Macrocera abdominalis Okada 1937

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 : 245-246

Macrocera abdominalis Okada 1937

Figs. 5–6 , 9a

Material examined. One male ( SNUE), Yongdae Recreational Forest , Inje-gun, Gangwon-do, South Korea (38°14'33.0"N, 128°20'11.3"E; Fig. 1 ), dry pinned, terminalia cleared and mounted on slide. Collected during May 16 to June 22, 2023, by Woo Jun Bang, Sangjin Han, and Jonghwan Choi using Malaise trap . One female ( SNUE), Odaesan Mountain , Pyeongchang-gun, Gangwon-do, South Korea (37°47'24.0"N, 128°33'52.7"E; Fig. 1 ). Collected during July 12 to August 4, 2022, by Woo Jun Bang, Sangjin Han, and Jonghwan Choi using Malaise trap .

Comments. Preservation quality of the specimens was not very good, but following characters made the identification possible: spotted patterns on the abdomen of male both on the dorsal ( Fig. 5a ) and ventral ( Fig. 5b ) sides, uniformly reddish-yellow colored mesonotum ( Fig. 9a ), antennae very long in male being almost three times the body length ( Fig. 5a ), and a wing pattern ( Fig. 6a ) matching that of the figures by Okada (1937, 1939b). Abdominal spots are much thickened in the female, forming almost a striped pattern, which also matches the Okada’s (1937) description ( Fig. 5c ). This species is somewhat similar to M. interrupta including the structure of male terminalia, which have been figured for the first time in the current study ( Figs. 6b–d ). However, some distinctive features can separate these two species as mentioned for M. interrupta , which is also supported by our NJ tree analysis ( Fig. 10 ). This species was only known from Japan ( Okada 1937, 1938a 1938b, 1939a, 1939b, Sasakawa 2005) and Far East Russia (Southern Kuril Islands; Okada 1937) so far.

DNA Sequences. Partial COI gene of both specimens sequenced: female (Accession: PV300948) and male (Accession: PV300949).

Figures

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

FIGURE 5. Macrocera abdominalis Okada 1937 a. Male habitus, lateral view. b. Male abdomen, ventral view. c. Female habitus, lateral view. (scale bar 1.0 mm)

FIGURE 6. Macrocera abdominalis Okada 1937 a. Wing, female. (scale bar 1.0mm) b. Male terminalia, dorsal view. c. ventral view. d. dorsal view, tergite 9 removed. (scale bar 100μm)

FIGURE 9. a. Macrocera abdominalis Okada 1937, thorax, male, dorsal view. b. Macrocera maculosa Matsumura 1915, thorax, male, dorsal view (scale bar 1.0 mm)

FIGURE 10. NJ tree of Macrocera species based on COI sequences. Black circles on the nodes represent bootstrap support values and radii of the circles are proportional to the support value of the node. Outgroup species Chiasmoneura anthracina de Meijere 1913 was used to root the tree.