Opilio rossicus, Snegovaya, 2016

Snegovaya, Nataly Yu., 2016, Two New Opilio Herbst, 1798 Species (Arachnida: Opiliones: Phalangiidae) From Caucasus Region, Ecologica Montenegrina 8, pp. 27-33 : 28-30

Opilio rossicus , sp. n.

( Figs. 2-19)

Material: Holotype ♂, Paratypes 7♂, 1♀, Russia, Rostov region, Orlov district, vicinity of Manich settlement, Manich-Gudilo Lake Valley , 2- 9.10.2009, leg. Perepechaenko V .L.

Small size harvestman, 2.9 long, 1.6 wide. Body surface covered with trasverse rows of denticles along margins of tergites. Color of the body light-brown with dark-brown dorsal part. Group of denticles are situated in front of eye mound. Eye mound low, typical for Opilio genus, with 3-4 denticles on each side. Legs short, femora I short (1.75), cylindrical, much thicker than other legs, densely covered with transverse rows of denticles ( Table 1).

Pedipalps small, femur dorsally with black-tipped denticles, ventrally and laterally with large denticles, patella dorsally and ventrally with denticles, tibia dorsally and ventrally with several denticles. Pedipalp lengths 1.4+0.25+0.5+0.95 = 3.1. Chelicera small, basal segment dorsally with some denticles. Cheliceral basal segment length 1.1, distal segment 1.1. Penis small with wide base (1.65 long, glans 0.2, stylus 0.08) narrows to glans, wings small size, glans of the penis oval in form with 2 pairs of setae.

Female differs from male by being larger in size, more oval form of the body and less developed denticles on the body and extremities. Female body length 4.8, wide 2.5. Pedipalp lengths 0.9+0.4+0.6+2.4 = 4.3. Cheliceral basal segment length 2.1, distal segment 1.25.

Diagnosis – The new species is closely related to Opilio caucasicus Snegovaya, 2010 and Opilio lederi Roewer, 1911 , but differs from O.caucasicus by the smaller body size, differences in penis structure: Opilio caucasicus has a large glans, significantly wider base and wider wings. From another species O.lederi , the new species differs by the smaller size, form of femur I and details of the penis ( Table 2).

Etymology. The species is named after Russia, the country from where it was discovered.