogenetic position [3], with 3 species currently described, all from the Oriental region [29]. An additional new species is described below.

Genus Euceroplatus Edwards, 1929
A small genus, with 9 described species from the Oriental or Australasian regions [29]. All these species have a species-specific color pattern on wings. An additional new  Table S1.
Etymology. This new species is named after Dr. David Kaspřák, a former doctoral student of the first author of this paper. He participated at the field research in Brunei and collected the type specimens of this species.
Diagnosis. This species is most similar to the type species of the genus, Chetoneura cavernae Colless, 1962, sharing principally the same wing venation with very short r-m fusion, and also similar structure of the male terminalia, with an apical tooth on the apex of gonostylus. The other two species of Chetoneura Colless, 1962 (=Bisubcosta Papp, 2006) have substantially longer r-m fusion [29]. Chetoneura davidi sp. nov. differs from Ch. cavernae mainly in the overall body coloration (thorax, coxae and abdomen partly yellowish and knob of haltere dark), costa less produced beyond the tip of R 5 , and relatively narrow gonostylus.
Description. Male. Wing length 4.6 mm (holotype). Head. Compound eyes relatively broad, covering most of the head in lateral view. Two ocelli (paratype, ocelli absent in holotype). Face broad (about as high as broad), brown, setose in its lower half, weakly sclerotized. Clypeus setose. Mouthparts reduced. Maxillary palpus consists of a small yellowish palpifer and an oval dark palpomere. Antenna long, about 1.5 times as long as the head and thorax together, with 14 flagellomeres. Flagellum laterally flattened, flagellomeres slightly prolonged both anteriorly and posteriorly. All flagellomeres dark brown. Scape and pedicel dark brown, slightly shorter than wide. Scutum yellowish, with lateral margins and two submedian longitudinal stripes dark (V-shaped, connecting posteriorly). Scutellum dark brown, medially darker, with subapical transverse row of short black setae. Mediotergite brown, medially setose, posteriorly only slightly protruding. Subscutellar membranous area very thin and indistinct, transverse, not tapering posteriorly. Lateral sclerites yellowish, only anepisternum dark. Laterotergite bare. Antepronotum and proepisternum dark and setose. Anterior spiracle and membranous area around it without setae. Anepisternum setose in its upper half, the other lateral sclerites bare. Haltere with the knob dark brown and stem lighter. Wing hyaline, without markings. Sc relatively long, reaching beyond r-m fusion. Vein C produced beyond R 5 to about one third of the distance between the tips of R 5 and M 1 . R 2+3 absent. M 2 reaching wing margin. CuA downcurved in the middle but almost straight towards the tip. A 1 short, not reaching wing margin. Costa, R 1 and R 5 covered with setae. Legs mostly yellowish brown, with coxae lighter but apically darker. Femora all dark. Tibiae brown. All tibiae with trichia arranged in dense longitudinal rows, without strong bristles. Fore tibia without distinct apical spur. Only one spur present on both mid and hind tibia. Spur on hind tibia rather long, about four times as long as maximum (apical) tibial diameter. A distinct transverse comb of closely set posterior setulae present apically on each tibia. Abdomen relatively long, bicolored, with segments 1-5 mostly yellowish, with dark posterior bands. Segments 6-9 all dark. Terminalia ( Figure 13A-C) dark brown. Tergite 9 slightly longer than broad. Gonocoxites broadly fused ventrobasally. Gonostylus shorter than gonocoxite, relatively narrow, about twice as long as wide, with a distinct apical tooth.
Discussion. The absence of ocelli in the holotype is noteworthy (in the paratype male two ocelli are present), and undoubtedly represents an individual aberration, rather than a useful taxonomic character. Both the holotype and paratype have identical COI barcode sequences.

Genus Euceroplatus Edwards, 1929
A small genus, with 9 described species from the Oriental or Australasian regions [29]. All these species have a species-specific color pattern on wings. An additional new species is described here. This species was included in the molecular analysis by Mantič et al. [3], under the name Euceroplatus sp. 1, and proved to be closely related to the more typical species of the genus, though undescribed, referred to as Euceroplatus sp. 2.
