| abstract | The new species D. ushakovae belongs to the subgenus Serdjukovia Dias, 1963. In its limits the species is most close to D. marginatus Sulzer and D. niveus Neumann. It differs from the first species in a longer shape of maleʼs idiosome, regular light pigment and characteristic punctation of scutum and conscutum; longer setae of femaleʼs alloscutum, more parallelsided peritrema, longer apical cone of tarsus I, longer coxa IV of the male. The new species differs from D. niveus in shorter cornua and backward orientation of their apexes, general proportions of the gnathosoma base, the absence of dorsal denticle on the 2nd joint of palps, smaller number and shorter length of setae on the female alloscutum in the areas between the median and cervical grooves.
The new species is widely distributed in mountain areas of East Kazakhstan, Kirghizia, Turkmenia, 500 to 1800 m above the sea level. It is characterized by a peculiar biotopical adaptation to non-flooded upper terraces of big and small mountain rivers and banks of mountain lakes with a tugai-type vegetation, brush and meadow steppes. D. ushakovae has parapatric relations with the close species D. marginatus and D. niveus.
Golotype: Male. Kazakhstan, valley of the Ghilik river, from vegetation, 29 IV 1977, collector B. D. Lebedev. Preserved in the Zoological Institute, Academy of Sciences, USSR, Leningrad, NJ — 4535. |