Atypophthalmus (Microlimonia) jeju Podenas & Podeniene, 2020

Podenas, Sigitas, Podeniene, Virginija, Seo, Hong-Yul, Kim, A-Young, Park, Sun-Jae, Byun, Hye-Woo, Kim, Heung-Chul & Aukštikalnienė, Rasa, 2020, New Atypophthalmus (Diptera: Limoniidae) from South Korea, Zootaxa 4732 (2), pp. 281-294 : 286-292

Atypophthalmus (Microlimonia) jeju Podenas & Podeniene , sp. nov.

( Figs. 5 , 14–32 )

Diagnosis. A small to medium-sized crane fly, with body length reaching approximately 5 mm in the male and nearly 6 mm in the female. Antennae 15-segmented. Thorax pale yellow with distinct dark brown stripe along the pleuron, abdomen brownish gray dorsally and somewhat lighter ventrally. Male: Gonocoxite of male terminalia with large elongate ventro-mesial lobe with a straight distal end, and smaller rounded lobe at its base. Gonostylus egg-shaped with large, arched sclerotized rostral prolongation and smaller rounded subbasal tubercle reaching to the middle of the gonostylus. Female: Cercus of ovipositor short and narrow, distal part slightly turned upwards. Hypovalva long and straight, nearly reaching tip of cercus, with distinct black spot at base. Larva: Dorsoventrally depressed and slightly reduced head capsule, dorsal suture reaching only one third of the head capsule length. Labrum elongate-oval with dentate anterior part, mandible with six teeth, hypostoma with twelve teeth. Spiracular field with five short and blunt lobes, lateral lobe twice as wide as long, without sclerites, ventral lobe as long as width at the base and bearing a dark sclerotized, elongate and angulate sclerite. Pupa: Female pupa with flattened triangular pronotal horns, bases of which are very close to each other, apices separated. Legs reaching almost to the middle of fourth abdominal segment. Sheath of cerci and sheath of valvae are similar in length.

Material examined: Type specimens 24 males, 7 females, 4 larvae, 1 female pupa.

Holotype: male (pinned) ( Fig. 14 ), S. Korea, Jeju-do (do = Island), Dongbaekdongsan Ramsar wetland, N 33.51594, E 126.70744, alt. 110 m, 2017.05.23 (1), coll. S. Podenas, evergreen broad-leaved forest, entomological net.

Paratypes: 18 males, 9 females (pinned), 22 males, 6 females (in EtOH), 3 larvae and 1 female pupa (in EtOH), 1 larva (slide-mounted), topotypic, coll. S. Podenas, V. Podeniene, four of these males preserved at the Academy of Natural Sciences of Drexel University, Philadelphia, PA, U.S. A; 1 male (pinned), 1 female (in EtOH), S. Korea, Jeju-do , Hallasan National Forest , N 33.43222, E 126.59776, alt. 577 m, 2017.05.24 (1), coll. S. Podenas, entomological net .

Description. Adult, male (N=42), female (N=16).

General body color yellow with gray to brown abdomen. Body length of male 3.8–5.0 mm, of female 3.4–5.7 mm.

Head. Black dusted with grayish pruinosity. Eyes large, holoptic, nearly reaching each other dorsally. Antennae ( Fig. 15 ) entirely brown, 0.8–1.2 mm long in male, 0.9–1.2 mm in female, nearly reaching wing base if bent backwards. Scape elongate, approximately 1.5 times as long as wide, slightly widened distally. Pedicel egg-shaped, nearly as long as scape. Flagellum 13-segmented, flagellomeres oval with small apical pedicels, twelfth flagellomere elongate, apical flagellomere very small, distinctly shorter than the penultimate flagellomere. Longest verticils nearly as long as respective segments. Flagellomeres covered with sparse whitish pubescence. Rostrum yellow, slightly brownish dorsally at base. Palpus yellow, distal part of apical segment grayish.

