Micrambe Thomson, 1863

Genus Micrambe Thomson, 1863

Subgenus Neomicrambe Otero & Pereira, 2019

Micrambe (Neomicrambe) danica Lyubarsky et Perkovsky sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:BE047AEC-5E77-4528-9128-99F76CCF09C7

Type material. Holotype. NHMD-153495, hand-written label ‘ Clavicornia G. V. Hennigsen / 1-8 1962 ’ Danish amber, late Eocene.

Etymology. The specific epithet is a toponym formed from Denmark.

Differential diagnosis. Micrambe danica sp. nov. differs from M. tristis Lyubarsky et Perkovsky, 2024 (Danish amber) by body length ( M. danica significantly less, less than 1.6 mm, M. tristis - 1.8 mm); callosity occupying about one-third of pronotum side margin ( M. tristis : one-fifth of side margin); antennomere 4–8 elongate, 1.5x as long as wide ( M. tristis : antennomere 4–8 subquadrate); antennomere 7 slightly longer than 6 and 8 ( M. tristis : antennomere 7 approximately equal length to antennomere 6 and 8); pronotum stronger transverse, 0.55 times as long as wide ( M. tristis : 0.75 times as long as wide); elytra convex on the sides ( M. tristis : elytra almost parallel-sided).

Description. Body length 1.65 mm, maximal body length 0.8 mm, pronotum length 0.4 mm, pronotum width 0.68 mm, elytra length 1.05 mm, elytra width 0.78 mm. Body broadly elongate ( Figure 1A View Figure 1 ), slightly convex; head, pronotum, and elytra reddish brown. Elytra slightly convex, covered with almost appressed pubescence ( Figs 1A View Figure 1 , 3A View Figure 3 ). Head transverse, of normal size, with prominent, hemispherical, somewhat coarsely facetted eyes ( Figs 1A, 1B View Figure 1 , 3B View Figure 3 ), head strongly and densely punctured (1 diameter apart). Antennae 11-segmented, long, slender, with 3-segmented club, club reaches beyond the base of pronotum ( Figs 3A, 3B View Figure 3 ), antennomeres 1–2 elongate, 1.5x as long as wide ( Figs 1A,B View Figure 1 , 2A View Figure 2 ), antennomere 3 slender, 2x as long as wide, equal to 2nd in length, antennomere 4th slender, 1.5x as long as wide, antennomere 3 in 1.5x as long as 4th length, antennomere 5 1.5x as long as wide, antennomere 6 1.6x as long as wide, antennomere 7 1.85x as long as wide, antennomere 8 1.4x as long as wide, 6th longer than 8th, antennomere 7 slightly longer than 6, antennomeres 9 and 10 transverse, antennomere 11 obliquely oval, antennomeres 11 slightly narrower than 10, in 1.5x as long as 10 ( Figs 1B View Figure 1 , 3B View Figure 3 ).

Pronotum distinctly transverse ( Figure 1A View Figure 1 ), 0.55 times as long as wide, moderately strong, densely punctured (1 diameter apart, an individual puncture almost equal to facet diameter). Pronotum without sublateral line, somewhat convex, weakly crenulate. Anterior angles of pronotum with callosity, callosity occupying about one-third of side margin, with small, elongate-oval patch of bare surface visible from above; caudolateral corner obtuse, without tip. Lateral edge with 3 small teeth basally ( Figure 1C View Figure 1 ). Sides finely margined ( Figs 1C View Figure 1 , 2B View Figure 2 ), narrowed posteriorly, not narrowed anteriorly, anterior edge weakly sinuate. Posterior edge slightly sinuate, posterior corners obtuse, basal groove narrow. Scutellum small, transverse. Tibia slender, without spurs ( Figure 2A View Figure 2 ). Tarsal formula 5-5-4.

Elytra oval, punctuation confused ( Figs 1A View Figure 1 , 2A View Figure 2 ), humeral corners rounded ( Figure 2B View Figure 2 ), shoulders a little broader than maximum breadth of pronotum, 0.74 times as long as wide and 2.6 times as long as thorax, moderately convex, with convex sides and broadly rounded apex, puncturation as strong as, yet more sparse than those on pronotum ( Figs 2A View Figure 2 , 3A View Figure 3 ). Sutural stria present ( Figs 1A, 1C View Figure 1 , 3A View Figure 3 ). Epipleura reduced, present beyond level of posterior margin of 1st ventrite. Ventrite 1 longer than remaining ventrites ( Figure 1B View Figure 1 ).

Remarks. The specimen is probably male (tarsi 5-5-4). Micrambe danica sp. nov. is the second species of the genus reported from Danish amber and the third from European amber. Micrambe sarnensis has been reported from both Rovno amber and Baltic amber ( Lyubarsky & Perkovsky 2010, 2021), and Micrambe tristis from Danish amber ( Lyubarsky et al. 2024a).