Tipula (Vestiplex) crane flies (Diptera, Tipulidae) of Korea

Abstract The Korean species of Tipula (Vestiplex) Bezzi, 1924 crane flies are taxonomically revised. Five species are recognized. Tipula (V.) coquillettiana Alexander, 1924, T. (V.) kuwayamai Alexander, 1921, T. (V.) tchukchi Alexander, 1934, and T. (V.) verecunda Alexander, 1924 are newly recorded from the Korean Peninsula, and T. (V.) serricauda Alexander, 1914 was previously recorded. The larva of T. (V.) serricauda is described and illustrated, and the larvae of the subgenus T. (Vestiplex) are divided into four groups based on spiracular lobe morphology. An identification key, redescriptions, and illustrations of Korean T. (Vestiplex) adults and grouping of known larvae are presented.


Introduction
Tipula Linnaeus, 1758 is the largest genus in the family Tipulidae with a worldwide distribution, and it is divided into 41 subgenera. The subgenus T. (Vestiplex) Bezzi, 1924 is a terrestrial group represented by 177 species and subspecies recorded from Holarctic and Oriental regions (Oosterbroek, 2019). The highest diversity of this  the terms ventral lobe and dorsal lobe of appendage of ninth sternite are adopted from Gelhaus (2005), the term gonocoxal fragment (= sclerites sp1 and sp2 (Neumann, 1958), = genital bridge (Dobrotworsky 1968)) for inner structure covered by ninth tergite is adopted from Brodo (2017). Descriptive terminology of larva generally follows that of Gelhaus (1986) and Neugart et al. (2009).
The overall world distribution of species is given according to Oosterbroek (2019).
The world fauna of the subgenus T. (Vestiplex) includes 177 recent species and subspecies, which are distributed throughout the Nearctic, Palaearctic, and Oriental regions (Oosterbroek 2019). The majority of the species are associated with mountain systems (Pyrenees, Alps, Caucasus, and Himalayas) where adults are commonly found at altitudes ranging from 700 to 2500 m and rarely up to 4500 m (Savchenko 1960).
The immature stages develop in terrestrial habitats such as the uppermost layer of soil under leaf or needle litter, or under mosses (Chiswell 1956;Rogers 1942;Theowald 1967;Teale and Gelhaus 1984;Lantsov 2003;Podeniene 2003). Larvae of T. (Vestiplex) are easily recognized because of a brown band separating the anus from the anal papillae.
The lobes surrounding spiracular field are subconical with the lateral lobe situated dorsolaterally. The sclerotization of the dorsal lobe varies depending on species, with some species bearing a sclerite only on the basal part of the posterior surface, while in other species the entire anterior and posterior surfaces are sclerotized. In this case the apex of the dorsal lobe is sclerotized, pointed, and directed anteriorly. The lateral lobe may possess a narrow and vertical sclerite, but it may be entirely absent in some species. The ventral lobe is the smallest and trianglar. It varies from extensively sclerotized to possessing only a small sclerite. Larvae have two pairs of short, blunt anal papillae. The length and macrosetal arrangement is consistent on the dorsum and tergum among all known species. Short microscopic hairs are arranged in transverse rows and cover most of the abdomen. Alexander, 1924 Tipula (Vestiplex) kuwayamai Alexander, 1921 Tipula (Vestiplex) serricauda Alexander, 1914 Tipula (Vestiplex)  Diagnosis. Tipula (V.) coquillettiana can be easily recognized by the ninth tergite, which forms a narrow, saucer-shaped plate, and the horn-shaped gonocoxite. The tip of the gonocoxite is bifurcate. The female of this species has a gray, elongated abdomen and greatly reduced wing. The cercus is straight with its tip narrowed and the ventral margin and apical part of the dorsal margin distinctly serrated. The hypovalva is in the shape of an elongated filament.