Euceroplatus mantici sp. nov. (Figures 3D and 13D-F DNA sequences. DNA sequence (COI barcode region) taken from the holotype (specimen No. JSBA24) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. This distinct new species is named after Dr. Michal Mantič, a former doctoral student of the first author of this paper, who collected the holotype. He participated also at the field trip to Brunei, where some other species included in this paper were collected.
Diagnosis. This species is rather unique and unmistakable due to its robust habitus, resembling rather some species of Keroplatus Bosc, 1792, than those of Euceroplatus. Further diagnostic characters are on the wing (central spot and subapical dark band), and a relatively broad gonostylus, placed rather dorsally than posteriorly on the gonocoxite, without an apical tooth or long setae.
Description. Male. Body robust, mostly yellowish brown. Wing length 5.0 mm. Head. Mostly brown, with dark short trichia beyond the eyes and on vertex. Three ocelli, the median one smaller, the distance between the eye margin and lateral ocellus is about the diameter of the latter. Ocelli placed on a dark triangle, connecting the eyes and the posterior margin of the head. Face narrow (three times as high as broad), yellowish, bare, weakly sclerotized and in its upper half medially divided by a dark sagittal furrow. Clypeus small and indistinct. Mouthparts reduced. Maxillary palpus consists of a small palpifer and a larger oval yellowish palpomere. Antenna relatively short, about 2.2 times as long as the head, with 14 flagellomeres. Flagellum laterally strongly flattened. All flagellomeres dark brown. Both F11 and F14 partly lighter (less than half of the flagellomere). Scape and pedicel dark brown, each of them twice as wide as long. Thorax. Scutum weakly arched, evenly covered with short setae and with longer setae along lateral margins, mostly yellowish brown, with dark posterolateral corners and two thin dark submedian longitudinal stripes (V-shaped, connecting posteriorly). Scutellum yellowish brown, dorsally densely covered with short black setae, without long apical bristles. Mediotergite yellowish, laterally brown, bare, posteriorly only slightly protruding. Subscutellar membranous area almost indistinct, reduced to a narrow transverse band. Laterotergite bare, yellowish, with darker upper and lower parts. Antepronotum and proepisternum densely setose. Anterior spiracle and membranous area around it without setae. Anepisternum bare, yellowish, with anterior third dark. Prosternum densely setose. Haltere bicoloured, with the stem lighter and the knob laterally dark. Wing ( Figure 3D) hyaline, with a large central spot and a broad subapical band. Sc rather long, setose, reaching beyond the base of r-m fusion. Vein C produced beyond R 5 to slightly more than a quarter of the distance between the tips of R 5 and M 1 . R 2+3 ending in C, almost touching the apex of R 1 . All median branches shortened, not reaching wing margin. CuA almost straight, not distinctly downcurved. A 1 strong, ending just before the wing margin. Costa, Sc, r-m fusion, R 1 and R 5 covered with strong setae. Legs mostly yellowish brown, tibiae and tarsi slightly lighter. Coxae mostly yellowish, darkened at apex, densely covered with dark setae along their anterolateral (C1, C2) or posterolateral (C3) surface. Femora mostly yellowish brown, evenly covered with short dark setulae. Tibiae light brown, darkened at apical ends. All tibiae with trichia arranged in dense longitudinal rows, with several scattered stronger setae. The apex of fore tibia without any distinct tibial organ. Fore tibia with one apical spur, slightly longer than maximum tibial diameter. Two spurs present on both mid and hind tibia, the posteroventral spurs about twice as long as the anteroventral ones. A distinct transverse comb of closely set posterior setulae apically on mid and hind tibia. Claws relatively large, simple, with short dense setulae basally. Abdomen bicolored, mostly ochreous, with tergites 5-7 darkened. Terminalia ( Figure 13D-F) ochreous, posteriorly darker. Tergite 9 subtriangular, slightly longer than broad. Gonocoxites fused ventrally, with a distinct medioventral lobe, covered with short black setae. Gonostylus less than half the length of gonocoxite, subrectangular to oval in shape, dorsally with a patch of short black setae.

