Olophrum mutatum Scheerpeltz, 1929

Shavrin, Alexey V., 2025, On some species of the genus Olophrum Erichson, 1839 (Coleoptera: Omaliinae) of the Eastern Palaearctic region, Zootaxa 5666 (1), pp. 93-104 : 95-97

Olophrum mutatum Scheerpeltz, 1929

( Figs 1–2 , 7–9 )

Olophrum mutatum Scheerpeltz, 1929: 100 ; Watanabe 1990: 129, Kim & Ahn 2015: 22

Type material examined. Holotype ( Fig. 2 ): ‘ ♂ ’ <printed>, ‘ex. | Coll. British | Mus. Nat. Hist’ <handwritten>, ‘Sharp Coll | 1905-313.’ <printed>, ‘Kin Kiang’ <small yellow oval label, handwritten>, ‘ Olophrum | vicinum, | D. Sharp’ <handwritten>, ‘ex. coll | Scheerpeltz’ <blue, printed>, ‘TYPUS | Olophrum | mutatum m. | O. Scheerpeltz’ <red, printed>, ‘ Olophrum | mutatum Scheerpeltz, 1929 | Shavrin A.V. det. 2025’ ( NMW).

Additional material examined. CHINA: HUBEI: 1 ♂ ( Fig. 1 ): 30 km NE Macheng. 500 m a.s.l. 25.05.1995. S. Kurbatov leg. ( MHNG) ; JIANGSU: 1 ♂ : ‘ ♀ ’, ‘ Chinkiang Col. Reitter’, ‘ Nordwestl. ’, ‘ China’ , ‘mutatum Shp. Det. Bernhau [er]’, ‘ Dr. M. Bernhauer 10.XI. donavit 1942’, ‘ex coll. Scheepeltz’ ( NMW) ; JAPAN: REGION NOT LOCATED: 1 ♂ (dissected) : ‘ ♂ ’, ‘ Sharp Coll 1905-313.’, ‘ Olophrum vicinum Sh. co-type’, ‘ Dr. M. Bernhauer 10.XI. donavit 1942’, ‘ex. coll. Scheerpeltz’ , ‘ TYPUS Olophrum mutatum m. O. Scheerpeltz’ ( NMW) .

Description. Measurements (n=4): HW: 0.72–0.75; HL: 0.48–0.52; OL: 0.17; TL: 0.13; AL (holotype): 1.72; PL: 0.72–0.75; PWmax: 1.17–1.20; PWmin: 1.06–1.10; ESL: 1.50–1.67; EW: 1.60–1.62; MTbL (holotype): 0.85; MTrL (holotype): 0.39 (MTrL 1–4: 0.22; MTrL 5: 0.17); AW: 1.48–1.57; AedL: 0.80; BL: 3.85 (holotype)–4.50.

Body moderately wide, with strongly convex pronotum and elytra, and short ( Fig. 2 and Fig. 1J in Kim & Ahn (2015)) or elongate abdomen ( Fig. 1 ). Coloration reddish-brown, with head and abdomen distinctly darker; apical, lateral and basal portions of pronotum, and latero-apical, lateral and medio-apical parts of elytra yellow-brown; antennomeres 4–11 brown; mouthparts and antennomeres 1–3 yellow; legs yellowish. Clypeus without punctures except for mediobasal part with several fine punctures, middle part of head with regular, fine and relatively dense punctation, slightly sparser in lateral portions near eyes, postocular parts with indistinct fine and sparse punctation; neck with fine punctation similar to that in middle portion of head; pronotum with dense pucntation, distinctly larger and deeper than that in middle area of head, sparser in lateral portions and slightly finer and sparser in mediobasal third; scutellum without visible punctures; elytra with dense and large punctation, slightly larger than that on pronotum, but punctation in middle portion around scutellum and along suture distinctly finer, on each elytron forming seven longitudinal vague and tangled rows of punctures; abdominal tergies without punctation. Head with distinct microsculpture: transverse on clypeus, transverse and diagonal in latero-apical portions between antennal insertions and apical margins of eyes, finer in middle, and isodiametric on infraorbital portions; neck with dense transverse meshes; pronotum, scutellum and elytra without microsculpture; abdominal tergites with dense and fine isodiametric microreticulation. Body glabrous; apical part of clypeus with several erect and elongate setae; abdominal tergites with indistinct, very sparse and short setae.

