Ephysteris tenuisaccus Nupponen

Junnilainen, Jari & Nupponen, Kari, 2010, The gelechiid fauna of the southern Ural Mountains, part I: descriptions of seventeen new species (Lepidoptera: Gelechiidae), Zootaxa 2366, pp. 1-34 : 24-26

Ephysteris tenuisaccus Nupponen sp. n.

Figs. 50–54

Type material. Holotype: 3 (Fig. 50): Russia, S Ural, 50°40–45’N 54°26–28’E, 220 m, Orenburg district, Pokrovka village 20 km S, Schibendy valley, chalk steppe, 07.VI.1998, leg. T. & K. Nupponen ( TKN, to be deposited in ZMH). Paratypes (55 3, 21 ƤƤ): Same data as holotype except for dates: 07.VI.1998 (44 3, 14 ƤƤ), 21.VI.1999 (9 3, 4 ƤƤ), 22.VI.1999 (1 3), 23.VI.1999 (2 ƤƤ), 10.VI.2001 (1 Ƥ) ( TKN, ZMUC). Same locality as holotype, 03–07.VI.1998 (1 3), J. Junnilainen leg. ( JJ). Genitalia slides: K. Nupponen prep. no. 1/ 28.II.2001 (3), 2/ 28.II.2001 (Ƥ). Two further genitalia preparations preserved in glycerol.

Diagnosis. E. tenuisaccus sp. n. is placed in Ephysteris on the basis of the arrowhead-shaped signum and parallel lateral sclerotization of the ductus bursae, as well as a long, straight aedeagus with subspherical caecum and a long, thin, apically more or less pointed saccus. The morphology of the male and especially female genitalia indicate a close relationship to E. deserticolella (Staudinger, 1870) . Externally E. tenuisaccus is easy to separate from closely related species by its uniform creamish white ground colour and distinct dark brown spots of the forewings. The male genitalia differ from those of E. deserticolella by a much thinner saccus, a broader uncus, a strong and distinct gnathos-hook and a short semicircular processes of the vinculum divided by a narrower medial emargination. In the female genitalia the signum of E. tenuisaccus resembles that of E. deserticolella , but the antrum is quadrangular, longer and narrower than in E. deserticolella . The shape of antrum separates E. tenuisaccus from all other known species which have a similar arrowheadshaped signum, e.g. E. promptella (Staudinger, 1859) , Phloeocecis cherregella Chrétien, 1908 and Vladimirea amseli Povolný, 1967 .

Description. Wingspan 10.5–12.5 mm. Head, collar, neck tuft, haustellum, labial palp, thorax and abdomen uniform creamish white, except apex of labial palp with a few darker scales. Antenna pale fuscous with numerous distinct dark brown rings from base to apex. Legs creamish white, fore- and midlegs tibia with 6–7 more or less indistinct dark brown rings. Ground colour of forewing pure creamish white with the following dark brown pattern: distinct spot at 0.1 near costal margin; two distinct roundish spots near fold at 0.3 (dorsally) and 0.4 (costally); more or less distinct dash medially at 0.7, often connected with indistinct costal and dorsal dashes forming incomplete fascia; indistinct subterminal fascia; a few brown-tipped scales over the wing, especially at medial 0.3 near costal and dorsal margins and at cilia; in some specimens further spot on costa at 0.25 and/or on fold at 0.15. Hindwing whitish fuscous, basal area paler, cilia cream-coloured.

Male genitalia (Figs. 51–52). Uncus subtriangular, broad. Gnathos base large; gnathos hook well developed, basally broad, rapidly tapering up to 0.6, apical 0.4 bent, tip pointed. Tegumen rather deeply emarginated anteriorly, pedunculus elongated. Transtilla a pair of weakly sclerotized, parallel, oval structures. Valva moderately long, extending to middle of uncus, rather thin, bent at basal 0.7, apical 0.3 slightly broadened, tip rounded; weak longitudinal fold at apical 0.7. Sacculus extending to middle of valva, digitate, slightly bent, apically setose. Vinculum with rather robust, setose, semicircular medial processes, divided by deep and narrow U-shaped emargination; at ‘bottom’ of emargination a sclerotized fold. Saccus thin, as long as valva; apical 0.2 thinner than basal part, apex more or less pointed. Aedeagus 1.4x length of valva, straight; caecum short, subspherical; subterminal claw broad with convex posterior margin; cornuti absent. Tergum VIII subtriangular, anterior margin concave. Sternum VIII subtrapezoid, posterior margin shallowly emarginated medially. Abdominal segment I as in (Fig. 52).

Female genitalia (Figs. 53–54). Antrum rectangular, 1.3x as long as wide. Ductus bursae proximally with weak parallel lateral sclerotization. Signum arrowhead-shaped with three tapered and pointed lobes; apex elongated. Apophyses posteriores long and slender. Apophyses anteriores 0.45x length of apophyses posteriores.

Bionomy. The type series was collected in June from a chalk steppe. The majority of the adults were swept on Hedysarum sp. and Nanophyton erinaceum (Pallas) in the afternoon sunshine. Occasionally few specimens came to artificial light at night. The host plant of this species remains unknown. Possibly the moths were only hiding under plants, because the vegetation is very sparse on the slope. The larval host plants of the species belonging to the genus Ephysteris are known only in a few cases (see Karsholt & Sattler 1998; Povolný 2002).

Distribution. Russia (S Ural). Only known from the type locality.

Etymology. Lat. tenuis = thin. The species name alludes to a thin saccus in the male genitalia, one of the characters separating the new species from closely related E. deserticolella .

Remarks. Povolný (1996) placed Microcraspedus Janse, 1958 as a subgenus of Ephysteris Meyrick, 1908 , while Povolný (2002) treated them as separate genera. The former treatment is followed here. Thus, E. tenuisaccus belongs to the subgenus Microcraspedus . There are several species living in Schibendy valley that have the pale colour form of the moth, reflecting the pure creamish white ground colour of the biotope; so far they are known only from that locality. If E. tenuisaccus will be found in other localities, it is possible that the moths will be darker coloured than the type specimens.

PLATE 10. Figures 50–54. Ephysteris tenuisaccus Nupponen sp. n. 50. Imago (male, holotype); 51. Male genitalia (paratype; slide KN 1/ 28.II.2001); 52. Abdominal segment I (up) and VIII (down); 53. Female genitalia (paratype; slide KN 2/ 28.II.2001); 54. Signum (paratype; slide KN 2/ 28.II.2001).