Thorax. Generally yellow. Cervical sclerites dorsally grayish, laterally dark brown. Pronotum yellowish gray with dark brown lateral margin. Mesonotal prescutum grayish yellow, stripes absent, darkening, intensity of which depends on specimen, at the middle before posterior margin of sclerite. Scutal lobe with large drop-shaped brownish gray spot, widely yellow at frontal margin and pale yellow postero-lateral corner. Both lobes widely separated by pale yellow color. Scutellum grayish, widely yellow laterally. Mediotergite light gray frontally, dark gray posteriorly, with pale yellow frontal margin and narrow dark line along middle at posterior half. Pleuron pale yellow dorsally, whitish ventrally with distinct dark brown stripe extending from cervical sclerites through the base of the halter to the basal tergite of abdomen. Few setae on the katepisternum. Wing ( Fig. 5 ) subhyaline, unpatterned, with drop-shaped brownish stigma. Length 4.7–6.0 mm (male), 4.6–6.3 mm (female). Veins brown, pale at wing base. Venation: Sc medium-long, Sc 1 reaching to about one third of Rs length. Sc 2 slightly before apex of Sc 1. Rs mediumlong, slightly arched, or nearly straight, alternately angulate and short-spurred; variations occur on each specimen. Free end of R 1 short, transverse, very light and indistinct. R 2 some distance beyond tip of R 1. R 3 and R 4+5 arched, parallel to each other. Specimens with short-spurred base of Rs usually have short-spurred base of R 4+5. Discal cell missing by atrophy of basal part of M 3. Cell m 1+2 short-petiolate, with stem being nearly three times as short as cell itself. Basal deflection of CuA 1 close to branching point of M, sometimes slightly before or slightly beyond it. Both anal veins nearly straight, diverging. Anal lobe wide. Length of halter 0.7–1.0 mm (male) and 0.6–0.8 mm (female). Halter uniformly grayish, with distinctly pale base. Coxae pale, just frontal face of fore coxa distinctly darkened depending on specimen, distal margin narrowly dark brown. Trochanters pale with narrowly blackish distal margin. Legs uniformly brownish except yellowish base of femur. Male femur I: 4.0– 4.3 mm long, II: 4.5–4.6 mm, III: 4.5–5.1 mm, tibiae I: 4.9–5.6 mm, II: 4.7–5.1 mm, III: 4.8–5.5 mm, tarsus I: 4.5–6.5 mm, II: 4.3–5.0 mm, III: 3.8–4.5 mm. Female femur I: 3.5–4.5 mm long, II: 4.1–4.8 mm, III: 4.2–5.6 mm, tibiae I: 4.5–5.5 mm, II: 4.2–5.4 mm, III: 3.4–5.1 mm, tarsus I: 4.2–5.0 mm, II: 4.1–5.1 mm, III: 3.6–4.0 mm. Claw with subbasal spine in male, spineless in female.

Abdomen. Abdominal tergites brownish gray. Membrane between tergites and sternites pale with distinct dark spots where separate segments meet. Basal sternite pale yellow, succeeding three sternites pale at base and grayish distally, remaining sternites grayish, lighter than tergites. Male terminalia ( Fig. 16 ): yellowish dark gray with distinctly pale yellow aedeagus. Posterior margin of ninth tergite widely rounded with indistinct emargination medially. Gonocoxite elongate with large elongate ventro-mesial lobe, distal apex straight rather than rounded, smaller round- ed lobe at its base. Gonostylus egg-shaped with large, arched, sclerotized rostral prolongation and smaller rounded subbasal bump reaching to the middle of gonostylus. Paramere with wide blackened hook-shaped prolongation of mesial margin. Penis wide and long, reaching beyond tip of paramere, apex shallowly bifid. Female: Ovipositor yellow ( Fig. 17 ). Tenth tergite slightly darkened along dorso-posterior margin. Cercus short and narrow, distal part slightly raised. Hypovalva long and straight, nearly reaching tip of cercus, with distinct black spot at base.

Larva (N=4). Length 8.8–9.8 mm, width 0.5–0.6 mm. Body white.

