Smerinthulus taiwana Haxaire & Melichar, 2022, European Entomologist 14(1+2): 12. Type locality: Taiwan, Nan-Ta [Nantou Hsien], Pu-Li [Puli], Sang-Gan [Songgang], vi.2007 (ex coll. H. Schnitzler).
Note. A relict species related to Smerinthulus witti Brechlin, 2000, from Yunnan (mainland China), and Smerinthulus arunachalensis Melichar & Haxaire, 2022 from Arunachal Pradesh (India) (Haxaire, Melichar, Kitching & Brechlin, 2022).
According to Haxaire, Melichar, Kitching & Brechlin (2022), the basic hue of the forewing upperside is yellowish beige. The forewing is crossed by a dozen blurred and indistinct undulating lines, but this may be due to the worn condition of the holotype specimen. The black discal spot is particularly prominent. There is a small black mark on the inner margin, just before the tornus. The hindwing is reddish-brown, with the only feature being a slight darker postmedial band.
The underside of the forewing is paler yellow than the upperside, making the black discal spot even more visible. A thin submarginal line crosses the wing from the dorsum to the costa. A small black spot is present on the costa just before the apex, and a larger second spot is present in the concavity of the dorsum just before the tornus (as on the upperside).
The ground colour of the underside of the hindwing is the same pale yellow hue as the forewing, finely punctuated with minute brown dots. This wing is crossed by two brown-black lines, the antemedial being extremely diffuse, the postmedial being thin and distinct. In the submarginal area, more or less distinct black markings are present in the area between veins M2 and CuA2.
The male genitalia are of the 'witti' type, with an elongate uncus, with a shallow apically concavity flanked by two small, sclerotized points. The gnathos is present, triangular with a rounded apex. The shape of the valve is very close to that of Smerinthulus witti. The rounded ventral lobe is practically identical, but longer, and curved downwards, giving it the shape of a bean. The terminal claw is much broader than in Smerinthulus arunachalensis and longer than in Smerinthulus witti.
Taiwan: vi (Nantou Hsien).
Larval hostplants. Unknown.
Taiwan: Nantou Hsien (Puli; Ren'ai Township, 2300m; Tsueifeng, 2200m.)
Endemic to the highlands of Taiwan and, so far, it has only been found at the highest elevations of Nantou County.
Holarctic; eastern Palaearctic region. Pleistocene refuge: Monocentric -- Taiwan refugium.