Synopsis of the genus Ulomorpha Osten Sacken, 1869 (Diptera, Limoniidae) in Japan

Abstract Japanese species of the genus Ulomorpha Osten Sacken, 1869 are revised and U. amamiana Kato & Kolcsár, sp. nov. and U. longipenis Kato & Kolcsár, sp. nov. are described. A key to the four Japanese species of the genus is provided, with images of habitus and wings, and drawings of their male terminalia. Ulomorpha amamiana Kato & Kolcsár, sp. nov. is the first representative of the genus discovered from the Oriental region.


Introduction
Ulomorpha Osten Sacken, 1869 is a small genus of the subfamily Limnophilinae and so far includes two Palaearctic and eight Nearctic species (Oosterbroek 2020). The adults are characterized by having conspicuous macrotrichiae on wing cells and cell R 3 sessile to subsessile. A similar condition is present in the limnophiline genera Adelpho-myia Bergroth, 1891, Paradelphomyia Alexander, 1936, andLimnophila (Lasiomastix) Osten Sacken, 1860 but only in Ulomorpha are macrotrichiae proximal to the cord present. Morphological analyses of the characters of immature stages demonstrate that Ulomorpha is closely related to Pilaria Sintenis, 1889 (Oosterbroek and Theowald 1991). Cladistic analysis of the adult morphological characters recovered a close relationship of Ulomorpha with Pseudolimnophila Alexander, 1919, Pilaria, andHexatoma Latreille, 1809 owing to the bifid interbase in males (Ribeiro 2008).
Immature stages of U. pilosella (Osten Sacken, 1860) were described by Alexander (1920a) and were reported from soil rich in organic matter in shaded woods (Alexander and McAtee 1920), but the biology of the genus is otherwise poorly known.
Two species of the genus have been recorded from Japan, U. nigricolor Alexander, 1924 (Honshu, Shikoku, and Kyushu islands) and U. polytricha Alexander, 1930 (Yakushima Island) (Nakamura 2014;Oosterbroek 2020). In this study, the Japanese species of the genus are revised, and two new species are described, with additional faunistic records including the first representative of the genus from the Oriental region. Images of wings and habitus, drawings of male terminalia, and a key to the Japanese species are provided.

Materials and methods
The specimens were collected by insect nets by D. Kato and L.-P. Kolcsár and either preserved in 90% ethanol or pinned. Overall descriptions of the species were based on the observations made through a Leica MZ7.5 stereomicroscope. Male terminalia of pinned specimens were heated in a solution of 10% KOH for several minutes, then rinsed in a solution of 70% ethanol with 3% acetic acid for neutralization and transferred to glycerol for examination and drawing. The treated genitalia were preserved in genitalia tubes filled with glycerol and the tubes were pinned below the body remains. Drawings were made using the stereomicroscope equipped with a grid eyepiece micrometer. Habitus and wings were photographed with an Olympus OM-D E-M5 Mark II using a M. Zuiko Digital ED 60 mm F2.8 macro lens. Wing venation terminology follows the traditional system, based on McAlpine (1981) and Merz and Haenni (2000), with a modifications from Starý (2008); CuA is referred to here as Cu (Fig. 1C). General distributions of species are from the Catalogue of the Craneflies of the World (Oosterbroek 2020 General description of Japanese species of Ulomorpha Osten Sacken, 1869. General coloration shiny black, mainly yellow on legs, body clothed with relatively long setae. Head with eye dichoptic, separated by about twice width of scape on dorsal part and about 1.5 times on ventral part; rostrum 2/3-3/4 length of scape; antenna 16segmented, 3-4 times as long as head; scape cylindrical, about twice length of pedicel and as wide as pedicel; pedicel globular; flagellum with verticils, longer on middle segments, at most 2.5 times as long as each segment, shortest on apical segment, shorter than apical segment; basal flagellomeres (Figs 1B, 4B) long-oval with pubescences ventrally, as long as 1/2-1 width of each segment; distal flagellomeres long and cylindrical; palpus 5-segmented, shortest on basal segment and longest on apical segment.