Head. Head capsule 1.0 mm long and 0.6 mm wide, oval in shape, depressed dorsoventrally and slightly reduced, dorsal suture reaches only one third of head capsule length ( Fig.18 ). Labrum elongate-oval with numerous sensory structures: short seta medially of anterior part and three short setae on antero-lateral part, sensory circle area with two sensory papillae inside and two separate sensory pits located near the postero-lateral side. Anterior part of labrum dentate ( Fig. 19 ). Clypeus distinctly divided from labrum, consisting of sclerotized narrow postclypeus and membranous wide preclypeus. A long seta located near the antero-lateral side of preclypeus and sensory pit below it. A long seta and sensory pit located on postero-lateral part of preclypeus. Frons separated from clypeus, fused with internolateralia, wide, and T-shaped. A single sensory pit near the base of antenna and four sensory pits along the lateral margin of the widened part of frons. All five sensory pits arranged along straight axis. Caudal end of frons rounded ( Fig. 18 ). Basal segment of antenna cylindrical, less than 1.5 times as long as wide, with few very short sensory structures apically. Apical segment short, button-shaped. Sensory pit located at the middle of basal segment´s length ( Fig. 20 ). Mandible conus-shaped, with two large teeth similar in shape and size apically ( Fig. 21 ), three smaller triangular teeth on ventral side (basal tooth is the largest) and a well-developed sharp tooth on dorsal side. Maxilla well developed ( Fig. 22 ), stipes and galea large and similar in size. Stipes: two-thirds sclerotized, apical papilla button shaped with sensory structures on the apex, a small papilla (on outer margin) and sensory pit (on inner margin) below. Galea: basal part sclerotized, sensory papilla and sensory pit on inner margin of ventral sclerite, apical part covered with short setae, large sensory papilla (with small sensory structures inside) and small sensory papilla on apex. Cardo large, wedge shaped, long seta located near inner margin and short seta and sensory pit near outer margin of sclerite. Hypopharynx and prementum dentate ( Fig.23 ). Hypostoma bearing 12 teeth. All (except the middle and the most lateral teeth) are similar in shape and size ( Fig. 24 ).

Thorax. All thoracic segments wider than long. Second and third segments each with ventral creeping welt.

Abdomen. First, seventh and last abdominal segment less than 1.5 times as long as wide. Second abdominal segment more than twice as long as wide. Abdominal segments III–VI more than three times as long as wide. First segment with ventral creeping welt only, segments II–VII with dorsal and ventral creeping welts ( Fig. 25 ). Creeping welts with brown spines, arranged into longitudinal rows.

Anal division. Spiracular field very small, with five short blunt lobes, dorsal and lateral part inclined inward ( Fig. 26 ). Dorsal lobe vestigial with a pair of long setae at apex. Lateral lobe twice as wide as long, not covered with sclerites, two long and one short seta located at the margin. Ventral lobe as long as width at the base and bears a dark sclerotized, elongate and angulate sclerite. One short and three long setae located at the apex of each lobe. Spiracular field fringed with long firm setae ( Fig. 27 ). Spiracle large, oblong, placed obliquely and inclined dorsally.Anal field consists of two pairs of blunt, white, fleshy anal papillae.

Pupa, female (N=1). Male pupa unknown. Female pupa 8.5 mm long, 1.3 mm wide. Abdomen yellowish white ( Figs. 28, 29 ). Head, thorax, wings, legs and terminal segment dark brown, darker than the rest of the body.

Head. Cephalic crest absent. Surface non-setose. Antennal sheaths short, only slightly extending beyond base of wing ( Fig. 30 ). Labrum trapezoid with bluntly rounded apex. Labial lobe diamond-shaped. Maxillary palpus broad, transversal.

Thorax. Pronotal horns flattened, triangular, wide at the base and gradually tapering toward the apex, twice as long as width at the base ( Fig. 31 ). Base of horns very close to each other, apices separated. Dorsum of thorax nonsetose. Apex of wing reaching the end of second abdominal segment ( Fig. 30 ). Legs reaching almost to the middle of fourth abdominal segment. The innermost pair of legs are the longest, the outermost pair – the shortest ( Fig. 30 ).

Abdomen. Segments III–VII with dorsal and ventral creeping welts. Surface of abdominal segments non-setose. Spiracles hardly visible. Terminal segment elongate ( Fig. 32 ). Sheath of cerci and sheath of valvae are similar in length. Additional spines absent.

Habitat. Deciduous broad-leaved forest ( Fig. 33 ). A. (Microlimonia) jeju Podenas & Podeniene was the most abundant crane fly species at the type locality. Larvae and pupa were found under the bark of truncated deciduous tree trunks in sap with fungi.