Head. Vertex and occiput gray with dark median line. Rostrum yellowish, thinly dusted with gray dorsally. Nasus distinct. Antenna 13-segmented, if bent backward extending beyond wing base. Scape and pedicel yellow; first flagellar segment basally yellow, distally brownish black; succeeding flagellar segments brownish black. Each flagellomere, except first, with basal enlargement and small incision. Apical flagellomere small, reduced. Verticils approximately as long as corresponding segments. Palpus with first segment yellowish, second brownish yellow, and other segment brownish black.
Thorax. Pronotum yellowish, thinly dusted with gray. Prescutum and presutural scutum gray; stripes bluish gray bordered by brown. Postsutural scutum, scutellum, and postnotum gray with bluish shade; all sclerites with dark, median line. Pleura brownish, dusted with gray. Coxa gray; trochanter yellowish; femur brownish yellow with tip broadly darkened; tibia brownish yellow; tarsal segments dark brown. Tarsal claw without tooth. Wing patterned with brown. Halter brownish yellow with brown knob.
Abdomen. Yellow. First abdominal segment dusted with gray. Abdominal segments 2 and 3 yellow, 4 and 5 brownish-yellow, and remaining segments dark brown. Lateral margin of tergites pale yellow. Dorsal median stripe pale, broadly interrupted.
Known distribution. Russia, Kazakhstan, and Japan (Oosterbroek 2019). Recorded here for the first time from North Korea. Alexander, 1921 Figs 16-29, 87 Tipula kuwayamai Alexander 1921: 130;1925: 93. Tipula (Vestiplex) kuwayamai : Alexander 1934: 405;1935: 118;Savchenko 1964: 179; Oosterbroek and Theowald 1992: 156. Diagnosis. Tipula (V.) kuwaymai can be recognized by the unarmed gonocoxite and by the ninth tergite forming a sclerotized, oval saucer which has an elevated edge anteriorly and is yellow posteriorly with the posterolateral angle blade-shaped. The wing is distinctly patterned with brown. The female has the cercus brownish yellow with the tip narrowed and upturned, and the ventral margin has distinct serration. The hypovalva is filamentous. The median incision between hypovalvae is slightly deeper than posterior margin of eighth sternite.
Head. Vertex and occiput gray with brown median line. Rostrum dark brown, dorsally dusted with gray. Nasus small, almost lacking. Antenna 13-segmented, if bent backward extending beyond the wing base. Scape and pedicel reddish yellow, flagellum dark brown. Each flagellomere except first one with distinct basal enlargement and incision. Apical flagellomere small, reduced. Verticils longer than corresponding segments. Palpus dark brown.
Thorax. Pronotum gray with brown median line. Prescutum and presutural scutum gray. Median stripes anteriorly gray, posteriorly brown, bordered by darker brown, fused at base. Lateral stripes blackish gray, bordered by brown. Postsutural scutum blackish gray; each lobe with light brown spot bordered by brown. Scutellum and postnotum brownish, dusted with gray, each with brown median line. Pleura brownish, dusted with gray. Wing distinctly patterned with brown. Halter pale with brown knob. Coxa gray; trochanter yellow; femur brownish yellow with tip dark brown; tibia and tarsal segments brown. Tarsal claw with tooth.
Known distribution. Russia, Japan China (Oosterbroek, 2019) and North and South Korea. Recorded here for the first time from the Korean Peninsula.
Tipula (Vestiplex) serricauda Alexander, 1914 Figs 30-55, 88 Tipula serricauda Alexander 1914: 237;1920b: 18. Tipula asio Alexander 1918: 68 (synonymy after Alexander 1953. Diagnosis. Tipula (V.) serricauda can be recognized by the gonocoxite being armed with a black spine and the ninth tergite divided by pale membrane with ventral portion yellow and bearing a pair of blackened lobes. The body is yellowish, with short antenna reaching the pronotum if bent backward. Female can be recognized by the short, plateshaped hypovalvae.