Thorax with prescutal pit roundish; tuberculate pit situated near anterior margin on prescutum; meron small, largely membranous on posterior part, separating mid and hind coxae by about 1/2 width of coxa; wing (Figs 1C, 2B, 3B, C, 4C) covered with macrotrichiae except basal part; Sc end at level of distal 1/3 to tip of Rs; crossvein sc-r near tip of Sc; MA present; Rs origin near middle between MA and distal end of Rs; crossvein R 2 indistinct, situated at basal 1/2-1/4 of R 3 ; R 3+4 very short, often absent; M 1+2 not forked (forked in some Nearctic species); cell d closed; crossvein m-cu situated near middle of cell d; Cu curved posteriorly near wing margin; halter about half length of hind coxa; legs with tibial spurs 1 + 2 + 2; tarsomeres 1 to 3 each with 1 tarsal spur; claw about half as long as tarsomere 5, covered with small, hair-like setae on basal half, ventral margin smooth, without teeth; arolium present.
Ovipositor (Fig. 3I) long, more than 1/3 as long as abdomen; cercus more than 1.5 times as long as tergite 10, weakly upcurved on distal part; hypogynial valve more than 1.5 times as long as sternite 8, almost straight, tip ending at near level of middle of cercus. Wing with stigma distinctly dark and fork of Rs to crossvein r-m weakly dark (Fig. 2B); aedeagus with rod-shaped part more than three times as long as wide (Fig. 2F)  Male flagellum oval on basal 4 segments, with pubescence on basal 6-7 segments ventrally (Fig. 1B); medial lobe of interbase medial to base of outer lobe about 1.5 times as long as wide (Fig. 1H) (BLKU).
Diagnosis. Body blackish. Vertex and scutum sparsely pruinose. Flagellomeres oval to bacilliform on basal 4 segments; ventral sides with pubescences on basal 6-7 segments. Wing brownish tinged, unpatterned; stigma sometimes indistinctly darker. Halter yellow. Interbase with outer lobe shorter than medial lobe in dorsal view; medial lobe medial to base of outer lobe about 1.5 times as long as wide. Aedeagus with rod-shaped distal part, twice as long as wide and almost straight.
Description. Male. Body length 5.6-8.0 mm, wing length 5.8-7.9 mm. Head: subnitidous black, sparsely dusted with gray pruinosity; vertex with brighter gray pruinosity at anterior end. Rostrum and mouthparts brown to dark brown. Antenna brown to dark brown; scape and pedicel sometimes slightly darker; basal 4 flagellomeres oval to bacilliform; basal 6-7 segments covered with pubescences ventrally (Fig. 1B). Thorax: subnitidous dark brown to black, sparsely dusted with brownish pruinosity; postpronotum yellowish or brownish. Wing (Fig. 1C) tinged with brown; basal region yellowish; stigma absent or indistinctly darker; veins dark brown, yellowish on basal part of wing; barely dark seam sometimes present on fork of Rs to crossvein r-m. Halter yellow. Legs mainly yellow to dusky yellow; fore coxa sometimes weakly dark on basal part; femora narrowly dark at tips; dark area on fore femur sometimes weak and occupying distal half; tibiae narrowly dark at tips; tarsi weakly dark from tip of tarsomere 1 to apical segment.
Abdomen: subnitidous dark brown to black, sparsely covered with brownish pruinosity.
Male terminalia (Fig. 1D-H): caudal margin of tergite 9 roundly produced at middle, with small U-shaped notch at center. Outer gonostylus in dorsal view ( Fig. 1E) with tip narrowed and curved anteriorly; concaved margin with indistinct teeth. Interbase with outer lobe shorter than medial lobe in dorsal view (Fig. 1F); outer lobe wide at base, inner basal end situated near middle of medial lobe (Fig. 1H); medial lobe strongly narrowed distally, distal part medial to base of outer lobe about 1.5 times as long as wide (Fig. 1H); aedeagus with rod-shaped distal part, twice as long as wide andalmost straight (Fig. 1F, G).
Etymology. The name of this species is derived from that of the type locality, Amami Island. The name is deemed to be a latinized adjective in nominative singular.
Biogeographic notes. The crane fly fauna of the Nansei Islands or Ryukyu Arc is poorly known, and the new species and new distribution records are recently reported (Kato 2020;Kolcsár et al. 2020, in press). The Amami Islands are in the northeastern part of the Oriental faunal realm. The hypothetical boundary between the Palearctic and Oriental (Indomalaya) realms, the Watase line or Tokara gap, is delimited between Yakushima/Tanegashima and Amami islands (Komaki and Igawa 2017). The Ryukyu Islands arc once formed a continental margin arc which connected to the eastern margin of the Asian continent and served as an important land bridge (Osozawa et al. 2012). The presence of Ulomorpha in the Amami Islands is not surprising, as the group occurs in Yakushima Island. However, U. amamiana Kato & Kolcsár, sp. nov. is the first representative of the genus in the Oriental faunal realm. Future phylogenetic analyses may help understanding of the biogeography of the group in the area.
