A new species of Elephantomyia crane fly (Diptera, Limoniidae) from Jeju Island, South Korea

Abstract A new species of crane fly (Diptera, Limoniidae), Elephantomyia (Elephantomyia) hallasana Podenas & Podeniene, sp. nov., from Jeju Island, South Korea is described. Adult and larval characters are illustrated. Elephantomyia (E.) hallasanasp. nov. is the only species of the genus Elephantomyia Osten Sacken, 1860 recorded from Jeju Island, South Korea. Habitat, elevation range, and seasonality data are presented. Distributional notes on E. subterminalis Alexander, 1954 in the Far East of Russia (Khabarovskiy and Primorskiy regions) are discussed. An identification key for all Eastern Palaearctic species of subgenus E. (Elephantomyia) is presented.


Introduction
Crane flies belonging to the genus Elephantomyia Osten Sacken, 1860 are easily recognized by their long proboscis, which often exceeds body length (head + thorax + abdomen). The extended rostrum, with relatively small mouth parts and reduced palpi, is used for sucking nectar from tubular flowers (Savchenko 1986). Previously, only one and E. (Elephantomyodes) Alexander, 1923. The nominate subgenus includes 14 species, and the subgenus Elephantomyodes includes two species (E. sophiarum Ito, 1948 from Honshu and Kyushu, Japan, and E. tianmushana Zhang et al., 2015 from Zhejiang, China). Eastern Palaearctic species of the subgenus E. (Elephantomyodes) can be easily distinguished from species belonging to the subgenus E. (Elephantomyia), as they have snowy white tarsal segments and a very narrow anal angle of the wing. Only one species of the genus Elephantomyia, E. edwardsi Lackschewitz, 1932 was previously recorded from the Korean Peninsula (Podenas et al. 2015).
Key to the Eastern Palaearctic species of the subgenus Elephantomyia (Elephantomyia) Paramere of male terminalia with 4 or 5 spines distally (Fig. 4)   Diagnosis. Adult. It is a brown to light-brown species with banded abdomen. Body length 6.7-10.5 mm. Head gray and bearing rostrum that is approximately as long as abdomen. Mesonotal prescutum has distinct median and indistinct lateral stripes. Pleuron dark brown. Wing unpatterned except elongate light brown stigma. Abdominal tergites yellow to yellowish brown frontally, dark brown posteriorly, pattern more distinct in male. Abdomen of female darker than that of male with a very distinct light-yellow spot on the seventh tergite. Male genitalia with elongate gonocoxite, distal portion of which extends distinctly beyond bases of gonostyli. Outer gonostylus slightly angulate medially, with apex turned outwards and bearing small subapical tooth, inner gonostylus wide and non-sclerotized. The paramere armed with 4 or 5 teeth.
Larva. Medium-sized, 9-17 mm long. Body covered with long, golden hairs. Head capsule reduced, weakly sclerotized, elongated, posterior part consists of two pairs of rods. Mandible small, with two prominent apical teeth; antenna long, apical segment much longer than basal. Esophageal region strengthened with oblique parallel ctenoid sclerotized structures. Spiracular disc with lateral and ventral lobes, entirely covered with pale sclerites. Ventral lobe bears long apical seta.
Male abdomen. Distinctly bicolored, tergites and sternites yellow at base and distinctly dark brown along posterior margin. First tergite darkened at base and along distal margin, with yellow spot medially. Male terminalia (Fig. 2) dark brown. Sclerites of ninth segment fused and forming complete ring, posterior margin dorsally with wide and deep invagination. Dorsal surface of ninth tergite with two densely setose emarginations. Gonocoxite long and slightly arched with two pairs of gonostyli attached slightly beyond midpoint of gonocoxite. Distal part of gonocoxite, beyond bases of gonostyli, large, with rounded apex. Outer gonostylus slightly angulate medially with apex turned outwards, distal apex darkened and distinctly bidentate. Inner gonostylus longer than outer gonostylus, wide, fleshy, and setose. Paramere with four or five long spines distally forming a comb-like structure. Aedeagus shaped as a long, coiled tube.