Head 1.4–1.5 times as broad as long, slightly elevated in middle, with indistinct transverse impression in front of ocelli; supra-antennal prominences relatively strongly elevated; postocular ridges obtuse, each with interspace between posterior margin of eye and ridge about as long as diameters of three nearest ommatidia; temples somewhat convex, rounded, from postocular ridges gradually narrowed toward neck, 1.3 times as long as longitudinal length of eyes. Eyes large, convex. Ocelli large, located at level of postocular ridges, distance between ocelli about 1.5 times as long as distance between ocellus and posterior margin of eye. Apical maxillary palpomere about twice as long as preapical segment, from basal portion strongly narrowed toward acute apex. Antenna reaching basal third of elytra when reclined, with distinctly elongate antennomeres 4–7 and slightly elongate 8–10; basal antennomere relatively wide, more than three times as long as broad, antennomere 2 shorter and slightly narrower than basal antennomere, 3 about as long as 2, 4 distinctly shorter than 3, 5–6 slightly longer and broader than 4, 7 indistinctly shorter and broader than 6, 8 shorter than 7, 9–10 indistinctly broader than 8, apical antennomere 1.7 times as long as 10, from apical part strongly narrowed toward subacute apex.

Pronotum evenly convex, 1.6 times as broad as long, 1.6 times as broad as head, widest in or slightly below middle, gradually narrowed both anteriad and posteriad; anterior angles rounded, indistinctly protruded anteriad; posterior angles widely rounded; apical margin rounded, about as long as rounded posterior margin; lateral portions widely impressed, each with oval and deep depression in middle.

Elytra elongate, convex, slightly broader than long, gradually broadened posteriad, distinctly more than twice as long as pronotum, reaching apical margin of abdominal tergite III or IV; surface of each elytron with two indistinct longitudinal elevations between punctures in middle. Hind wings fully developed.

Legs moderately long and slender, with long and dense spines in inner and outer margins of tibiae (stronger in meso- and metatibiae); metatarsi 1.3 times as long as metatibia.

Abdomen convex, slightly narrower than elytra, with a pair of small oval tomentose spots in middle of abdominal tergite V and with narrow indistinct palisade fringe on posterior margin of abdominal tergite VII.

Male. Middle part of protibia slightly swollen. Posterior margin of abdominal tergite VIII slightly and sternite VIII deeply sinuate. Aedeagus short, with very wide basal portion, strongly narrowed toward widely rounded apex; parameres slightly longer than apex of median lobe, each with broadened apical lobes widened toward middle and narrowed apically, with two short apical setae; internal sac wide and long, spirally folded in basal portion, with two slightly sclerotized fields of spines in apical part ( Figs 7–8 ). Lateral aspect of the aedeagus as in Fig. 9 .

Female. See Kim & Ahn (2015).

Comparative notes. Based on the general shape and the length of the body, the markedly convex forebody and similar coloration, O. mutatum is similar to O. vicinum (see below), from which it can be distinguished by the shorter preapical antennomeres 9–10, denser punctation of the pronotum, shape of the pronotum widest in or slightly behind middle, and shape of the slightly shorter and broader aedeagus.

Distribution. Olophrum mutatum is known from Japan (without exact locality), South Korea ( Kim & Ahn 2015), and China (Hubei, Jiangsu). New country record for China.

Bionomics. A specimen from China was collected at an elevation of 500 m. Specimens from South Korea were collected at altitudes from 110–130 m and were found mostly near streams ( Kim & Ahn 2015).

Remarks. Olophrum mutatum was originally described from Japan with an unspecified type locality. It was redescribed by Kim & Ahn (2015) based on the study of material from South Korea. I studied the holotype ( Fig. 2 ) and three specimens from China and Japan. One specimen from Japan has the red type label also and several similar labels as in the holotype (see above). This specimen was donated to NMW in 1942 and does not belong to the type series. One specimen from Hubei ( Fig. 1 ) has an unusually elongate abdomen, but based on the external and the internal morphology it is conspecific to other studied specimens ( Figs 7–9 ).

Figures

FIGURES 1–6. Habitus of Olophrum: 1–O. mutatum (Hubei), 2–O. mutatum (holotype), 3–O. scheerpeltzi (holotype), 4–O. japonicum (holotype), 5–O. simplex (paralectotype), 6–O. vicinum (lectotype). Scale bar: 1.0 mm.

FIGURES 7–9. Aedeagus of Olophrum mutatum (Fig. 7: Hubei; Figs 8–9: holotype): 7–8–parameral view, 9–lateral view. Scale bar: 0.1 mm.