Olophrum simplex Sharp, 1874

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 : 100-101

Olophrum simplex Sharp, 1874

( Figs 4–5 , 12–15 )

Olophrum simplex Sharp, 1874: 97 ; Scheerpeltz 1929: 108, Watanabe 1990: 139, <?!> Li 1993: 19.

Olophrum japonicum Scheerpeltz, 1929: 110 syn. n.

Olophrum japonicum : Watanabe 1990: 137.

Olophrum kawasei Hayashi, 2020: 331 syn. n.

Type material examined. Lectotype (here designated) of O. simplex Sharp, 1874 ♂ ( Fig. 5 ; the specimen glued on the same card with female): ‘ SYN- |TYPE’ <round printed label with blue margin>, ‘ Japan. [underlined by yellow] | G. Lewis.’ <printed>, ‘Sharp Coll | 1905-313.’ <printed>, ‘ Syntype | Olophrum | simplex | Sharp, 1874 | det. R.G.Booth 2007 [printed]’ <handwritten>, ‘NHMUK015011178’ <printed, with barcode on the right side of the label>, ‘NHMUK015011179’ <printed, with barcode on the right side of the label>, ‘LECTOTYPE’ <red, printed>, ‘ Olophrum | simplex Sharp, 1874 | Shavrin A.V. det. 2025’ <printed> ( BMNH).

Paralectotypes: 1 ♀ (glued dorsally together with the lectotype): labels as above ( BMNH); 1 ♀ [handwritten text under the glued on the card specimen: ‘ Olophrum | simplex | Yokohama | 10.3.1880. | G. Lewis.’]: ‘ SYN- |TYPE’ <round printed label with blue margin>, ‘Sharp Coll. | 1905-313.’ <printed>, ‘Photographiert | 2-12.XI.1928 [handwritten] | O. Scheerpeltz’ <pink, printed>, ‘simplex | Sharp’ <handwritten>, NHMUK015011177’ <printed, with barcode on the right side of the label> ( BMNH); 1 ♀ (left antennomeres 8–11 and 3–11 missing): ‘ ♀ ’ <printed>, ‘Sharp Coll | 1905-313.’ <printed>, ‘ Japan. [underlined by yellow] | G. Lewis’ <printed>, ‘ex | Coll. British | Mus. Nat. Hist.’ <handwritten>, ‘Dr. G.J. Arrow | donavit.’ <handwritten>, ‘ Olophrum | simplex, | co-type Shp.’ <handwritten>, ‘ex coll. | Scheerpeltz’ <blue, printed>, ‘COTYPUS [printed] | Olophrum | simplex | Sharp | teste: Arrow’ <pink, handwritten> ( NMW); 1 ♀ (both antennomeres 3–11, left tibia and tarsus, and right first leg missing): ‘ ♀ ’ <printed>, ‘ Japan. [underlined by red] | G. Lewis.’ <handwritten>, ‘Sharp-Coll. | 1905-313.’ <handwritten>, ‘ex | Coll. British | Mus. Nat. Hist.’ <handwritten>, ‘Dr. G.J. Arrow | donavit.’ <handwritten>, ‘Dr. G.J. Arrow | donavit.’ <handwritten>, ‘ex coll. | Scheerpeltz’ <blue, printed>, ‘COTYPUS [printed] | Olophrum | simplex | Sharp | teste: Arrow’ <pink, handwritten> ( NMW). All paralectotypes with additional printed label: ‘ Olophrum | simplex Sharp, 1874 | Shavrin A.V. det. 2025’.

Holotype of O. japonicum Scheerpeltz, 1929 ♂ ( Fig. 4 ; dissected): JAPAN: HONSHU: ‘ ♂ ’ <printed>, ‘Japonia | Kioto. DonKier’ <handwritten>, ‘simplex Shp. [handwritten] | det. Bernh.’ <printed>, ‘Photographiert | 9-17.XI.1928 [handwritten] | O. Scheerpeltz’ <pink, printed>, ‘Dr. M. Bernhauer | 10.XI [handwritten] donavit 1942 [handwritten]’ <printed>, ‘ex. coll. | Scheerpeltz’ <blue, printed>, ‘TYPUS | Olophrum [handwritten] | japonicum m. [handwritten] | O. Scheerpeltz’ <red, printed>, ‘ Olophrum | japonicum Scheerpeltz, 1929 | Shavrin A.V. det. 2025’ ( NMW).

