Holotype Male (Fig. 1). China, NW Yunnan, Lijiang/Zhongdian near Tuguancum, 27°29'700"N, 99°53'700"E, 24–25.V.2012, 3200 m, leg. A. Floriani; slide No.: OP1780m (coll. GBG/ZSM).

The name “solaris” refers to the orange circular patch at the reniform stigma resembling the rising sun.

The new species belongs to the olivacea species-group and externally resembles Stenoloba albistriata (Fig. 2) and Stenoloba olivacea (Fig. 3), but is clearly separable from them by both wing pattern and genitalia. The most prominent distinguishing feature, unique within the genus, is the presence of circular orange patches in the forewing basal area and in the reniform stigma. Stenoloba solaris differs from all related species by its forewing’s bright lettuce-green colour, as opposed to the olive ground colour and dark grey hindwings of the other species. The specific features of the male genitalia can be found in the shape of the uncus, juxta, and valvae, and in the structure of the vesica. The male genitalia of Stenoloba solaris (Figs 6, 7) differ from those of Stenoloba albistriata (Figs 8, 9) by the wider base of the uncus, the wider, shorter and less curved valvae, and by the rounded juxta with straight lateral margins. The uncus of Stenoloba albistriata is constricted at the base and dilated medially, the longer and narrower valvae have more curved costal margins, and the juxta has concave lateral margins. The other somewhat similar species, Stenoloba olivacea (Figs 10, 11) and Stenoloba benedeki (Figs 12, 13) each have a longer uncus, rounded juxta, and a large, medially positioned cornuti field consisting of fine spiculi and the terminal cornutus is either small and nail-like (Stenoloba olivacea) or large and thorn-like (Stenoloba benedeki). In addition, the clasping apparatus of the latter two species is significantly larger than in the new species, but the size of the aedeagus and vesica is practically the same.

Male (Fig. 1). Wingspan 34 mm. Head and thorax lettuce green; collar with a row of black scales at base forming black line; tegulae edged by black line; abdomen blackish grey; forewing relatively elongated, with costa remarkably arched, apex finely pointed, outer margin oblique, ground colour lettuce green with dark-grey area medially; wing pattern well marked with well-developed cross-lines; basal field with circular orange patch bordered with white fascia distally; cross-lines black, basal line strongly marked; subbasal line strong, curved, bordered by white fascia proximally; antemedial line waved, oblique with wide white fascia; lower part of medial area dark grey; medial line nearly straight, slightly bent in middle; postmedial line undulate with white fascia; subterminal and terminal lines formed by large black arrowheads. Noctuid maculation typical and well developed; large orange reniform patch, rounded, defined by black scales; inner edge of stigma forming prominent semilunar arch; orbicular stigma black, dot-like; claviform stigma present as diffuse dark streak; cilia dark grey checkered with white. Hindwing grey, discal spot dark grey, terminal line heavy black. Female unknown. Male genitalia (Figs 6, 7). Uncus short and strong, wide at base and tapering towards apex; tegumen somewhat shorter than vinculum; transtilla relatively wide; juxta wide, rounded quadrangular with triangular cleft on posterior margin; vinculum strong, V-shaped; valva simple, elongate, evenly tapering distally and apex rounded, with a few short spine-like setae at apical margin; sacculus elongate, broad; costa slightly concave; clasper forming long, narrow, dorsally dentate plate. Aedeagus short and straight; vesica bulb-like, everted posteriorly, recurved ventrally; medial part of vesica with three diverticula, one with large, stout cornutus.

The single male was collected at ultraviolet light on 24–25 May 2012 near Zhongdian in northwest China’s Yunnan province in the remote Baima Xue mountain range (Fig. 5). The new species was collected at an elevation of 3200 meters in a wide river valley near mountain mixed forests dominated by various conifer trees, bushes and rhododendron. Many other spring Noctuidae species were collected there at that time including Panolis pinicortex Draudt, 1950, Orthosia reserva Ronkay, Ronkay, Gyulai & Hacker, 2010 and Hada antonraui Gyulai, Ronkay & Saldaitis, 2011.