Elevation. 100–600 m.

Period of activity. Collected only at the end of May.

Distribution. Currently known only from Jeju Island, Republic of Korea ( ROK).

Etymology. Species is named after Jeju Island, ROK, where it was collected.

Remarks. Analysis of mitochondrial DNA Cytochrome c oxidase subunit I barcoding region showed no difference in sequences of adults and larvae (GenBank accession numbers MN715236 and MN715237 ), leaving no doubts that they belong to the same species.

Atypophthalmus jeju sp. nov. could be grouped with two other East Palearctic species, A. egressus ( Alexander, 1938) from Sichuan, China and A. omogoensis ( Alexander, 1954) from Shikoku, Japan. All have similar general appearance, structures of male terminalia, and wing venation. Closest in general structure is A. egressa . The male terminalia of all three species have an elongate gonocoxite with a very large elongate bilobed ventro-mesial lobe. Both lobes in A. jeju sp. nov. are distinctly different in size, the dorsal being distinctly shorter than the ventral, while both lobes are nearly equal in size in A. egressus and A. omogoensis. The gonostylus is single in all three species, but in A. omogoensis it is trilobed, rostral prolongation twice as long as gonostylus itself, bilobed in A. jeju sp. nov. and A. egressus , but in A. egressus , the gonostylus is smaller, bifid at apex with a very elongate rostral lobe, which is distinctly longer than the gonostylus. The gonostylus in A. jeju sp. nov. is distinctly larger, the dorsal lobe is very small and does not reach the tip of the ventral lobe, the rostral prolongation distinctly shorter and not exceeding the length of the gonostylus. The meso-apical lobe of the paramere narrow with apex acute in A. egressus and A. omo- goensis, but wider and blunt at apex in A. jeju sp. nov. The wing has an open discal cell in A. jeju sp. nov., while A. egressus and A. omogoensis have a more a typical closed discal cell, as within the genus. Cell m 1+2 is short-petiolate in A. jeju sp. nov. with the stem nearly three times shorter than the cell, and long-petiolate in A. egressus , with the stem nearly as long as cell. The tip of vein Sc 1 reaches to about one third of Rs length in A. jeju sp. nov., but beyond the mid-length of Rs in A. egressus . A. jeju sp. nov. also differs by yellow coloration of rostrum and palpus, which are black or brown in both of the other species. A. jeju sp. nov. is the only Korean Atypophthalmus with an open discal cell, except some specimens of A. stylacanthus that may have an open discal cell ( Fig. 2 C in Podenas et al. (2017)).

The larva of A. (M.) machidai was described by Krivosheina (2010). Neither the head capsule nor the general appearance of that larva looks like a typical Limoniinae. We have doubts if Krivosheina’s identification is true, because no information is given on rearing. Because of that, no comparison is made between larvae of these two species. The larvae of A. (M.) machidai and A. (M.) jeju sp. nov. are very different.

In general appearance the larvae of the subgenera Atypophthalmus s.s. and Microlimonia are very similar. The body is white with dorsal and ventral creeping welts on abdominal segments II–VII. Head capsules of the subgenera Atypophthalmus s.s. and Microlimonia are similar: slightly reduced with short dorsal sutures, frons fused with internolateralia, elongate-oval labrum, clypeus divided into preclypeus and postclypeus, complete and dentate hypostoma. The larvae of both species have spiracular lobes reduced and spiracular fields with ventral pair of sclerites only.

Differences were noted in the shape of the frons, as well as the number of mandibular teeth, the number of hypostomal teeth, and the arrangement of sensory structures on the labrum. A. (A.) inustus larvae have eleven hypostomal teeth and a tridentate caudal end of frons, whereas A. (M.) jeju sp. nov. has twelve hypostomal teeth and a rounded caudal end of frons. Abdominal segments III–VI of A. (M.) jeju sp. nov. are almost three times as long as wide, whereas in A. (A.) inustus it is only twice as long as wide. The spiracular field of A. (A.) inustus has well developed ventral lobes, whereas A. (M.) jeju sp. nov. has lateral lobes and a vestigial dorsal lobe, all of which are inclined inward. A. (A.) inustus has a single short seta on the lateral margin and two long widely separated setae on the dorsal margin of the spiracular field. A. (M.) jeju sp. nov. has two long and one short setae on the lateral margin and two long setae, close in proximity, on the dorsal margin of the spiracular field.

