(Figs 53–57, 158)
Ectoedemia jacutica Puplesis 1988: 26.
Ectoedemia jacutica Puplesis, in Stonis et al. 2015: 116–122; Yagi et al. 2019: 226, 227.
Material examined. 2 ♂ (holotype and paratype): Russia, Eastern Siberia, Sakha Republic (former Yacutiya), Yakustk, 05.vii.1986, A. Rastorguev, genitalia slide nos AN540 (holotype, in poor condition), AN539 (paratype) (ZIN); 1 ♂ [examination based on the genitalia photographs only], Russia, western Altay, Katun valley, Mikkola et al., genitalia slide no. 15041 JCK (courtesy of E. J. van Nieukerken, Naturalis Biodiversity Centre, Leiden, the Netherlands).
Diagnosis. This species belongs to the Ectoedemia angulifasciella species group. Ectoedemia jacutica is the most similar and probably closely related to the European E. spiraeae Gregor and Povolný and Himalayan E. orbiculata sp. nov. (see described above).
From the related E. spiraeae and E. orbiculata, the males of E. jacutica differ in the tufts of the wings: Ectoedemia jacutica is characterized by the presence of a brown, weakly-developed tuft on forewing underside (Fig. 54) (white in E. spiraeae, absent in E. orbiculata), inconspicuous costal bristles and hair pencil on upper side of male hindwing (E. spiraeae possesses a yellowish white tuft, E. orbiculata has a brown tuft). The specimens of the type series also were characterized as having glossy, greyish white fascia (in E. spiraeae fascia is non-glossy, cream, in E. orbiculata, fascia is replaced with cream, non-glossy, dorsal spot).
In the male genitalia, the combination of a proximal excavation of the vinculum (Fig. 158), bulged inner margin of the valva (Fig. 158), with a relatively small apical process (Fig. 158), short sublateral processes of the transtilla, and a caudally slender pseuduncus distinguishes E. jacutica from E. spiraeae and E. orbiculata.
Possibly, the boreal distribution of E. jacutica also may distinguish the latter from the Himalayan E. orbiculata, which occurs in a humid, subtropical habitat.
Remarks. Forewing length 2.5 mm; wingspan 5.5 mm (n = 2) (Fig. 53). Male genitalia with a distinctive proximal excavation of vinculum (Fig. 158), relatively small apical process and bulged inner margin of valva. For a description see Puplesis 1988 (in Russian) or Stonis et al. 2015 (in English).
Bionomics. Host plant is unknown because it is still unclear if specimens from Japan and China, associated with Aruncus dioicus (Walter), Spiraea salicifolia L., S. chamedryfolia L., and S. japonica L., Rosaceae (Yagi et al. 2019), are E. jacutica or a different species.
Distribution. Originally this species was known from a single locality in eastern Siberia, Yakutsk (Fig. 1: Ya). Additionally, the specimen collected in the western Altay (see Material examined, Fig. 1: Al) also belongs to E. jacutica (see illustrated in Stonis et al. 2015: fig. 12). The recent discovery of E. jacutica in Japan and China (Yagi et al. 2019) may be correct, however, it needs confirmation.