Genus Platyceridion Tollet, 1955
Only two species of Platyceridion have been described up to the present, both from Sri Lanka, and they are known to have mycmecophilous larvae [30]. An additional species is described here form the Hainan Island, confirming a broader distributional pattern of the genus and possible association with islands. The biology of the new species remains unknown, although myrmecophily cannot be excluded due to common occurrence of an unidentified species of ants at the type locality.
Platyceridion yunfui sp. nov. (Figures 3E and 13G,H). DNA sequence. DNA sequence (COI barcode region) taken from the holotype (No. JSK81A) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. This species is named after Dr. Yunfu Chen, a former student at the Sun Yat-sen University in Guangzhou, China. He participated at the field trip to Hainan Island, where this species was collected.
Diagnosis. Platyceridion yunfui sp. nov. is most similar to P. talaroceroides (Senior-White, 1921), known from Sri Lanka [30], mainly due to the same coloration of the abdomen but differs in the structure of flagellum and in minor details on the male terminalia. The new species possesses long projections on flagellomeres 1 to 13 (1 to 12 in P. talaroceroides), its tergite 9 is somewhat broader and cerci longer than half of the length of T9. In addition, the gonostylus appears longer and less pointed apically than in P. talaroceroides. P. edax Chandler and Matile differs in the entirely yellow tergites 1-5.
Description. Male. Wing length 3.2 mm (holotype). Head yellowish brown, with dark setae posteriorly. Three dark ocelli, closely set to each other, the median one much smaller, the distance between the eye margin and lateral ocellus is about 1.5 times the diameter of the latter. Face twice as broad as high, yellowish, bare. Clypeus circular, covered with dark setae. Maxillary palpus brownish, consists of a small palpifer and three short palpomeres. Basal palpomere with a distinct sensory pit on its upper surface. Antenna about as long as thorax, strongly pectinate, with 14 flagellomeres. Flagellomeres with long anterior projections, almost as long as flagellum. F1 basally yellowish, the rest of flagellum brown. Both scape and pedicel yellowish, shorter than wide, with a ring of short dark setae. Thorax. Mostly brownish yellow, with scutellum and mediotergite dark. Scutum weakly arched, densely covered with dark setae. Scutellum dark brown, with short setae dorsally and a row of longer black setae subapically. Mediotergite brown, basally lighter, bare, posteriorly sharply protruding. Subscutellar membranous area indistinct. Lateral sclerites mostly yellowish. Laterotergite brownish, covered with long dark setae. Antepronotum and proepisternum setose. Anterior spiracle and membranous area around it with several short setae. Anepisternum with a patch of setae along its upper margin, the other lateral sclerites bare. Haltere slightly longer than the first abdominal tergite, with knob dark brown and stem lighter. Wing ( Figure 3E) hyaline, broadly darkened along distal and posterior margins and in central parts of the wing. Sc short, ending in C. Vein C produced beyond R 5 to about one third of the distance between the tips of R 5 and M1. R 2+3 short, ending in C. M 2 distinctly shortened, not reaching wing margin. CuA2 straight. A1 strong, reaching to wing margin. Costa, R 1 and R 5 covered with setae. Legs mostly yellowish, densely covered with dark trichia. Coxae and femora all yellowish. Tibiae light brown. All tibiae with trichia arranged in dense longitudinal rows. Fore tibia with one apical spur, two spurs present on both mid and hind tibia. The posteroventral spur on hind tibia about five times as long as the anteroventral one. A distinct transverse comb of closely set posterior setulae present on mid and hind tibia apically. Abdomen bicolored, basally yellowish brown, apically dark brown. Tergites 2-5 yellowish, with proximal half dark. Terminalia ( Figure 13G,H) dark brown. Tergite 9 pear-shaped, basally broader, slightly longer than broad. Cerci long, about two thirds of the length of T9. Gonocoxites fused ventrobasally. Gonostylus about as long as gonocoxite, tapering.