Head. Yellowish dusted with gray, vertex and occiput yellowish, with dark brown median line. Rostrum yellowish with conspicuous nasus. Antenna 12-segmented, if bent backward reaching pronotum. Scape, pedicel, the first and second flagellar segments yellow; flagellar segments 3-10 darkened at base and yellow apically; remaining segments dark brown. Each flagellomere, except first one, with small, inconspicuous enlargement. Apical flagellomere very small, reduced, distinctly shorter than preceding segment. Verticils longer than corresponding segments. Palpus dark brown.
Thorax. Brownish yellow. Pronotum gray with brown median line. Prescutum and presutural scutum with four longitudinal, grayish-brown stripes bordered by darker brown. Intermediate pair brownish, fused anteriorly and posteriorly, separated in the first third. Lateral stripe grayish. Interspace between median and lateral stripes light brown. Postsutural scutum yellowish, dusted with light gray; scutal lobe with two yellowish spots. Scutellum yellowish; postnotum yellowish, lightly dusted with gray with brown median line. Pleura brownish yellow, lightly dusted with gray. Coxa yellowish; trochanter yellow; femur yellow, distally brown; tibia yellowish brown; tarsal segments dark brown; claw with tooth. Wing distinctly patterned with brown. Halter yellow, knob brown with distal part pale yellow.
Larva (N = 1). Length 29 mm, width 4 mm. Body light brown (Figs 42-44). Head capsule. Length 2.3 mm, width 1.2 mm. Head capsule prognathous, hemicephalic, oval, slightly depressed dorsoventrally, and heavily sclerotized (Figs 45, 46). Internolateralia and externolateralia separated by incisions which reach almost middle of head capsule. Externolateralia widely separated ventrally (Fig. 46). Premaxillary suture separates side plate from rest of head capsule. Side plate wide, elongated, with two sensory pits and two long setae anteromedially; a short seta located posteromedially (Fig. 47). Hypostomium asymmetrical, basally fused with ventral margins of genae and side plates; bearing eight sharp teeth: four on left side, most prominent tooth in middle, and three on right side (Fig. 48). Prementum visible from below, bearing five large, sharp teeth on anterior margin; sides of prementum strongly sclerotized (Fig. 49). La- bial area entirely covered with firm bristles and bearing a pair of cone-shaped palpes. Prementum dorsally fused with hemispherical and membranous hypopharynx which is covered with numerous short hairs. Lateral arm of hypopharynx curved and strongly sclerotized. Frontoclypeus fused with internolateralia. Clypeal part of frontoclypeus membranous, frontal part sclerotized. One long seta and three sensory pits on anterior part of clypeus; three short setae near inner margin of antenna (Fig. 50). Clypeolabral suture obscure. Dorsal ecdysial sutures (frontal sutures) present, meeting each other posteriorly and forming a short median coronal suture. Ecdysial sutures enclose Vshaped frontoclypeus and extend anteriorly only to base of clypeus. Labrum trapezoidal and composed of two triangular plates separated by membranous area (Fig. 50). Apical part of labrum and epipharynx covered with numerous, short hairs. Membranous part of labrum with a pair of medium-long setae in middle. Labral plates sclerotized only posteriorly and bearing numerous long firm spines on outer margin. Each plate bears  a long seta, one long and two very short papillae on anterior part, one long seta almost at middle, and a sensory pit on postero-lateral part (Fig. 51). Antenna elongated, cylindrical. It has just one cylindrical segment, which is three times as long as wide at base (Fig. 51). Apically it has one small cone-shaped and several (exact number difficult to establish) small, peg-like sensillae; dorsally it has a sensory pit near middle. Mandible 1-segmented and more sclerotized than rest of head capsule, armed with four teeth (Fig. 52). Apical tooth is the most prominent; first dorsal and ventral teeth smaller than apical; second dorsal tooth smallest. Prostheca or lacinia mobilis present on dorsal side of mesal mandibular base; prostheca sclerotized, distinctly widening distally, and set with numerous hairs. Lateral margin of mandible with two long setae near base; a sensory pit present at base of dorsal side of mandible. Mandibles operate in horizontal plane. Conspicuous larval eye spot present below base of mandible. Maxilla consists of cardo and outer and inner lobes. Cardo wedge-shaped, bearing two long setae near distal end and a long seta near its base (Fig. 53). Outer lobe (stipes) sclerotized, except apex, which bears prominent, cylindrical palpus with several sensory structures. Short sensory structure and several long, sclerotized spines (exact number difficult to establish) on inner margin of stipes. Inner lobe (galea fused with lacinia) ventrally bears elongated, narrow sclerite extending around inner margin onto its dorsal surface; diamond-shaped sclerite present dorsally at base (Fig. 53); apical part with numerous short hairs, three long setae, and prominent sensory structure. Lacinia armed with several stout bristles and bears a ridge with sclerotized spines on outer margin.