Remarks. This species is similar to U. polytricha Alexander, 1930. See the key to the Japanese species above for differentiation and diagnostic characters.   lobe shorter than medial lobe in dorsal view; medial lobe medial to base of outer lobe about 2.3 times as long as wide. Aedeagus with rod-shaped distal part, 3.3-4.4 times as long as wide and almost straight.
Description. Male. Body length 7.2-11.0 mm, wing length 7.1-11.9 mm. Head: subnitidous black, sparsely dusted with gray pruinosity; vertex with brighter gray pruinosity at anterior end; anterior part of vertex sometimes largely shiny except anterior end or with shiny and small, longitudinally long bacilliform area at middle posterior to anterior brighter area. Rostrum and mouthparts dark brown. Antenna with scape and pedicel dark brown; flagellum dusky yellow to brown; basal 2-3 flagellomeres oval, covered with pubescences ventrally.
Thorax: subnitidous black, sparsely dusted with brownish pruinosity, sometimes polished and pruinosity absent on prescutum and most of scutal lobe; postpronotum yellowish or brownish. Wing (Fig. 2B) tinged with brown; basal and costal regions proximal to cord yellowish; stigma oval, dark brown, with faint outline; veins dark brown, yellowish on Sc and basal part of wing; weakly dark seam on fork of Rs to crossvein r-m. Halter yellow to dusky yellow. Legs mainly yellow to dusky yellow; fore coxa dark on basal half, sometimes entirely so, mid and hind coxae sometimes narrowly dark at bases; femora narrowly dark at tips; dark area on fore femur often extending to near middle; tibiae narrowly dark at tips; tarsi weakly dark from tip of tarsomere 1 to apical segment.
Abdomen: subnitidous dark brown to black, sparsely covered with brownish pruinosity. Male terminalia (Fig. 2C-G): caudal margin of tergite 9 roundly produced at middle, with shallow U-shaped notch at center. Outer gonostylus in dorsal view ( Fig.  2D) with tip narrowed and curved anteriorly, concaved margin with distinct teeth. Interbase with outer lobe shorter than medial lobe in dorsal view (Fig. 2E); outer lobe wide at base, inner basal end situated near middle of medial lobe (Fig. 2G); medial lobe strongly narrowed distally, weakly sinuous, distal part medial to base of outer lobe about 2.3 times as long as wide (Fig. 2G). Aedeagus with rod-shaped distal part, 3.3-4.4 times as long as wide and almost straight (Fig. 2E, F), usually shorter in specimens from southern part of Japan.
Etymology. The specific epithet is from the Latin longus/longi (long) + penis (penis) and refers to the long aedeagus of this species compared to the other Japanese species of the genus. The name is an adjective in nominative singular.
Remarks. This species is similar to U. polytricha Alexander, 1930 but is differentiated from it by the following characters: wing with stigma distinctly dark, fork of Rs to crossvein r-m weakly darkened (Fig. 2B) (stigma indistinct in U. polytricha; Fig. 4C); aedeagus with rod-shaped part more than three times as long as wide (Fig. 2F) (twice as long as wide in in U. polytricha; Fig. 4G). This species also resembles a Nearctic species, U. nigronitida Alexander, 1920, according to the original description (Alexander 1920b), but is distinguished from it by the following characters: antenna pale on flagellum, yellow to brown (black throughout in U. nigronitida); coxae with distal parts yellowish (coxae brownish black, hind pair paler in U. nigronitida); halter entirely yellowish (knob dark brownish black in U. nigronitida).  Diagnosis. Body blackish. Vertex sparsely pruinose, anterior part largely polished. Flagellomeres oval on basal 2-4 segments; ventral sides with pubescences on basal 2-6 segments. Prescutum polished, with narrow longitudinal line of pruinosity at middle. Wing brownish tinged, with oval, dark-brown stigma and dark spot or seam each on Rs origin, anterior part of cord, crossvein m-cu, and outer end of cell d; dark spot at tip of A 2 sometimes present. Halter yellowish. Interbase with outer lobe as long as medial lobe in dorsal view; medial lobe medial to base of outer lobe about 3.5 times as long as wide. Aedeagus with rod-shaped distal part, twice as long as wide and weakly curved ventrally.
