Tanytarsus oscillans Johannsen, 1932

Giłka, Wojciech & Gadawski, Piotr, 2022, Tanytarsini (Diptera: Chironomidae) collected during Polish expeditions to North Korea, Zootaxa 5214 (2), pp. 151-175 : 161

Tanytarsus oscillans Johannsen, 1932

Tanytarsus oscillans Johannsen, 1932 : Ekrem 2002: 24 (male, figs 34, 35; Indonesia; = Tanytarsus cultellus Chaudhuri et Datta, 1992 , = Tanytarsus sibafegeus Sasa, Sumita et Suzuki, 1999 ).

Material examined. Kaesŏng , 16 July 1981, 4 males ; Sokam , 8 July 1981, 3 males; leg. W. Krzemiński. Comparative material. Tanytarsus smolandicus : Sweden, Nedre Dalälven , 11 August 2003, 1 male , Storsjön , 18 July 2003, 20 males; leg. W. Giłka.

Remarks. Ekrem (2002) redescribed the male of Tanytarsus oscillans based on the holotype specimen. In remarks on its close relatives, T. smolandicus Brundin, 1947 (terra typica in Sweden) and T. unagiseptimus Sasa, 1985 ( Japan) , selected diagnostic characters were indicated to separate these species. It seems, however, that these features (number of median setae, length of frontal tubercles, AR value, presence/absence of microtrichia between anal point crests and slight differences in shape of inferior volsella), in part at least, may be within the morphological variability of T. oscillans and/or T. smolandicus . According to the concept by Lin et. al. (2018b), T. oscillans and T. unagiseptimus are sister species (not ascribed to any group analyzed) while T. smolandicus has not been included. Interestingly, a concept of possible synonymy between the abovementioned names has been raised recently, when DNA sequences from specimens sampled in Fennoscandia and Japan, determined as T. oscillans or T. unagiseptimus , have been compared that resulted in ~97–98% of DNA sequence compatibility (Paasivirta, pers. comm.). Unfortunately, our specimens collected decades ago (kept in denatured ethanol or slide-mounted in Canada balsam) do not give a chance to be analyzed molecularly for supporting this concept.