Figs 16–17
Type material. Holotype: adult female. Russia (East Siberia), S Buryat Republic, Zagansky Range, northern slope, near Shibertuy, 813 m alt., 50.82321°N, 107.87671°E, birch forest, 21.viii. 2011, leg. A.Gulgenova & L.Vanyavina. 10 paratypes from the same locality. Holotype and 5 paratypes in MSPU; 5 paratypes in BSU.
Description. Body size about 0,8 mm (for two adult females). Body without pigmentation, of normal shape. Cuticle with thin hexagonal primary granulation. Ocelli absent. PAO, slightly constricted, 1.3–1.6 as long as width of Ant I and 1.5–1.8 as long as inner unguis length. Maxillary outer lobe with 4 sublobal hairs, maxillary palp bifurcate. Labral formula as 4 /5,5,4. Labium with 5 usual papillae (А–Е), guard chaetae e 7 present, proximal, basomedian, and basolatera chaetae as common for the genus. Ventral side of a head with 4–5 + 4–5 chaetae. Ant.I with 2 ventral sensilla (s) and 2 small basal microsensilla (bms), dorsal and ventral, the former set together with a long chaetaceous microsensillum, Ant.II with 3 bms and 1 latero-distal s, Ant.III with 1 bms and with 6 distal s (including 2 lateral), without additional sensilla. Sensilla on Ant. 4 weakly differentiated. Organite stick-form, small.
Sensillary formula as 4,3 /2,2,2,3,5 (s), 1,0/1,0,0 (ms). Tergal sensilla thin, as long as or longer than common chaetae. Medial sensilla on Th.II–Abd.III situated in mid-tergal position, on Abd.I–III between Mac 1 and Mac 2. Abd.V with 5 sensilla arranged with 3 dorsal ones (al, accp 1, accp 2), long and slender, 1 lateral slightly shorter, and 1 ventral, the shortest (Fig. 16). Macrochaetae smooth, 1,1 /3,3,3 in number, medial ones on Abd.V 1.8–2.1 times shorter than dens and 4.5–5.5 times longer than mucro. 7 foil chaetae at the tip of abdomen arranged as 4 anterior (fa 1 and fa 2) and 3 posterior (fp0 and fp 2). Thorax without ventral chaetae.
Unguis of normal shape, without any teeth. Empodial appendage about half as long as unguis (0.45–0.55). Tibiotarsi with additional chaetae on Leg I and II (25–28 in all), and with many on Leg III (> 30 in all). Tibiotarsal tenent chaetae pointed. VT with 4 + 4 (5) laterodistal and 5 posterior chaetae, anteriorly without chaetae. Tenaculum with 4 + 4 teeth and a chaeta. Anterior furcal subcoxae with 8–10, posterior one with 5 chaetae. Anterior side of manubrium with 5–6 + 5–6 (4) paired chaetae and 1–2 unpaired in proximal part, arranged as: 3 + 3,1 + 1,1 + 1,1; 3 + 3,1 + 1,1 + 1,1 + 1,1; 3 + 3,1 + 1,1 + 1,2 (Fig. 17). Posterior side of manubrium with at least 4 + 4 laterobasal, 2 apical chaetae (ap), 3 + 3 chaetae in distal transversal row (M 1, ml 1, L 1), two pairs of lateral chaetae (l 1, l 2), and 6 + 6 in central part. Dens with 25–28 anterior chaetae (Fig. 17). Posterior side of dens crenulated at the middle and with 6 normal chaetae (4 basal and 2 at the middle) and one rudimentary minute chaeta at the base of mucro (Fig. 17). Mucro bidentate. Ratio of manubrium:dens:mucro = 4.9–5.9: 8.9–9.6: 1.
Discussion. F. maximovi sp. nov. and F. culter share many characters including the chaetotaxy of furca, shape of foil chaetae, sensillar chaetotaxy, and morphology of outer mouth parts. Two notable differences between the two species are ventral chaetae on Th.III (absent in F. maximovi sp. nov., present in F. culter) and shape of accp 3 and accp 4 sensilla on Abd.V (accp 3> accp 4 in F. maximovi sp. nov., accp 3 = accp 4 in F. culter).
Distribution and ecology. Known from three localities in the Zagansky Range (S Buryatia) (Fig. 1: loc. 3).
Etymology. In memory of Victor Maximov, a founder of General Ecology department of Moscow State University, who worked on theory of analysis of communities, among this the use of a similarity standard for comparing the springtail populations.