Macrocera interrupta, Lim & Bang & Shin, 2025

Lim, Wonseop, Bang, Woo Jun & Shin, Seunggwan, 2025, New records of Macrocera Meigen 1803 (Diptera, Keroplatidae) from the Korean Peninsula with description of a new species, Zootaxa 5665 (2), pp. 239-255 : 240-245

Macrocera interrupta sp. nov.

urn:lsid:zoobank.org:act:63607DFA-0248-4DB0-8226-AE50AD0819B7

Figs. 2–4

Type material. Holotype. Male ( SNUE), Wando Recreational Forest , Wando-gun , Jeollanam-do, South Korea (34°21'11.7"N, 126°42'03.2"E; Fig. 1 ), dry pinned. Terminalia not cleared. Left antennae lost, right antennae intact.

Paratypes. Four females and one male ( SNUE), same collection as holotype, dry pinned. Terminalia cleared in male paratype and mounted on slide. All specimens collected in May 27, 2022, by Woo Jun Bang, Sangjin Han, and Jonghwan Choi using light trap .

Diagnosis. Adult. This species can be distinguished from other species with similar coloration and wing markings based on the combination of following features: male antennae twice as long as body length, lack of striped patterns in the mesonotum, dark markings at the frontmost lateral scutum, banded patterns in the abdomen that are black at anterior and yellow at posterior, and two apical teeth almost parallel and subequal in length in male terminalia. See remarks for detailed comparison with other resembling species.

Description. Adult Male (Holotype) ( Fig. 2a ). Head. Yellowish brown with ocelli-marginal area dark brown; three ocelli present in equilateral triangular form with each ocellus being approximately equal in size; vertex wide and with dark setae; clypeus setose; antennae 10.8–11.8 mm (mean 11.3 mm, n=2) long, about two times longer than body length; scape yellowish brown and bulbous with sparse and short dark setae; pedicel short and yellow, cylindrical, with short setae sparser than on scape; flagellum yellow and gradually darker apically, about three times longer than whole body, with dense short dark setae; palpus yellowish brown. Thorax ( Figs. 3a–b ). Yellowish brown overall; scutum and mediotergite gradually darker apically, being darkest in anterior and posterior margins of scutum; mesonotum lacking conspicuous stripe patterns; mediotergite bare; acrostichal setae absent and dorsocentral setae in only one row, lateral setae distinct and numerous; scutellum sparsely setose; distinctive dark spot on the 1/3 of frontmost lateral scutum; anepisternum and katepisternum mostly dark brown, with only few setae; anepimeron, laterotergite bare; anepimeron mostly yellowish brown and occasionally bit darker on lowermost part; dark spot on the posterior part of the laterotergite; pronotum dark with few setae. Wings ( Fig. 4a ). Length 3.9–4.5 mm (mean 4.2 mm, n=2); hyaline and with distinctive markings; veins dark brown and radial, medial, cubital veins setose; distal tip of R1 slightly thickened, distal half of mcu less pigmented; distal 1/3 of the wing slightly darker; dark brown or black spot near distal tip of R 1 with fibrous longitudinal pigmentation extending proximally in parallel with R 1, another spot on the triangular region surrounded by proximal R4+5 and M4 which extend diffusively reaching vein CuA, small region near distal end of Sc and proximal Rs also pigmented but less prominent, sometimes absent; wing membrane covered with microtrichia, macrotrichia absent; costa ending at medial point between R 5 and M 1; R 5 highly curved at 1/3 from distal end; length of R 4+5 2/3 of R 5; R 4 curved at point 4/5 from distal end and ending in costa, and 2/5 as long as R 4+5; A 1 reaching wing margin and CuP not reaching wing margin; A 2 less prominent and arranged parallel to proximal anal margin, not reaching wing margin; anal margin almost in right angle, with proximal anal margin being slightly concave. Halters. Pale yellowish brown, covered with few short setae. Legs. Long, slender and covered with short setae, yellow to yellowish brown in color, apical part of coxa and tarsi darker; coxa of midleg and hindleg about 2/3 of foreleg; length of femur and tibia becoming longer from foreleg to hindleg, and femur of midleg and hindleg darkened at distal end; tibial spurs subequal or slightly longer than tibial width. Abdomen. Highly setose; first tergal segment yellow but may have dark pigmentation; second to fourth tergal segments dark brown or black at anterior and yellow at posterior, with variable widths but bands almost always parallel to each other rather than being inclined; fifth to eighth tergal segments black. Terminalia. ( Figs. 4b–d ) Dark brown to black overall with numerous long setae; cerci oval and width about 1/3 of length; gonocoxites slightly longer than gonostylus; width of gonostylus about half of gonocoxite, and with two pincer shaped apical teeth that are almost parallel and subequal in length forming about 120 degrees with gonostylus; inner apical teeth slightly stockier than the outer apical teeth.