Female. Similar to male, except for the antennae and wing markings. Flagellar projections shorter, at most half as long as the length of flagellum ( Figure 3E). Wing markings more demarcated, with a distinct spot behind R 2+3 , behind r-m fusion and along Cu1, while the membrane around branches of M almost clear.
Discussion. As noted above, Platyceridion yunfui sp. nov. is very similar to P. talaroceroides, and the identity of both the species should be confirmed in the future using molecular methods.

Genus Setostylus Matile, 1990
A widespread genus, with 9 species currently described from the Oriental and Neotropical regions [31]. An additional new species is described below, representing the first record of the genus from Taiwan.  Table S1.
Etymology. This species is named after Fang-Shuo Hu, a Taiwanese coleopterist and student at the National Chung Hsing University in Taichung. He participated at the field trip to FuShan Botanical gardens, where the type specimens of this new species were collected.
Diagnosis. This species resembles Setostylus chinensis Cao, Evenhuis and Zhou, 2007, described from mainland China [31], mainly in the extensively marked wings, but differs in the shape of gonostylus (basally broader in S. fangshuoi sp. nov.) and tergite 9 (less triangular in S. fangshuoi sp. nov.).
Description. Male. Body slender, brightly colored ( Figure 15A). Wing length 2.8 mm. Head mostly brown. Compound eyes covering approximately half of the head in lateral view. Three ocelli, the median one smaller, the distance between the eye margin and lateral ocellus is about the diameter of the latter. Ocelli placed on a dark, heart-shaped tubercle. Face about as high as broad, brown, bare, weakly sclerotized and in its upper half medially divided by a dark sagittal furrow. Clypeus small and haired. Mouthparts reduced. Maxillary palpus consists of a palpifer and one palpomere, both of about the same length. Antenna relatively long, about 1.2 times as long as the head and thorax together, with 14 flagellomeres, all dark brown. Flagellum laterally strongly flattened. Flagellomeres 1-13 S-shaped, F14 subtriangular. Scape and pedicel dark brown, each of them twice as wide as long. Thorax. Scutum weakly arched, evenly covered with short setae, mostly yellowish, with two dark longitudinal stripes. Scutellum dark brown, with a subapical transverse row of short black setae, without long apical bristles. Mediotergite mostly brown, bare, posteriorly only slightly protruding. Subscutellar membranous area small and indistinct. Laterotergite bare, yellowish, with darker lower margin. Antepronotum and proepisternum setose. Anterior spiracle and membranous area around it without setae. Anepisternum setose in its uppermost part, the other lateral sclerites bare. Prosternum with sparse setae in its upper part. Haltere dark brown, basally lighter, slightly longer than the first abdominal tergite. Wing relatively broad, hyaline, extensively marked. Sc rather long, reaching to the distal end of r-m fusion. Vein C produced beyond R5 to about 3/5 of the distance between the tips of R 5 and M 1 . R 2+3 ending in C, almost touching the apex of R 1 . M 2 shortened, not reaching wing margin. CuP downcurved towards the tip. A1 strong, ending just before the wing margin. Costa, R 1 and R 5 covered with setae. Legs. Coxa 2 and 3 mostly dark, coxa 1 lighter. Femora mostly yellowish, F2 basally darkened, F3 dark at the apical third and basally. All tibiae with trichia arranged in dense longitudinal rows, without stronger setae. The apex of fore tibia without a tibial organ. Fore tibia with one apical spur, almost twice as long as maximum tibial diameter. Two spurs present on both mid and hind tibia, the posteroventral spur on T2 about twice as long as the anteroventral one, T3 with spurs subequal in length. A distinct transverse comb of closely set posterior setulae apically on mid and hind tibia. Abdomen relatively long, mostly dark brown, tergites 2-4 basally yellowish. Terminalia ( Figure 14A-C) with tergite 9 longitudinal, posteriorly rounded, not distinctly triangular. Gonocoxites fused ventrally, with short strong setae on the posterior margin, concentrated on two submedian tubercles. Gonostylus about as long as gonocoxite, broad in basal half, distally narrow, bearing a long apical seta.