The pupae of Atypophthalmus s.s. and Microlimonia are very similar in general appearance. Pupal head, thorax, wings, legs and terminal segment are dark brown, abdomen yellowish-white. Cephalic crest absent. The surface of head and thorax is smooth with laterally flattened pronotal horns.

The most significant difference is the shape of the pronotal horns, which are triangular in shape and wide at the base and narrowing toward the apex in A. (M.) jeju sp. nov., whereas in A. (A.) inustus they are narrow at the base and become wider medially. The shape of the pronotal horns of A. (M.) jeju sp. nov. is more similar to that of Achyrolimonia decemmmaculata ( Loew, 1873) . Another difference was in the length of the leg sheath. In A. (A.) inustus leg sheaths reach the fifth abdominal segment and end at the same level, whereas in A. (M.) jeju sp. nov. the leg sheaths reach nearly to the middle of fourth abdominal segment, the innermost pair longer and the outermost pair shorter than mid-pair.

The larval and pupal characters of Atypophthalmus (Microlimonia) that are listed in this paper allow preliminary placement of the subgenus among the Limoniinae. Characters were analyzed with the use of cladogram of nonquantitative analysis of phylogenetic relationship based on larval and pupal characters made by Oosterbroek & Theowald (1991), which is the most suitable. Atypophthalmus (Microlimonia) possess characters 18 (inner maxillary lobe with separate sclerotized plate), 19 (externolateralia strengthened), but lacks synapomorphy 9 (pupae in silken cocoon) and belongs to the clade Limoniinae. Atypophthalmus (Microlimonia) has synapomorphy 100 (pupal creeping welts elliptical), 101 (spiracles oblong or elliptical), 102 (spiracles placed oblique), 103 (larval segments 2 to 10 with creeping welts), but lacks character 99 (larvae in tube or case), placing this subgenus in Elliptera and Atypophthalmus – Discobola lineages. Presence of character 104 (spiracular lobes reduced) and absence of character 105 (caudal end of head capsule tridentate) separates this subgenus from the clade Atypophthalmus (Atypophthalmus) – Discobola .

The habitats of A. (A.) inustus and A. (M.) jeju sp. nov. are similar, with larvae developing under the bark of dead trees.

Figures

FIGURE 33. Habitat (type locality) of Atypophthalmus (Microlimonia) jeju Podenas & Podeniene, sp. nov.

FIGURES 1–6. Wings of Korean Atypophthalmus. 1: A. (Atypophthalmus) crinitus; 2: A. (A.) kleini Podenas, sp. nov.; 3: A. (A.) stylacanthus; 4: A. (Microlimonia) inelegans; 5: A. (M.) jeju Podenas, Podeniene, sp. nov.; 6: A. (M.) machidai. Scale bars 1 mm.

FIGURES 14–17. Atypophthalmus (Microlimonia) jeju Podenas, Podeniene, sp. nov. 14: male, holotype, general view; 15: male antenna; 16: male genitalia, dorsal view; 17: ovipositor, lateral view.

FIGURES 18–27. Larva of Atypophthalmus (Microlimonia) jeju Podenas & Podeniene, sp. nov. 18: general view of head capsule, dorsal aspect; 19: labrum and clypeus, dorsal view; 20: right antenna, dorsal view; 21: right mandible, dorsal view; 22: right maxilla, ventral view; 23: hypopharynx and prementum, ventral view; 24: hypostoma, ventral view; 25: general view, lateral aspect; 26: terminal segments, dorsal view; 27: spiracular field. Scale bars: 0.1 mm (18–24, 26, 27), 1 mm (25).

FIGURES 28–32. Female pupa of Atypophthalmus (Microlimonia) jeju Podenas & Podeniene, sp. nov. 28: general view, ventral aspect; 29: general view, lateral aspect; 30: head, thorax, I–IV abdominal segments, ventral view; 31: head, thorax, I–IV abdominal segments, dorsal view; 32: terminal segments, lateral view. Scale bars 1 mm.