Vertagopus laricis Martynova 1975

Vertagopus laricis Martynova, 1975

Figs 23, 28

Material examined. Russia: Buryat Republic: NW Buryatia, Barguzinsky Range, ca. 5 km W Barguzin, middle flow of Gremyachaya Brook, 500–900 m alt., forest belt, mosses on stones and trunks, ibidem, upper flow of Bol'shoi Chevyrkuy River, mountain tundra and lichen wasteland after fire, ca. 1750 m alt., 17–20.viii.2008, coll. M.P. and A.G.; NW Buryatia, SE shore of Baikal Lake, at Ust'-Barguzin, dry pine forest on dunes, litter, 5.viii.2014, coll. M.P.; NW Buryatia, NW shore of Baikal Lake, ca. 30 км N Severobaikalsk, nearby Slyudyanskoye Lake, stony steppe on steep SE slope, vegetation in crevices of rocks, ca. 700 m alt., ibidem, dry pine forest with Vaccinium vitis-idae, ca. 700 m alt., litter and moss on stones, 19.viii.2013, coll. M.P. and A.G.; S Buryat Republic, nearby Gusinoozersk, dry grassy pine forest with Fabaceae, litter, 1.viii.2014, coll. M.P.; S Buryat Republic, Zagansky Range, eastern slope, 50.92895°N, 107.91876°E, 1074 m alt., dry pine forest with Vaccinium vitis-idae, sand soil, 21.viii.2011, coll. A.G. and L.V.; S Buryat Republic, Bichurinsky District, Khilokskaya Basin, nearby Shibertuy, mossy spruce wood surrounded by steppe, 50.79364°N, 107.87653°E, 725 m alt., 20.viii.2011, coll. A.G. and L.V.; S Buryat Republic, Dzidinsky District, nearby Borgoi, birch forest in depression, litter, 1.viii.2014, coll. M.P.

Russia: East Siberia: Zabaikal'sky Krai: Alkhanai National Park, valley of Ilya River, nearby Ara-Ilya Station, slope of Mogotuyski Range, 50.926033°N, 113.226467°E, 930 m alt., dry lichen-mossy larch and pine woods with Rhododendron, Vaccinium vitis-idaea, 7.vii.2014, coll. A.G.

Russia: East Siberia: Irkutskaya Region: Bratsk (Gidrostroitel' area), dry pine forest (V. vitis-idaea, moss, Rosa), litter, 14.viii.2013, coll. M.P.; W shore of Baikal Lake, Peschanaya Bay, lichens on stony place, 6.vii.1963, coll. S.Stebaeva.

Russia: East Siberia: the Republic of Tuva: Sangilen, mouth of Ular River, spruce-larch forest, lichens (Hypogymnia) on larch trunk, 5–6.viii.1995, coll. S. Stebaeva.

Russia: Far East: Amurskaya Region: ca. 3 km W Arkhara, southern slope at top of hill, dry young oak forest, litter, 17.viii.2014, coll. M.P. and N.K.; Zeysky Reserve, 52 km of road Zeya-Beregovoy, ca. 800 m alt., mixed forest on northern slope, mosses and lichens on stones, 21.viii.2014, coll. M.P. and N.K.

Mongolia. Arhangay Aymag, 5.vii.1971. coll. E.Martynova (probable type locality)

China. Inner Mongolia Province, Da Hinngan Ling Mts, nearby BaLin, Balin Lama Mountain Forest Park, 48.33302°N, 122.31580°E, 538 m alt., southern slope, young mixed deciduous forest (oak, poplar, birch), thick moss under rock in shadow hollow, moss and lichens on stones. 12.viii.2014, coll. M.P., C.-W. Huang, Y. Luan.

Discussion. This species belongs to the ' westerlundi ' group. V. l a r i c i s was briefly redescribed based on type specimens (Potapov 2001), concluding that it differed from V. westerlundi by darker and uniform pigmentation (Fig. 28) and fewer chaetae on ventral side of Th.III (Martynova 1979, Potapov 2001). According to our new observations, the dens of V. l a r i c i s always has more than 24 anterior chaetae, also in type specimens (20–23 ones were incorrectly indicated in first description), the dens normally has 9 chaetae on the posterior side (3 basal and 3+3 di-de), furca as long as or longer than antennae (1.0–1.1), macrochaetae ca. 4 times longer than inner edge of the claw. In contrast, V. westerlundi has 19–23 (rarely 25) anterior and 2+2 (more rarely 3+2) di-de posterior chaetae on dens, furca shorter than antennae (0.7–0.9), macrochaetae ca. 3 times longer than inner edge of the claw. Habitus of V. laricis and V. westerlundi are given in Figs 23 and 24.

The last two abdominal segments are fused in V. laricis (vs. separated in V. westerlundi). With this character V. laricis is a unique member of the genus and is similar to Pseudisotoma Handschin. Other principal characters of the species (11 chaetae in apical tibiotarsal whorl, quadridentate mucro) indicate the genus Vertagopus.

Distribution and ecology. Inner areas of the eastern Asia including Mongolia and several surrounding territories of Eastern Siberia and China (Fig. 29). It is a rather common species in the south and centre of Buryatia. V. laricis prefers xeric sites and inhabits coniferous litter of dry forests and sparse vegetation on exposed objects.