Omalium muensteri Bernhauer, 1901

Omalium muensteri Bernhauer, 1901 View in CoL

( Figs 1 View FIGURES 1–4 , 5–8)

Omalium muensteri Bernhauer, 1901: 540 View in CoL ; Luze 1906: 542; Palm 1948: 82.

Omalium ( Omalium) muensteri View in CoL ; Bernhauer & Schubert 1910: 55.

Type material examined. Lectotype ( here designated) ♂: NORWAY: ‘Kristiania. | Münster’ <printed>, ‘Münsteri Brh | Norwegen | Type.’ <handwritten in black>, ‘Fauvel | vidit’ <light green, handwritten in black>, ‘Chicago NHMus | M.Bernhauer | Collection’ <printed>, ‘ SYNTYPE | teste D.J.Clarke2014 | GDI Imaging Project’ <violet, printed>, ‘ Lectotype | Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <red, printed>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( FMNH).

Paralectotypes: NORWAY: 1 ♀: ‘Kristiania. | Münster’ <printed>, ‘Münsteri Brh | Norwegen | Type.’ <handwritten in black>, ‘Chicago NHMus | M.Bernhauer | Collection’ <printed>, ‘Münsteri Bernh. | Verh. z. b. Ges. 1908, | p. 540’ <large rectangular handwritten label, with black margins>, ‘ SYNTYPE | teste D.J.Clarke2014 | GDI Imaging Project’ <violet, printed>, ‘PHOTOGRAPHED | Kelsey Keaton 2014 | Emu Catalog’ <blue, printed>, ‘FMNHINS | 2819649 | FIELD MUSEUM’ <printed, with barcode on the left side of the label> ( FMNH); 1 ♂ (dissected): ‘Kristiania. | Münster’ <printed>, ‘Münsteri Brh | Norwegen | Type.’ <handwritten in black>, ‘Chicago NHMus | M.Bernhauer | Collection’ <printed>, ‘ SYNTYPE | teste D.J.Clarke2014 | GDI Imaging Project’ <violet, printed> ( FMNH); 2 ♀♀ ( one specimen dissected): first two labels as the previous, ‘CNHM 1955 | Eduard Knirsch | Palaearctic Colln.’ <printed> ( FMNH); 1 ♂: ‘ ♂ ’ <printed>, ‘Kristiania | Münster’ <printed>, ‘münsteri | Bnh. Type’ <handwritten>, ‘vidit Luze’ <printed>, ‘ex. coll. | Skalitzky’ <green, printed>, ‘TYPUS [printed] | Omalium | Münsteri | Bernh.’ <printed>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( NMW); 2 ♀♀: ‘ ♀ ’ <printed>, 2 nd and 3 rd labels as the previous, ‘Type’ <blue, handwritten>, ‘vidit | Luze’ <printed>, ‘ex. coll. | Skalitzky’ <green, printed>, ‘TYPUS [printed] | Omalium | Münsteri | Bernh.’ <printed>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( NMW); 2 ♂♂: ‘ ♂ ’ <printed>, ‘Kristiania’ <printed>, ‘Münster’ <printed>, ‘Münsteri Bnh. | Norwegen | Type’ <handwritten>, ‘ex. coll. | Luze’ <yellow, printed>, ‘TYPUS [printed] | Omalium | Münsteri | Bernh.’ <printed>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( NMW); 1 ♂ (right antennomeres 3–11 missing): first three labels as the previous, ‘coll. Schuster’ <violet, printed>, ‘TYPUS [printed] | Omalium | Münsteri | Bernh.’ <printed>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( NMW); 1 ♂: first three labels as the previous, ‘O. Mün | steri’ <handwritten>, ‘vidit | Luze’ <printed>, ‘ex. coll. Skalitzky’ <green, printed>, ‘ex. coll. | Scheerpeltz’ <blue, printed>, ‘COTYPUS [printed] | Omalium | Münsteri | Bernh.’ <pink, handwritten>, ‘Umg. Kristiania | Norwegen’ <handwritten>, ‘ Omalium | Münsteri’ <green, handwritten>, ‘ Omalium | muensteri Bernhauer, 1901 | Shavrin A.V. det. 2025’ <printed> ( NMW).