Thorax. All thoracic segments wider than long. Anterior part of second and third segments covered with much denser pubescence than posterior (Figs 42-44).
Abdomen. First abdominal segment almost twice as long as wide. Abdominal segments II-VII almost as long as wide. All abdominal segments except last one covered by short microscopic hairs arranged into transverse rows, which are interrupted by pubescence on ventral and dorsal sides. Most macrosetae dark brown except L2 and L3. Dorsal setae D2 and D3 longest; seta D1 only slightly shorter than D2 and D3; setae D4-D6 short and appressed, more than three times shorter than D2 and D3. Setae D2 + D3 and D5 + D6 close to each other and separate from others. Lateral setae L2 and L3 very short and pale; L1 and L4 long and almost equal in length; L2 dorsolateral to L1. Setae L1, L4 more than four times as long as L2 and L3. V2 almost equal to V3 and both the longest of ventral setae. Setae V4 and V5 slightly shorter than V2 and V3. Seta V1 very short, more than five times shorter than V2 and V3.
Anal division. Dorsal and lateral lobes of spiracular disc subconical, lateral lobes in dorsolateral position (closer to dorsal than to ventral lobes). Dorsal and lateral lobes similar in length, twice as long as wide at base (Fig. 54). Ventral lobe very small, triangular, its length almost equal to width at base. Ventral lobe almost five times as short as dorsal or lateral lobe. Dorsal lobe completely sclerotized, with apex extended into acute, anteriorly directed point (Fig. 55). Lateral lobe with long, narrow, curved, dark sclerite that starts near base of spiracle and extends to mid-length of lobe; a long seta present in middle of outer edge of lobe. Ventral lobe with three small, dark spots at base; outermost spot most prominent. Distal half of lobe sclerotized, with long apical seta. Spiracle subcircular, inner circle black, outer ring brown; distance between spiracles almost twice diameter of a spiracle. Remaining area around spiracles white and glabrous. Four white, fleshy anal papillae arranged into anterior and posterior pairs. Anterior papilla broadly rounded; posterior papilla more elongated (Fig. 54). A brown band separates anus and anal papillae; this band connected to marginal band.
Habitat. Larvae were found under leaf litter and woody debris accumulated on boulders. Two identical last instar larvae were collected and one of them was kept for rearing. A female emerged after 36 days and identified as T. Each dorsal lobe of this species is sclerotized both anteriorly and posteriorly, with each apex forming an acute, strongly anteriorly directed point. Each lateral lobe has a long, narrow, curved, dark sclerite, extending from near the base of a spiracle to the midlength of each lobe. Each ventral lobe has a sclerotized distal part with a long apical seta, the base of each lobe with three small dark spots, with the narrow band missing. Sclerotization of the spiracular field of the fourth group most resembles that of larvae of T. (Triplicitipula) but not as seen in other groups of the subgenus T. (Vestiplex). The macrosetal arrangement on the dorsum and venter of the abdomen appears to be consistent in the subgenus, but the arrangement of the abdominal lateral setae is species-specific. Head capsules have never been comparatively studied in detail for the genus Tipula or the subgenus T. (Vestiplex); thus, comparison has been impossible among species and subgenera. Other examined material (Fig. 89). NORTH KOREA, 1 male, Seren Mts, alt. 3500 ft, 25 June 25 1938, Yankovsky (USNM); 1 female, MONGOLIA, Tov Aimag, Erdene Soum, Gorkhi Terelj National Park, unnamed tributary of Tuul River on its west side, 1.6 km upstream from Daichin crossing, 48.21780°N, 107.90392°E, alt. 1600m, 9 July 2003.