Adult Female ( Fig. 2b ). Mostly similar with male but eighth tergite yellow. Antennae 5.4–6.6 mm (mean 5.8 mm, n=4), shorter than male and slightly longer than body length. Wing length 3.9–4.2 mm (mean 4.1 mm, n=4). Larva. Unknown.

Remarks. This species resembles Macrocera abdominalis Okada 1937 , recorded from Japan and Far East Russia, in terms of similar wing markings and the absence of striped patterns on the scutum ( Okada 1937; Okada 1939b). However, Macrocera interrupta sp. nov. can be clearly distinguished by its abdominal coloration. The original description of M. abdominalis indicates a presence of spotted patterns on the abdomen ( Okada 1937), which is in contrast with the banded tergites of M. interrupta . Also, the antennae of male M. abdominalis are about three times longer than the body, whereas these of M. interrupta are only about two times longer. M. interrupta is also similar to Macrocera angulata Meigen 1818 from Europe, which lacks a striped pattern on the scutum and has a banded pattern on the abdomen. However, the wing markings of M. angulata differ from M. interrupta as it has a medial band traversing the wing vertically and dark band patterns of the abdomen that are present in the posterior of each tergal segment rather than the anterior. M. angulata also lacks markings at the lateral margin of scutum. Two additional Palaearctic species— Macrocera fascipennis Staeger 1840 and Macrocera phalerata Wiedemann 1818 —also lack or only have a weak striped pattern on the scutum and banded pattern on its abdomen. However, the wing markings of M. fascipennis differ considerably from M. interrupta as it has an additional spot between M 4 and CuA, and the antennae of the male M. fascipennis are much shorter, barely exceeding the body length. Wing markings of M. phalerata is very similar to M. interrupta but the angle between two apical teeth in male terminalia is much larger in M. phalerata rather than being parallel ( Zaitzev 1994, Fig. 35.5). In addition, differently from M. iterrupta , M. phalerata has wing membrane with macrotrichia.

Habitat. All specimens were collected in a temperate mixed forest on Wando Island in May 2022 using light trap.

DNA Sequences.Partial COI gene of three specimens sequenced, two females (Accession:PP869430, PP959173) and one male (Accession: PP960232), as well as 16S (Accession: PP868177), 18S (Accession: PP868177), 28S (Accession: PP868176) genes.

Etymology. The new species was named based on distinctive dark spots on both sides of lateral scutum, which resembles the incomplete stripe pattern.

Figures

FIGURE 1. The map of the sampling localities. Map adopted from Kim (2023).

FIGURE 2. Macrocera interrupta sp. nov. a. Male habitus, lateral view. b. Female habitus, lateral view. (scale bar 1.0 mm)

FIGURE 3. Macrocera interrupta sp. nov. Thorax, male, a. lateral view. b. dorsal view. (scale bar 1.0 mm)

FIGURE 4. Macrocera interrupta sp. nov. a. Wing, female. (scale bar 1.0 mm) b. Male terminalia, dorsal view. c. ventral view. d. dorsal view, tergite 9 removed. (scale bar 100μm)