Additional material examined. NORWAY: 1 ♀: ‘Kristiania Münster’, ‘Collect. Hauser’, ‘ Omalium münsteri Bernh.’ ( NMW); 1 ♀: ‘Kristiania Münster’, ‘ Omalium Münsteri’, ‘Muensteri Bernh. det. Luze’ ( NMW); 1 ♂: ‘Kristiania Münster’, ‘Münsteri’, ‘Muensteri Bernh. det. Luze’ ( NMW); 1 ♂: ‘Kr[istia].nia’, ‘ Omalium longicorne mihi n. sp.’, ‘Münster Norv. longicorne’, ‘Muensteri Bernh. det. Luze’ ( NMW); 1 ♂: ‘Münster Norv. longicorne’, ‘Muensteri Bernh. det. Luze’ ( NMW); 1 ♀: ‘[illegible] Münster IV/06’, ‘Kristiania Ths Münster’, ‘Münsteri det. Münster’, ‘ Omalium Münsteri’ ( NMW); SWEDEN: 1 ♀: ‘Up[psala]. Rasbo. Tomta 18.3.1990 leg. Ǻ. Lindelöw’, ‘muensteri det. S. Lundberg’ ( NMW).

Redescription. Measurements (n=15): HW: 0.62–0.80; HL: 0.40–0.47; OL: 0.15–0.20; TL: 0.07–0.10; AL ( lectotype): 1.32; PL: 0.50–0.59; PWmax: 0.77–0.87; PWmin: 0.68–0.75; ESL: 0.90–0.99; EW: 1.04–1.22; MTbL ( lectotype): 0.55; MTrL ( lectotype): 0.25 (MTrL 1–4: 0.10; MTrL 5: 0.15); AW: 1.02–1.37; AedL: 0.82; BL: 3.25– 4.20 ( lectotype: 3.45).

Habitus as in Fig. 1 View FIGURES 1–4 . Body reddish-brown, with slightly darker head and abdomen; mouthparts, antennae and legs yellow-brown (antennomeres 6–11 slightly paler). Punctation of head irregular, finer and sparser on frontal part of clypeus, sometimes denser, larger and deeper in middle; neck with moderately regular, fine and relatively dense punctation; punctation of pronotum dense, slightly larger and deeper than that in middle part of head, sparser in lateral and mediobasal portions, usually finer in middle and mediobasal third; scutellum without punctures; punctation of elytra dense, about as that on pronotum, sometimes finer around scutellum and slightly sparser in middle; abdominal tergites without distinct punctation. Anterior half of clypeus with dense and transverse microsculpture, laterobasal parts of clypeus with dense diagonal and sometimes strong meshes, middle part with fine and sometimes indistinct transverse microreticulation, infraorbital portions with irregular longitudinal and diagonal meshes, stronger near margins of eyes; neck with indistinct and fine transverse meshes, usually invisible in middle; medioapical portion of pronotum sometimes with traces of indistinct microsculpture; scutellum and elytra without microreticulation; abdominal tergites with dense and coarse isodiametric microsculpture. Anterior part of clypeus with several erect elongate setae, each laterobasal parts of clypeus sometimes with additional long seta; lateral margins of pronotum and elytra with sparse and very short setae; abdomen with sparse and short adjoining setation; anterior and posterior margins of pronotum with indistinct fine and short cuticular fringe.

Head 1.5–1.7 times as broad as long, with slightly or relatively strongly elevated middle and infraorbital portions; clypeus broad and explanate, with posteriolateral margins gradually rounded posteriad and reaching level of middle or posterior third of eyes; supra-antennal elevations strongly elevated and explanate; anteriomedian depressions deep and wide, reaching level of anterior third of eyes. Middle part with irregular transverse and diagonal elevations between punctures, mediodorsal margins of infraorbital portions near margins of eyes with longitudinal fine elongate wrinkles. Anteocellar foveae deep, sublinear or slightly convergent latero-apicad toward level of about middle of eyes. Temples about twice as long as longitudinal length of eyes, from posterior margins of eyes strongly narrowed toward neck. Nuchal constriction relatively wide and deep. Eyes moderately large and convex. Ocelli large, located distinctly behind level of posterior margins of eyes; distance between ocelli short, about twice as long as distance between ocellus and posterior margin of eye. Maxillary palpi moderately long, apical palpomere about four times as long as penultimate segment, from widest middle gradually narrowed toward subacute apex. Antenna reaching basal margin of elytra when reclined, with distinctly elongate antennomeres 5–10; basal antennomere wide, about three times as long as broad, antennomere 2 about twice shorter and distinctly narrower than basal antennomere, 3 slightly longer and narrower than 2, 4–5 distinctly shorter than 3, 6 slightly longer and broader than 5, 7 slightly broader than 6, 8 indistinctly broader than 7, 9–10 slightly broader than 8, apical antennomere 1.3 times as long preapical antennomere, from apical third strongly narrowed toward subacute apex.

