Pneumolaelaps marginepilosa Sellnick

Pneumolaelaps marginepilosa (Sellnick)

Figures 62–66.

Specimens examined. Two females, RUSSIA, Tyumen Province, vicinity of lake Kuchak, 57°21’N, 66°03’E, 27 April and 06 September 2018 O. Joharchi coll., on Bombus sp. (Hymenoptera: Apidae).

Notes. Pneumolaelaps marginepilosa was described from Iceland (Sellnick, 1940) where it was found on Bombus jonellus Kirby (Hymenoptera: Apidae). Bregetova (1977) and Karg (1993) considered that Pneumolaelaps marginalis is a junior synonym of Pneumolaelaps marginepilosa. Pneumolaelaps marginalis was described from Germanny (Willmann, 1953). It has been found on Bombus mucidus Gerstäcker (Hymenoptera: Apidae) (Willmann, 1953). This species widely distributed in Europe and Russia in association with bumblebees or their nests (Bregetova, 1977; Karg, 1993). In addition, Davydova & Nikolsky (1986) reported this species from Western Siberia on the basis of specimens collected on bumblebees. We have not had the opportunity to examine any specimens to confirm this identification. Our specimens agree well with the descriptions given by Sellnick (1940, Figs 86–95) and Evans & Till (1966, Fig. 34). The species is easily recognised by cells of reticulation of dorsal shield small, mostly as long as wide, dorsal shield setae j2, j3, z2–z4, s1–s4 and r2–r5 as long as j1, setae of opisthonotal area decreasing in length from anterior to posterior (Fig. 62), pre-sternal and sternal shields well separated, posterior margin of sternal shield strongly concave (Fig. 63), poststigmatal plate prominent, elongated triangular, genital shield elongate, rounded posteriorly, surface with irregular diagonal lines and polygonal cells (Fig. 63), anal shield nearly as long as wide (Fig. 63), hypostomal groove with six rows, each row with 3–12 denticles (Fig. 66). Opisthogastric cuticle and lateral margins densely hypertrichous, more than ten pairs of long setae in the area between genital and anal shield (Fig. 64).