Ramussia lovtsovae Kurbatov, 2022

Kurbatov, S. A., 2022, Notes on Pselaphinae (Coleoptera: Staphylinidae) of the Sakhalin Region, Russia, Russian Entomological Journal 31 (1), pp. 36-41 : 39

Ramussia lovtsovae Kurbatov , sp.n.

Figs 1, 3–4, 6, 9, 12–13 , 15–16, 23.

MATERIAL. Holotype ♂: SW Sakhalin, 14 km East of Nevelsk , 46°44´33.8´´N 142°03´04.5´´E, rotten Picea , 22.07.2021, S. Kurbatov ( ZIN) . Paratypes: 6♂ with holotype (1 specimen is dismembered) (( MHNG, ZIN, ZMUM, PCSK).

DESCRIPTION. Body 1.25–1.35 mm long, light brown, in fairly fine, dense decumbent pubescence.

Head 0.19–0.20 mm long, 0.26–0.27 mm wide. Vertexal foveae quite large, distance between them slightly greater than distance from edge of fovea to inner edge of eye at this level. Frontal sulcus rather V-shaped. Anterior edge of the front rounded. Eyes large, convex, their diameter in lateral view slightly longer than length of temples. Temples widely rounded. Head in anterior half with fine punctures except smooth antennal tubercles weakly protruding, rest of the head without pronounced punctation. Antennae ( Fig. 9 ) about the same as the previous species, but antennomeres 9 and 10 can be more than twice or less than twice as wide as length.

Pronotum more or less as long as wide (0.29/ 0.30 mm), widest at its anterior third. Median longitudinal sulcus always present, not connected to the median antebasal fovea. No sulcus present anteriorly of lateral fovea. Punctation very indistinct.

Elytra (0.37–0.40/ 0.43–0.44 mm) with two basal foveae; discal stria not reaching elytral mid-length.

Male secondary sexual characters on head and legs not expressed. Sternite 6 (VIII) emarginate at apex, notch covered by penial plate (IX sternite) 0.115 –0.120 mm long ( Fig. 23 ).

Aedeagus ( Figs 15–16 ) 0.200 – 0.215 mm long.

ETYMOLOGY. This species is named in honor of my collegue Yulia Lovtsova, specialist on Psychidae , who provided valuable assistance to the author during the field work on Sakhalin.

COMMENTS. The new species (as well as the following R. svetlanae sp.n.) differs first of all from R. parabile and R. captiosum sp.n. in the presence of only two basal elytral foveae; in addition, R. parabile lacks the median longitudinal sulcus, which present in R. lovtsovae sp.n.. However, in my opinion, at the present level of knowledge of the group, this is not a sufficient basis to consider them as members of different genera. First, while having three basal elytral foveae R. captiosum sp.n. has also median longitudinal sulcus (though weakly expressed) in some specimens. Second, almost all other characters of the genus level coincide in R. parabile and R. lovtsovae sp.n., including the structure of some previously unexplored mouthparts [see Figs 1–14 and Kurbatov, 1991, P.94–95]. Some difference in the general structure of the aedeagus of R. captiosum sp.n. and R. svetlanae sp.n. on the one hand and R. parabile on the other hand is compensated by the “intermediate” structure of the aedeagus of R. lovtsovae sp.n.. In this situation, I prefer to modify the diagnosis of the genus, taking into account the variability of the abovementioned features (see below).

It is also interesting to mention that all (except one) specimens of R. captiosum sp.n. and R. lovtsovae sp.n. were collected together in the same fragment of a rotten trunk of Picea ajanensis exposed to the sun.

Figures

Figs 1–14. Details of the Ramussia spp: 2, 5, 7–8, 10–11, 14 — R. parabile; 1, 3–4, 6, 9, 12–13 — R. lovtsovae sp.n.; 1–2 — mandibles; 3, 8 — labrum; 4–5 — maxillary palpi; 6–7 — mentum with labial palpi; 9–10 — antennae; 11–12 — profemora; 13–14 — metaventrite. Рис. 1–14. Детали строениЯ Ramussia spp: 2, 5, 7–8, 10–11, 14 — R. parabile; 1, 3–4, 6, 9, 12–13 — R. lovtsovae sp.n.; 1–2 — мандибулы; 3, 8 — верхнЯЯ губа; 4–5 — нижнечелюстные Щупики; 6–7 — подбородок с нижнегубными Щупиками; 9–10 — антенны; 11–12 — передние бёдра; 13–14 — метавентрит.

Figs 15–26. Details of the Ramussia spp: 15–16, 23 — R. lovtsovae sp.n.; 17–18, 24 — R. svetlanae sp.n.; 19–20, 25 — R. parabile; 21–22, 26 — R. captiosum sp.n.; 15–22 — aedeagi, dorsally and laterally; 23–26 — IX sternite. Рис. 15–26. Детали строениЯ Ramussia spp: 15–16, 23 — R. lovtsovae sp.n.; 17–18, 24 — R. svetlanae sp.n.; 19–20, 25 — R. parabile; 21–22, 26 — R. captiosum sp.n.; 15–22 — Эдеагусы, дорсально и латерально; 23–26 — IX стернит.