Genus Terocelion Ševčík, 2012
A recently described genus, similar to Euceroplatus, with 2 species currently described from Brunei and Thailand [28]. An additional new species is described below, representing the first record of the genus from Taiwan.
Terocelion adami sp. nov. (Figures 3F and 14D-F DNA sequences. DNA sequence (COI barcode region) taken from the holotype (No. JSTW31) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. This beautiful species is named after Adam Ševčík, the son of the first author.
Diagnosis. This species is most similar to Terocelion melanoleucum Ševčík, 2012, differing mainly in details of body coloration and the shape of gonostylus, which is distinctly shorter in the new species than in T. melanoleucum. The type species of the genus, Terocelion terezae Ševčík, 2012, is distinct with its strongly pectinate antennae [28].
Description. Male. Wing length 5.6 mm (holotype). Head. Compound eyes about 2.3 times as high as broad in lateral view, distinctly emarginated above the bases of antennae. Three ocelli, the median one smaller, the distance between the eye margin and lateral ocellus is less than the diameter of the latter. Ocelli placed on a dark tubercle, medially divided by a distinct frontal furrow. Face narrow (three times as high as broad), light brown, bare, weakly sclerotized and in its upper half medially divided by a dark sagittal furrow. Clypeus small and indistinct. Mouthparts reduced. Maxillary palpus consists of a small palpifer and a larger oval yellowish palpomere. Antenna as long as the head and thorax together, with 14 flagellomeres. Flagellum laterally flattened, flagellomeres 2 to 13 prolonged both anteriorly and posteriorly. F1 to F11 plus F14 dark brown, F12 and F13 white. Both F11 and F14 partly lighter (less than half of the flagellomere). Scape and pedicel dark brown, slightly shorter than wide, with dark short setae. Scutum weakly arched, evenly covered with short setae, laterally and posteriorly with longer setae, yellowish brown with lateral margins and two submedian longitudinal stripes dark (V-shaped, connecting posteriorly). Scutellum light brown, medially darker, with subapical transverse row of short black setae. Mediotergite brown, proximally lighter, bare, posteriorly distinctly protruding. Subscutellar membranous area relatively small, subtriangular, transverse, not tapering posteriorly. Lateral sclerites bicoloured, light and dark brown ( Figure 3F). Laterotergite bare, with the upper half dark and the lower one light. Antepronotum and proepisternum setose. Anterior spiracle and membranous area around it without setae. Anepisternum and the other lateral sclerites bare. Prosternum without setae. Haltere slightly longer than the first abdominal tergite, with the knob dark brown and stem lighter. Wing ( Figure 3F) hyaline, distinctly marked. Sc short, reaching to the base of r-m fusion. Vein C produced beyond R 5 to slightly less than half the distance between the tips of R 5 and M 1 . R 2+3 ending in C. M 2 shortened, not reaching wing margin. CuP downcurved towards the tip. A 1 strong, ending just before the wing margin. Costa, R 1 and R 5 covered with setae. Legs mostly yellowish white, tibiae and tarsi slightly lighter. Coxa 1 white, coxa 2 dark on apical 1 4 , costa 3 dark on apical 1/3. Femora yellowish white, femur 2 dark basally, femur dark on basal 1/3. Tibiae light brown, darkened at apical ends. All tibiae with trichia arranged in dense longitudinal rows, without strong bristles. The apex of fore tibia without any tibial organ. Fore tibia with one apical spur, slightly longer than maximum tibial diameter. Two spurs present on both mid and hind tibia, the posteroventral spurs about twice as long as the anteroventral ones. A distinct transverse comb of closely set posterior setulae apically on mid and hind tibia. Abdomen relatively long, bicolored, mostly dark brown, tergites 2-5 mostly yellowish, with dark dorsal triangular markings tapering proximally. Sternites 2-5 yellowish with dark apical margins. Terminalia ( Figure 14D-F) dark brown, basally lighter. Tergite 9 subtriangular, slightly longer than broad. Gonocoxites fused only ventrobasally, with stronger setae along their posterior margin. Gonostylus distinctly shorter than gonocoxite, almost as long as wide, subtriangular to oval in shape, without distinct apical tooth, dorsally with a longitudinal submedial furrow.