Additional material examined. JAPAN: HOKKAIDO: 1 ♀: Nopporo Shinrin Koen, Ebetsu-shi. 20.10.2007. T. Lackner leg. (cSh); HONSHU : 1 ♂: Ibaraki Prefecture, environs of Tsukuba. 04.2007. P. Jałoszyńsky leg. (cSh) ; 1 ♀: Nikko, N.P. Ryuzu . 16.07.1980. 1400 m a.s.l. A. Smetana & Z. Smetana leg. ( CNC) ; 1 ♂: Kioto ( NMW) ; 1 ♂: Takahama. 16.06.1950. Ueno leg. ( NMW) ; 1 ♀: Nara Prefecture, Mt. Kasuga. 14.04.1951. don. Y. Wada ( NMW) ; 1 ♂: Hyôgo Prefecture, Takarazuka. 14.04.1949. don. Y. Wada ( NMW) .

Redescription. Measurements (n=12): HW: 0.60–0.67; HL: 0.40–0.45; OL: 0.14–0.17; TL: 0.10–0.12; AL (lectotype of O. simplex ): 0.00; PL: 0.61–0.69; PWmax: 0.91–1.09; PWmin: 0.81–0.98; ESL: 1.15–1.47; EW: 1.40– 1.56; MTbL (lectotype of O. simplex ): 0.87; MTrL (lectotype of O. simplex ): 0.47 (MTrL 1–4: 0.25; MTrL 5: 0.22); AW: 1.30–1.37; AedL: 0.65–0.67; BL: 2.96–4.55 (lectotype of O. simplex : 3.25; holotype of O. japonicum : 3.72).

Body relatively wide, with slightly convex pronotum and elytra ( Figs 4–5 ). Coloration yellow-brown to reddish-brown, with darker head and abdomen; antennomeres 3–11 or 4–11 brownish; mouthparts, antennomeres 1–2 or 1–3 and legs yellow-brown, sometimes with paler tarsi. Head with sparse and fine punctation, usually denser in middle and on infraorbital portions, but some specimens with extremely sparse punctation in middle; neck with fine and sparse punctation; pronotum with moderately dense punctation, distinctly larger and deeper than that on head, finer and sparser in mediobasal portion; scutellum without or with several fine punctures; elytra with dense punctation, slightly larger and deeper than that on pronotum, denser and deeper around scutellum and usually finer along suture, each elytron sometimes forming indistinct six to seven vague and tangeled rows of punctures, but some specimens without these rows. Head with dense microsculpture: transverse on clypeus and isodiametric in middle and on infraorbital portions; neck with dense isodiametric microreticualtion; pronotum with dense transverse or isodiametric microsculpture, sometimes indistinct or missing in mediobasal third; scutellum and elytra without meshes; abdominal tergites with dense isodiametric sculpture.

Head 1.4–1.5 times as broad as long, sometimes with indistinct transverse impression in front of ocelli; postocular ridges indistinct, obtuse, each with interspace between posterior margin of eye and ridge about as long as diameters of two-three nearest ommatidia; temples distinctly broadened, 1.4 times as long as longitudinal length of eyes. Ocelli located about at level of postocular ridges, distance between ocelli slightly longer than distance between ocellus and posterior margin of eyes. Antenna with elongate antennomeres 4–6 and somewhat shortened 7–10; antennomere 3 slightly longer than 2, 4 shorter than 3, 5–6 slightly longer and broader than 4, 7–10 distinctly shorter than 6, apical antennomere about 1.5–1.6 times as long as 10.