Female abdomen. Generally darker than in male, somewhat glossy. Transverse yellow sutures on tergites vary depending on specimen, but narrower than in male, less distinct on basal segments and well developed on posterior segments. Sutures on tergites more distinct laterally, but narrower and less distinct along middle of sclerite. Distinct yellow lateral spots present on 3-7, 5-7, or only on seventh tergite (Fig. 1). Tergites and sternites brown basally, dark brown distally. Seventh tergite distinctly yellow with narrowly darkened posterior margin, covered with sparse, dark brown, erect setae. Seventh sternite dark brown with narrow yellow transverse suture at base. Tenth tergite dark brown basally, rusty brown distally, covered with sparse brownish pruinosity. Cercus brown, paler at base, long and narrow, distal part raised. Eighth sternite glossy dark brown, hypovalva brown, pale apex, long and narrow, reaching to about two-thirds of cercus.
Larva. Body brownish yellow (Figs 8-10). Length 7.8-8.6 mm, width 0.9 mm. Head. Head capsule 0.6 mm long, 0.15 mm wide, hemicephalic, elongated, weakly sclerotized and depressed dorsoventrally (Fig. 11). Genae reduced, posterior part of head capsule consists of one pair of rod-shaped internolateralia and one pair of rodshaped externolateralia, all bent medially, internolateralia and externolateralia joined by membrane. Labrum narrow, transversal, with numerous long hairs on epipharynx and a pair of sclerotized, comb-shaped premandibles, pair of sensory rings with two sensory papillae situated on anterior part of labrum (Fig. 15). Frontoclypeal apotome membranous with a pair of sensory pits on anterior portion, a pair of similar structures anterolaterally and four pairs of pits on lateral part. Mandible slender (Fig. 13), ventral and dorsal edges without prominent teeth, two prominent apical teeth, medially with two long acute spines. Maxilla (Fig. 14) short and weakly sclerotized bearing inner (fused galea and lacinia) and outer lobes, cardo long and narrow, with a single long apical seta. Inner lobe elongate-oval, with numerous apical hairs, with large area bearing small sensory structures distally, and with elongated narrow sclerite on inner margin. Outer lobe cylindrical with apical sensory structures, with numerous hairs on apical and lateral parts and with large irregularly shaped sclerite at the base. Antenna long, reaching apex of mandible, one-segmented with four short sensory papillae and one large apical papilla. Basal segment subcylindrical, short and sclerotized, apical papilla sculptured, elongate-oval and nearly twice as long as basal segment (Fig. 12). Both antennae close to each other. Ventral side of head with numerous long hairs in the maxillary area. Hypopharynx consists of two pairs of rods (Fig. 17). Labium membranous with three pairs of sensory papillae apically. Esophageal region strengthened with oblique parallel ctenoid sclerotized structures (Fig. 16).
Thorax. All thoracic segments wider than long, covered with long, golden, silky hairs. Abdomen. First abdominal segment wider than long. Second abdominal segment 1.5 times as long as wide. Abdominal segments II-VII almost twice as long as wide. Abdominal segments V-VII with ventral creeping welt each (Figs 9, 10). Creeping welt with brown spines, arranged into longitudinal rows. All abdominal segments covered with long, golden, silky hairs.
Anal division. Spiracular field surrounded by four (two lateral and two ventral) lobes (Fig. 18). Lateral lobe 1.5 times as wide as long, covered with pale sclerite surrounding spiracle, three short setae located at the outer margin of lobe. Ventral lobe as long as width at the base and entirely covered by pale sclerite. Very long seta, 2.5 times as long as lobe itself, located close to apex of lobe. One short bifurcated and two short single setae located at the apical part of each lobe. Two pairs of short setae located on the dorsal margin of spiracular field. Spiracular field fringed with short tiny setae except inner margin of lateral lobes (Fig. 18). Spiracle small, rounded, distance between spiracles more than two diameters of spiracle itself. Anal field consists of two pairs of blunt, white, fleshy anal papillae, which are retracted and hardly visible in studied specimens. Tuft of very long dense hairs located in front of anal field.