Family Mycetophilidae
This is one of the largest families of Sciaroidea, comprising more than 4500 described extant species in more than 230 genera [32]. The concept and relationships among the subfamilies and particular genera vary greatly among authors. Oriental species of Mycetophilidae were studied by many authors in the past, as well as recently, e.g., References [4,5,33,34]. Two new extant species are described below.

Genus Hadroneura Lundström, 1906
A small genus of Gnoristinae, with 8 species currently described from the Holarctic region. An additional new species is described below, representing the first record of the genus from Taiwan. This genus is very similar to Dziedzickia Johannsen, 1909, if not a subgroup of it, depending on the generic concept, which varies among authors. In any case, Hadroneura is an older available name, which would have priority over Dziedzickia. As discussed already by Ševčík et al. [4], Dziedzickia is a very heterogeneous genus, including several distinct species groups and many undescribed species worldwide, and, thus, needs detailed revision.
Hadroneura martini sp. nov. (Figures 1B, 15B and 16A DNA sequences. DNA sequence (COI barcode region) taken from the holotype (No. JSTW25) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. This species is named after Dr. Martin Fikáček, a coleopterist from the National Museum in Prague. He participated at the field trip to Renai (Taiwan) where this new species was collected.
Diagnosis. Among the species of Hadroneura, the new species is quite distinctive due to its yellow flagellum and head without a proboscis.   Description. Male. Wing length 3.8 mm. Body mostly dark brown, except for the yellow antennal flagellum and partly yellow legs ( Figure 15B). Two ocelli, near the eye margin, but not touching it. Distinct frontal suture, reaching from the antennae to the occiput. Antenna with 14 yellow cylindrical flagellomeres. Scape and pedicel yellowish brown. Mouthparts normal, not distinctly reduced or prolonged. Palpus brown, with four visible palpomeres, the apical one twice as long as the previous one. Scutum with acrostichal, dorsocentral and lateral setae; areas between them bare. Scutellum dark, covered with short setulae and several longer bristles. Laterotergite with long setae, mediotergite bare. Wing ( Figure 1B) hyaline, light brown, unmarked, but with veins Rs and M 2+3 darkened, membrane without macrotrichia. Costa only shortly produced beyond R 5 . Sc long, distally setose, ending in R 1 between base of Rs and R 2+3 . R-m about as long as Rs. M 4 long, starting close to wing base. Anal vein short and bare. Haltere yellow, with a dark knob. Coxae and femora dark brown, tibiae yellow, except for dark brown hind tibia. Tibiae with dense, irregularly arranged, trichia. Mid and hind tibia with several anterodorsal and posterodorsal setae. Fore tibia with a distinct tibial organ. Two yellow spurs on mid and hind tibia, front tibial spur brown. Abdomen all dark brown. Terminalia ( Figure 16A,B). Tergite 9 short, transverse, densely covered with long setae, cercus about as long as tergite 9, with a subapical row of long setae. Gonostylus narrow, tapering, shorter than gonocoxite.

Genus Terocelion Ševčík, 2012
A recently described genus, similar to Euceroplatus, with 2 species currently described from Brunei and Thailand [28]. An additional new species is described below, representing the first record of the genus from Taiwan.
