A new species Neodermation actitis sp. nov. (Acariformes: Dermationidae) is described from the Common Sandpiper Actitis hypoleucos (Linnaeus) (Charadriiformes: Scolopacidae) in the Russian Far East using light and scanning electron microscopy. The new species differs from the closely related Neodermation belonopteri Fain, 1964 in the following features: in males, the hysteronotal shield is distinctly ornamented (vs. unornamented in N. belanopteri), setae e2 are situated on the hysteronotal shield (vs. off this shield), the external projection of the terminal membrane is triangular and subequal to the median one (vs. smaller than the median projection); in females, the postero-lateral projections of the hysteronotal shield are strongly sclerotized (vs. sclerotized as other parts of this shield. An emended diagnosis of the genus Neodermation is given. Differences in the external morphology of male and female tritonymphs of N. actitis are also described. Precopulatory mate-guarding behavior is recorded for the first time for dermationids.