Pronotum 1.4–1.5 times as broad as long, 1.1–1.2 times as broad as head, from widest middle distinctly more narrowed posteriad than anteriad, anterior angles widely rounded, not protruded anteriad, laterobasal margins indistinctly concave in front of obtuse hind angles. Lateral portions relatively narrowly impressed, each in about middle with wide elongate impressions. Surface of disc with two elongate, shallow or moderately deep longitudinal depressions, slightly broadened basad, without or with indistinct shallow and narrow medioapical depression; each lateroapical portion with indistinct, narrow and widely curved elevations, reaching about middle of pronotum; median surface between all pronotal depressions slightly elevated; middle portion sometimes with fine irregular transverse or diagonal elevations between punctures.

Elytra slightly broader than long, 1.6–1.8 times as long as pronotum, slightly broadened posteriad; lateral portions narrowly impressed and slightly explanate; hind margins somewhat straight. Dorsal surface of each elytron with strong irregular diagonal and longitudinal elevations between punctures, stronger in medioapical half. Hind wings fully developed.

Metatarsi more than twice shorter than metatibia.

Abdomen convex, slightly narrow or broader than elytra, with two small round wing-folding patches in middle of abdominal tergite IV and narrow palisade fringe on posterior margin of tergite VII.

Male. Posterior margin of abdominal tergite VIII straight. Posterior margin of abdominal sternite VIII widely concave. Aedeagus with relatively broad basal part, slightly narrowed toward wide and elongate median lobe; median lobe from preapical part gradually narrowed toward widely rounded apex, with distinct apical excision; median portion with short and narrow slightly sclerotized accessory plates, curved latero-apicad, each rounded apically; parameres short, reaching middle half of median lobe, with distinctly narrowed preapical third, with one long and three short apical setae; internal sac wide and long, with field of large spines in apical part (Fig. 5). Lateral aspect of the aedeagus as in Fig. 6; apical portion of median lobe somewhat broadened, with rounded apex, slightly crenulated ventroapically, with distinct rounded tooth in about middle.

Female. Posterior margin of abdominal tergite VIII truncate. Posterior margin of abdominal sternite VIII truncate or slightly concave. Accessory sclerite with wide basal part and narrow elongate apical portion (Fig. 7). Spermatheca as in Fig. 8.

Comparative notes. Based on the body length and the coloration, and the general shape of the aedeagus, O. muensteri is similar to the East Palaearctic O. longicorne Luze, 1906 , known from north-eastern Mongolia and eastern Siberia ( Shavrin 2025b). It can be distinguished from O. longicorne by the larger, denser and coarser punctation of the forebody, slightly broader pronotum, shorter elytra, distinctly broader and longer median lobe of the aedeagus, shorter parameres with narrower preapical portions, different shape of the female accessory sclerite, and other details of the morphology of the aedeagus.

Distribution. The Fennoscandian O. muensteri is known from several localities in Norway, Sweden and Finland.

Bionomics. Some specimens were collected in mosses ( Palm & Lundberg 1993, Lundberg 2001), marshy bank of river ( Palm & Lundberg 1993) or in organic remains near river ( Strand 1969).

Remarks. Omalium muensteri was originally described based on an unspecified number of syntypes (“mehreren Stücken”) from “…Kongsberg in der Umgebung von Christiania in Norwegen ”. I have studied 12 syntypes from FMNH and NMW, and one male from FMNH was designated as the lectotype in order to fix the identity of the name. This species is rarely found in collections. There are only several records from Norway ( Bernhauer 1901; Lysholm 1912; Munster 1923; Strand 1969), Sweden ( Lundberg 1984, 2001; Palm & Lundberg 1993), and Finland (Krogerus 1972). It was included in the Norwegian Red List ( Ødegaard et al. 2015). Records for Caucasus and Caspian region are doubtful ( Herman 2001). Luze (1906) redescribed it. Palm (1948) included O. muensteri in the key of rove beetles of Sweden. Despite this, no illustrations were provided for this species, including the aedeagus. Thus, I redescribed and illustrated it herein.