Thorax: subnitidous black, sparsely dusted with brownish pruinosity; polished and pruinosity absent on prescutum and most of scutal lobe; postpronotum sometimes yellowish; prescutum with narrow longitudinal line of pruinosity at middle in whole length, sometimes anterior part of this line indistinct. Wing (Fig. 3B, C) tinged with brown; basal and costal regions proximal to cord yellowish; stigma oval, dark brown, faint in outline; veins dark brown, yellowish on Sc and basal part of wing; dark, wide seam on fork of Rs to crossvein r-m; narrow, dark seam on each of crossvein m-cu and outer end of cell d, but one on latter sometimes indistinct; dark small spot at Rs origin and sometimes with additional one at tip of A 2 (Fig. 3C), this anal spot usually present in specimens from southern part of Japan. Halter yellow to pale yellow. Legs mainly yellow to dusky yellow; fore coxa dark on basal 1/2, sometimes entirely so; mid and hind coxae yellow to dark brown, sometimes dark at bases in case of yellowish coxae; femora narrowly dark at tips, dark area on fore femur sometimes occupying distal 1/3; tibiae narrowly dark at tips; tarsi weakly dark from tip of tarsomere 1 to apical segment.
Abdomen: subnitidous dark brown to black, sparsely covered with brownish pruinosity. Male terminalia (Fig. 3D-H): caudal margin of tergite 9 almost straight or weakly convex at middle, with shallow U-shaped notch at center. Outer gonostylus in dorsal view (Fig. 3E) relatively wide on distal part, tip narrowed and curved anteriorly, concaved margin with indistinct teeth. Interbase with outer lobe as long as medial lobe in dorsal view (Fig. 3F); outer lobe wide at base, inner basal end situated near middle of medial lobe (Fig.  3H); medial lobe strongly narrowed and rod-shaped on distal half, distal part medial to base of outer lobe about 3.5 times as long as wide (Fig. 3H); Aedeagus with rod-shaped distal part, twice as long as wide and tip weakly curved ventrally (Fig. 3G).
Remarks. This species is easily distinguished from the other species of the genus by the following combination of characters: thorax and abdomen excluding legs dark brown to black; wing with distinct dark areas each at origin of Rs, on fork of Rs to crossvein r-m, and outer end of cell d (Fig. 3B, C).  (BLKU).

Ulomorpha polytricha
Diagnosis. Body blackish. Vertex sparsely pruinose. Basal 2-3 flagellomeres oval, with pubescence ventrally. Prescutum sparsely pruinose. Wing brownish tinged, unpatterned except indistinctly darker stigma. Halter yellow. Interbase with outer lobe shorter than medial lobe in dorsal view, medial lobe medial to base of outer lobe more than twice as long as wide. Aedeagus with rod-shaped distal part, about 2.2 times as long as wide and almost straight.
Thorax: subnitidous dark brown to black, sparsely dusted with brownish pruinosity; postpronotum yellowish or brownish. Wing (Fig. 4C) tinged with brown;, basal region yellowish; stigma indistinctly darker; veins dark brown, yellowish on basal part of wing; barely dark seam sometimes present on fork of Rs to crossvein r-m. Halter yellow. Legs mainly yellow to dusky yellow; fore coxa dark on basal half; femora narrowly dark at tips of mid and hind pairs; fore femur dark on distal 2/3; tibiae narrowly dark at tips; tarsi weakly dark from tip of tarsomere 1 to apical segment.
Abdomen: subnitidous dark brown to black, sparsely covered with brownish pruinosity. Male terminalia (Fig. 4D-H): caudal margin of tergite 9 roundly produced at middle, with shallow U-shaped notch at center. Outer gonostylus in dorsal view with tip narrowed and strongly curved anteriorly, concaved margin with small teeth (Fig. 4E). Interbase with outer lobe shorter than medial lobe in dorsal view (Fig. 4F); outer lobe weakly wide at base, inner basal end at basal 1/3 of medial lobe (Fig. 4H); medial lobe gradually narrowed distally, distal part medial to base of outer lobe more than twice as long as wide (Fig. 4H). Aedeagus with rod-shaped distal part, about 2.2 times as long as wide and almost straight (Fig. 4G).