Terocelion adami sp. nov. (Figures 3F and 14D-F  We take the opportunity here to synonymize the genera Acomoptera, Drepanocercus and Loicia with Paratinia, the oldest available generic name in this group. Their close relationship and similarity are evident from the studies based on both molecular and morphological characters (e.g., References [32,[35][36][37]). Above other characters, these four former genera share principally the same wing venation and general outline of the male terminalia. The wing venation of Loicia is unique due to basal branching of CuA [37], but intraspecific variation of some wing characters was demonstrated within this group, e.g., in Drepanocercus; see Reference [38]. We take the opportunity here to synonymize the genera Acomoptera, Drepanocercus and Loicia with Paratinia, the oldest available generic name in this group. Their close relationship and similarity are evident from the studies based on both molecular and morphological characters (e.g., References [32,[35][36][37]). Above other characters, these four former genera share principally the same wing venation and general outline of the male terminalia. The wing venation of Loicia is unique due to basal branching of CuA [37], but intraspecific variation of some wing characters was demonstrated within this group, e.g., in Drepanocercus; see Reference [38].
Although several species groups (see Kerr [35]) may be recognized within such a broadly defined genus, they do not correspond to the genera as were defined up to the present. Species of Loicia and Paratinia share a distinct character state, setosity of the wing membrane (macrotrichia). However, this character state is known to be parallelly developed or absent even within a single genus of Sciaroidea, e.g., in Macrocera (Keroplatidae) or Trichosia (Sciaridae). Unfortunately, the setosity of wing membrane has been widely used as one of the key characters to separate the mycetophilid subfamilies Gnoristinae and Sciophilinae, leading to incorrect assignment of Paratinia to Sciophilinae in the past. The recent molecular study by Kaspřák et al. [32], however, clearly demonstrated that Paratinia, including Acomoptera and Loicia, represent a well-supported monophyletic group within Gnoristinae. Although several species groups (see Kerr [35]) may be recognized within such a broadly defined genus, they do not correspond to the genera as were defined up to the present. Species of Loicia and Paratinia share a distinct character state, setosity of the wing membrane (macrotrichia). However, this character state is known to be parallelly developed or absent even within a single genus of Sciaroidea, e.g., in Macrocera (Keroplatidae) or Trichosia (Sciaridae). Unfortunately, the setosity of wing membrane has been widely used as one of the key characters to separate the mycetophilid subfamilies Gnoristinae and Sciophilinae, leading to incorrect assignment of Paratinia to Sciophilinae in the past. The recent molecular study by Kaspřák et al. [32], however, clearly demonstrated that Paratinia, including Acomoptera and Loicia, represent a well-supported monophyletic group within Gnoristinae.

Sciaroidea Incertae Sedis
This is a group of some 20 genera of Sciaroidea, which have not yet been definitely assigned to a family. These taxa were traditionally treated as the Heterotricha Loew, 1850, group but, in recent years, have been referred to as Sciaroidea incertae sedis [2,[40][41][42]. Two new species from this enigmatic group are described below, one of them in a new fossil genus.   Table S1.
Etymology. The specific name refers to the distinct, fork-like structure of the medioventral process of the gonocoxites (hypandrial lobe).
Diagnosis. This new species clearly differs from Paratinia sciarina Mik, 1874 in the shape of gonostylus and medioventral process of gonocoxites (see Figure 17).