Diagnosis. Tipula (V.) thukchi can be recognized by the unarmed gonocoxite and the ninth tergite forming a concave, roughly rectangular, sclerotized saucer. The body coloration is blackish yellow, and the wing pattern is indistinct. The female has the cercus with an apical incision and outer margin rough and distinctly serrated. The eight sternite has a distinct lateral incision, and the hypovalvae are filamentous.
Male. Body length 16.8 mm, wing length 17.1 mm. General body coloration blackish yellow.
Head. Gray, vertex and occiput gray with brown median line. Rostrum brown, dorsally dusted with gray. Nasus short. Antenna 13-segmented, if bent backward extending beyond the wing base. Scape and pedicel yellowish; first flagellar segment brownish; subsequent flagellar segments dark brown. Each flagellomere except first one with basal enlargement and moderately incised. Apical flagellomere small, reduced. Verticils shorter than corresponding segments. Palpus dark brown.
Thorax. Brown, dusted with grey. Pronotum blackish, gray dusted, with brown median line. Prescutum and presutural scutum brown, grey pruinose with four longitudinal stripes bordered by brown. Intermediate pair fused into brown median line. Interspace between median and lateral stripes light gray. Postsutural scutum blackish, gray pruinose with median line. Scutal lobe with two spots bordered by brown. Scutellum brown, postnotum brown, dusted with gray-brown; both sclerites with darker median line. Pleura brown, dusted with gray. Coxa brown, grey pruinose. Trochanter, femur, and tibia yellowish. Tarsal segments brown. Distal part of femur and tibia dark brown. Tarsal claws toothed. Wing pattern indistinct, only weak darkening along vein CuA. Halter yellowish, with brown knob.
Hypopygium. Brownish black. Ninth tergite forming a large, concave, roughly rectangular sclerotized saucer. Main body of tergal saucer brown and rim blackened (Fig. 56). Posterior margin of tergal saucer toothed with small denticles, broadly emarginated, with deep median U-shaped notch. Lateral angles of tergal saucer obtuse, broadly truncated. Anterior and lateral portions of tergal saucer raised into sclerotized border; border laterally produced into obtuse point directed caudad and situated under lateral angle of tergal saucer so that ninth tergite with two teeth in lateral view. Gonocoxite unarmed (Fig. 57). Outer gonostylus flattened, slightly curved, with apex rounded (Fig. 58). Inner gonostylus in the shape of a curved plate, terminating dorsally with obtuse tooth; beak claw-shaped (Fig. 59). Gonocoxal fragment large, with lateral and medial sclerites well developed (Fig. 60). Medial sclerites fused anteriorly into long, narrow apodeme; posteriorly with rounded apodeme; lateral parts broadened and arched. Lateral sclerite large and bilobed, expanded at base. Adminiculum canoe-shaped (Fig. 61). Semen pump with central vesicle relatively small and flattened (Figs 62, 63). Compressor apodeme with broad median incision, forming a 50° angle with posterior immovable apodeme. Posterior immovable apodeme approximately as long as compressor apodeme. Anterior immovable apodeme rounded. Intromittent organ tube-shaped, about four times as long as semen pump, basally and medially brown, passing into yellow towards apex. Distal part ventrally truncated, shovel-shaped, with rough edge and two stripped fragments (Fig. 65).