Etymology. The new species is named after the locality where it was collected, Hallasan National Park, which surrounds the highest mountain in South Korea, the shield volcano Hallasan.
Distribution. Currently known only from Hallasan National Park, Jeju Island, South Korea.
Habitats. Valley floor covered with deciduous trees and shrubs, and moss covered rocks (Fig. 20); deciduous forest with dense cover of bamboo-grass (Sasa quelpaertensis); park meadow with sparsely planted deciduous trees mixed with pines. Adults are attracted to light. Larvae were found under the bark of truncated deciduous tree trunks, in sap, with fungi together with Atypophtalmus (Microlimonia) sp. and Libnotes sp.
Elevation. Less than 600 m to 1100 m. Period of activity. Adults on wing from late May through middle of June.

Discussion
Elephantomyia hallasana sp. nov. is the only Elephantomyia species recorded from the Jeju Island. It is closely related to E. edwardsi (Figs 3, 7), which is recorded from the Korean Peninsula, and E. subterminalis (Fig. 4), which was described from Shikoku Island, Japan. The most striking difference of E. hallasana sp. nov. is the huge distal portion of the gonocoxite extending beyond the base of the gonostyli (Fig. 2) (Savchenko 1976(Savchenko , 1983) from the Russian Far East (Fig. 5) (Alexander 1920;Bangerter 1934;Wood 1952;Krivosheina 2010;Krivosheina and Krivosheina 2011). Immature stages of other three subgenera are still unknown. Based on this material, two different larval types could be distinguished: a moss-dwelling group with a massive, almost complete head capsule and reduced spiracular lobes (Afrotropical species: E. (E.) aurantiaca), and a dead-wood-inhabiting type with a strongly reduced head capsule and four-lobed spiracular field (Afrotropical, Palaearctic, and Nearctic species: E. According to Krivosheina (2010), species-specific differences of Elephantomyia larvae were noticed in the sclerotization pattern of spiracular fields and in spines of creeping welts. We found that species differ also in the ratio between the length of the ventral apical hair and the base width of the ventral spiracular lobe. Head capsules of different species are similar.
The larva of E. (E.) subterminalis from the Far East of Russia, Kedrovaya Pad and Ussuri Nature Reserves was described by Krivosheina (2010), but we have doubts about the determination of that species. The larva of E. (E.) hallasana sp. nov. is similar to the larva described by Krivosheina; the only difference is the length of the ventral apical seta, which is more than 2.5 times as long as the ventral spiracular lobe in E. (E.) hallasana sp. nov. and less than twice as long as lobe in the species from the Kedrovaya Pad and Ussuri Nature Reserves.
Two species of Elephantomyia, E. (E.) edwardsi and E. (E.) hallasana sp. nov., occur on the Korean Peninsula. Larvae of these two species differ in characters of spiracular field, such as the sclerotization of ventral lobes, ratio of length and width of the ventral lobe, and length of ventral setae. Ventral sclerites of E. (E.) edwardsi (Fig. 19) cover a larger part of the ventral lobe than in E. (E.) hallasana sp. nov. (Fig. 18), the ventral lobe in E. (E.) hallasana sp. nov. is just slightly longer than wider at base, whereas in E. (E.) edwardsi the ventral lobe is more than 1.5 times longer than wider at base, the length of ventral apical seta is more than 2.5 times as long as the ventral spiracular lobe in E. (E.) hallasana sp. nov. and less than twice as long as the lobe itself in E. (E.) edwardsi.