Description. Male. Wing length 5.4 mm (holotype). Entire body dark brown. Three ocelli, lateral ones almost touching the eye margin. Antenna dark brown, with 14 elongated flagellomeres. Palpus brown, with four visible palpomeres, the apical one twice as long as the previous one. Scutum with acrostichal, dorsocentral and lateral setae; areas between them bare. Scutellum dark, with several subapical bristles. Mediotergite and all lateral thoracic sclerites bare. Wing hyaline, unmarked, membrane with sparse macrotrichia only in distal half of the wing. Costa produced beyond R5 to about 1/3 of the distance between the tips of R5 and M1. Sc long, ending in C beyond the base of Rs. R-m almost twice as long as Rs. M4 joining Cu at the level of the base of r-m. Anal vein short, but strong and setose. Haltere yellowish brown. Legs yellowish brown, tarsi darker. Tibiae densely covered with short, irregularly arranged, trichia. Fore tibia without a tibial organ. First tarsomere in all legs prolonged, about as long as tibia. Tibial spurs yellow, 1:2:2. Abdomen all dark brown. Terminalia ( Figure 17A-C). Tergite 9 very short, about twice as broad as long, cerci oval, slightly longer than tergite 9, covered with setae. Gonocoxites fused, with a large medioventral sclerotized process, which is deeply forked, with branches apically pointed. Gonostylus twice as long as broad, shorter than gonocoxite, with two apical weakly sclerotized teeth.

Discussion.
There are several undescribed species of Paratinia, similar to P. furcata sp. nov., known from various European countries (e.g., Figure 25B in Søli [36]), pending a detailed revision of this group, which is beyond the scope of this paper. In any case, a careful comparison of the male terminalia, together with DNA sequence data, is necessary to clarify the identity of all the species in this genus. There are also several undescribed Oriental species of Paratinia known to us (from Brunei, Taiwan, Thailand), but they will be described in a separate paper.
Diagnosis. This species is recognizable from the other members of the Heterotricha group (=Sciaroidea incertae sedis) by the short Sc, ending free, long C, the absence of macrotrichia on wing membrane, veins r-m, m-m and m-cu in one line, and the simple structure of male terminalia.
Description. Male. Wing length approximately 1.7 mm (holotype). Head with relatively large compound eyes, which are emarginated near antennal base. Palpi with three visible segments. Antennae relatively long, as long as the wing, with 14 flagellomeres, F5-F14 about 8 times as long as broad. Wing relatively narrow, with ratio of length to width about 3.1. Macrotrichia on wing membrane absent. Sc ending in C before the level of Rs. C distinctly produced, reaching almost to the apex of M 1 . Vein R 2+3 absent. Veins r-m, m-m and m-cu in one nearly horizontal line. Stem of M-fork long, slightly longer than M 1 . CuA strong and downcurved. Both CuP and anal veins not traceable. Legs covered with trichia and several sparse posterior setae on mid and hind tibia. Tibial spurs 1:2:2. Terminalia ( Figure 10B) with tergite 9 short, about twice as broad as long. Cerci short but longer than T9. Gonostylus simple, unbranched, as long as gonocoxites, narrow, strongly sclerotized in the posterior half and apically rounded.
Discussion. The phylogenetic position and interrelationships of various genera of the Sciaroidea incertae sedis are a real puzzle, which is beyond the scope of this paper, but preliminary molecular data suggest that these genera do not constitute a monophyletic group [2,32]. The family placement of these genera is also obscure, although there are some indications that they could belong to the Mesozoic family Antefungivoridae [41]. DNA sequences. DNA sequence (COI) taken from the holotype (No. JSBA25A) is deposited in GenBank. Its Accession number is provided in Table S1.
Etymology. This species is named after Mr. Tomáš Sikora (University of Ostrava, Czech Republic), a student of lower gall midges, who collected the type specimen.
Diagnosis. Nepaletricha sikorai sp. nov. is similar to N. dembickyi Hippa and Ševčík, 2014 and N. montana Hippa and Ševčík, 2014. All three differ from the other Nepaletricha by having the gonocoxites posterolaterally divided into posteriorly directed large lobes, longer than the undivided anterior part. In N. dembickyi and N. montana, there is one more ventral and one more dorsal lobe, while, in N. sikorai sp. nov., there are two more dorsal ones, both equal in size. All the three species are different in many details in their terminalia ( Figures 12G,H and 2A,B in Hippa and Ševčík [41], Figure 4A-D in Hippa et al. [43]).
Supplementary Materials: The following are available online at https://www.mdpi.com/article/ 10.3390/insects13010019/s1, Table S1: List of specimens used for DNA extraction, with GenBank accession numbers.