Female. Female not known from Korean Peninsula, but can be recognized by cercus having apical incision and rough and distinctly serrated outer margin (Fig. 65). Hypovalva filamentous, flattened, broadened at base, distally pale, with short trichia at tip (Fig. 66). Median incision between hypovalvae deeper than posterior margin of eighth sternite; lateral incisions distinct.
Known distribution. Finland, Sweden, Russia, and Mongolia (Oosterbroek 2019 Diagnosis. Tipula (V.) verecunda can be easily recognized by the eighth sternite laterally having long setae and the ninth sternite being ventrally produced into a small tubercle. The ninth tergite has a U-shaped notch posteriorly, and anterior to the notch, the tergite is divided by a pale membrane. The ventral portion of the ninth tergite is yellow, with a pair of blackened narrow plates, and the gonocoxite is unarmed. The thorax is grey, with four darker grey stripes narrowly bordered by brown, and the wing is distinctly patterned with dark brown. The female can be recognized by the cercus having a smooth margin and a long, blade-shaped hypovalvae.
Head. Vertex and occiput ochraceous yellow, with dark median line. Rostrum dark brown, dorsally narrowly ochraceous yellow. Nasus distinct. Antenna 13-segmented, if bent backward extending beyond the wing base. Scape and pedicel yellow; flagellum brownish black. Each flagellomere, except for first one, with weak basal enlargement. Apical flagellomere small, reduced. Verticils longer than corresponding segments. Palpus dark brown.
Thorax. Pronotum ochraceous yellow, with dark median spot. Prescutum and presutural scutum grey, with four darker grey stripes, narrowly bordered by brown. Intermediate pair fused anteriorly. Interspace ochraceous light yellow. Postsutural scutal lobe with two ochraceous brownish yellow spots bordered by brown. Scutellum brown, with broad, dark brown median line. Postnotum brownish, with pale median line, and dusted with gray. Pleura yellowish. Wing distinctly patterned with dark brown. Halter pale, with brownish-black knob. Coxa yellowish; trochanter yellow; femur basally yellow, passing into brown towards dark brown tip. Tibia and tarsal segments brownish black. Tarsal claw with tooth.
Outer gonostylus nearly oval, with basal part narrowed (Fig. 72). Inner gonostylus in the shape of rounded sclerite, terminating into a short upper beak with a small lower beak; beaks separated by round incision (Fig. 73). Dorsal crest with yellow setae and short, black spines grouped on dorsal surface, edge basally bent outward. Adminiculum nearly parallel-sided in ventral view, fused medially forming a distinct sclerite ( Fig. 74). Basal part of adminiculum broadened and raised; apex funnel-shaped, with preapical incision in ventro-lateral view (Fig 77). Ninth sternite ventrally produced into small tubercle (Figs 67, 74). Appendage of ninth sternite with ventral lobe oblong, tip narrowed, surface with setae (Figs 74, 76). Dorsal lobe in the shape of flattened, curved plate; tip on inner surface provided with setae (Figs 74, 75). Eighth sternite posteriorly with pale median area; laterally provided with long setae reaching 1.1 mm long. Semen pump with central vesicle swollen (Figs 78, 79). Compressor apodeme flattened forming a 50° angle with posterior immovable apodeme. Posterior immovable apodeme shorter than compressor apodeme, narrowed. Anterior immovable apodeme narrow. Intromittent organ tube-shaped, about three times as long as semen pump, basally and medially brownish yellow, passing into yellow towards acute apex.
Female. Body length 27.3-28.7 mm, wing length 23.0-24.5 mm. Generally similar to male. Thorax brown. Abdomen with distinct median stripe. Tergites and sternites with lateral margin pale.
Known distribution. Russia, Japan, and China (Oosterbroek 2019). Recorded here for the first time from South Korea.