A new species, Fuscozetes kamchatkicus sp. nov., including its morphological ontogeny, from Kamchatka Peninsula (Russia) is described and illustrated. The adult of this species is smaller and slimmer than congeners and has longer prodorsal seta le than in; in other species in is longer than le. In F. kamchatkicus the shape of the translamella varies (usually is present, but may be narrow as a line or absent), while in other species the translamella is present. The juveniles of F. kamchatkicus differ from congeners by several morphological characters that are unique in Fuscozetes Sellnick, 1928, e.g. they lack a humeral organ, which is present in other species. The larva lacks a humeral macrosclerite, whereas other species have it. In F. kamchatkicus the gastronotal setae are inserted on unsclerotized integument, whereas in other species they are inserted either on the gastronotal shield or microslerites. The nymphs of F. kamchatkicus have a humeral macrosclerite and a gastronotal shield, which is typical of Fuscozetes and Sphaerozetinae (Ceratozetidae), but the humeral macrosclerite bears seta c₁, while setae c₂ and c₃ are inserted on unsclerotized integument, whereas in other species the humeral macrosclerite is glabrous and setae c₂ and c₃ are inserted on microsclerites. In F. kamchatkicus setae p₂ and p₃ are inserted on unsclerotized integument, whereas in other species they are inserted on a macrosclerite. In the juveniles of F. kamchatkicus most gastronotal setae are barbed, except of the d-series in the nymphs, which are thinner than other gastronotal setae and smooth. The diagnosis of Fuscozetes is modified and enlarged with the morphological characters of juveniles.