Pronotum slightly convex, 1.4–1.5 times as broad as long, 1.5–1.6 times as broad as head, widest in or slightly in front of middle, gradually or slightly more narrowed posteriad than anteriad; anterior angles slightly or distinctly protruded anteriad; apical margin rounded, slighly shorter than straight or rounded posrerior margin; each widely impressed lateral portion with deep oval depression in or about middle.

Elytra short, broader than long and gradually broadened posteriad, about twice as long as pronotum or longer, reaching apical margin of abdominal tergite III or IV; surface of each elytron without or with elongate and transverse elevations between punctures.

Metatarsi 1.8 times as long as metatibia.

Abdomen narrower than elytra, with a pair of indistinct small oval or transverse tomentose spots in middle of abdominal tergite V.

Male. Posterior margin of abdominal tergite VIII truncate or slightly sinuate. Posterior margin of abdominal sternite VIII slightly or deeply sinuate. Aedeagus short, from broadest basal portion slightly narrowed toward widely rounded or truncate apex; parameres slightly longer than apex of median lobe, each with slightly or widely broadened apical lobes, from widest middle narrowed toward rounded apex, with two short apical setae; internal sac long, broadened part spirally folded in basal portion, median and apical part with two narrow fields with small spines separated each other apically ( Figs 12, 14 ). Lateral aspect of aedeagus as in Figs 13, 15 .

Female. Posterior margins of abdominal tergite VIII and sternite VIII truncate.

Comparative notes. Based on the general shape of the slightly convex forebody and the shape of the pronotum widest near the middle, O. simplex is similar to the Japanese O. tadashii Watanabe, 1990 , from which it can be distinguished by paler coloration, slightly narrower antennomeres 7–10, slightly sparser punctation on head and pronotum, slightly more transverse pronotum, shorter elytra, lack of a subtriangular tooth in the middle of inner margin of protibia in males, and details of the morphology of the aedeagus.

Distribution. Olophrum simplex is known only from Japan (Hokkaido, Honshu, Kyushu). New record for Hokkaido.

Bionomics. One specimen from Honshu was collected at an elevation of 1400 m a.s.l. by sifting of forest litter. The type specimens of O. kawasei were collected “…by sifting the leaf litter accumulated in the road-side ditch at the edge of the deciduous broadleaved forest” ( Hayashi 2020).

Remarks. Olophrum simplex was originally described from Japan based on an unspecified number of syntypes. I studied three syntypes from BMNH and two from NMW respectively. One male from BMNH I designated here as a lectotype. Scheerpeltz (1929) redescribed O. simplex , but did not provide an illustration of the aedeagus. Watanabe (1990) did not redescribe this species, but included it in the key of Olophrum of Japan, and provided the distribution of the species as “ Japan (Honshu, Kyushu)”.

Olophrum japonicum was originally described from “Japonia, Kioto …” based on the holotype. Watanabe (1990) redescribed it, provided figures of the aedeagus and recorded it from Honshu. During the study of types of O. simplex and O. japonicum ( Fig. 4 ), I could not find significant morphological differences between them ( Figs 4–5 , 12–15 ). Thus, I synonymized O. japonicum with O. simplex .

Olophrum kawasei was originally described from Ishikawa Prefecture (Honshu) based on the study of several specimens. Based on the original description, the habitus ( Fig. 1 in Hayashi (2020)) and the morphology of the aedeagus ( Figs 3–4 in Hayashi (2020)), O. kawasei is conspecific with other specimens of O. simplex and the type of O. japonicum . Thus, I synonymized it with O. simplex .

The record of O. simplex from north-western China ( Li 1993) seems to be erroneous and requires confirmation.

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 10–15. Aedeagus of Olophrum (Figs 10–11: O. scheerpeltzi (holotype); Figs 12–13: O. simplex (Japan: Sapporo); Figs 14–15: O. japonicum (holotype)): 10, 12, 14–parameral view, 11, 13, 15–lateral view. Scale bar: 0.1 mm.