Hemaris ducalis Staudinger, 1887, Stettin. ent. Ztg. 48: 66. Type locality: [Uzbekistan,] Namangan.
Note: Hemaris ducalis lukhtanovi Danner, Eitschberger & Surholt, 1998 is known only from an isolated population at Ziarat, near Quetta in Baluchistan (Danner, Eitschberger & Surholt, 1998), but its validity as a separate subspecies remains open to doubt (Kitching & Cadiou, 2000).
Wingspan: 40--50mm. Forewing almost fully scaled, the third abdominal segment yellowish white with any brown being confined to lateral tufts, and pulvillus absent. According to Rothschild & Jordan (1903), the male genitalia are rather distinctive; left valva more slender than in Hemaris tityus, approaching that of Hemaris fuciformis; process of left sacculus represented by a conspicuously spinose hump; right valva ventrally slightly emarginate beyond middle; process of right sacculus long, slender, slightly club-shaped, upper surface in apical half armed with long spines. Juxta rather densely covered with long hairs apically; aedeagus rather long, not very sharply pointed. A high-altitude montane form from Tajikistan, f. efenestralis Derzhavets (1984), has the hyaline windows of the forewing partially obscured by dark scales on the side towards the outer wing margin; the windows are completely obscured on the hindwing. In the Ziarat specimen from Pakistan, the forewing hyaline windows are barely visible, being almost totally obscured.
Diurnal. Found in woodland and scrub, rarely below 2300m and occurring up to 6200m.
China: 15.v (Baicheng); vi (Xinjiang, 6200m); 5.vii (Shihezi area); vii-viii (??Sanka).
LARVA: Early instars undescribed. Full-fed 33--42mm. According to Degtyareva & Shchetkin (1982), the fully-grown larva resembles that of Hemaris fuciformis: dorsally and laterally pale green with a prominent yellowish white dorso-lateral line running from the first thoracic segment up to a slightly curved caudal horn; however, unlike Hemaris fuciformis, Hemaris ducalis bears a line of pale yellow V-shaped markings dorsally, one per segment but less pronounced on the thoracic segments, all pointing caudad. Ventrally, reddish brown with a fine, light yellow ventro-lateral line separating the dark lower surface from the green sides. Where this line crosses the prolegs it thickens and becomes darker; true legs brownish cream. Horn 5mm long, violet-black at base and whitish green or cream towards the tapering tip. As in Hemaris fuciformis, the rounded head is bluish grey and offset by a cadmium-yellow collar to the first thoracic segment. A line of the same colour also edges the anal flap. The entire head, body and horn are covered with pale tubercles, light yellow dorsally, mostly becoming cream below the dorso-lateral line. Oval spiracles reddish brown and cream.
PUPA: 37mm. Blackish brown, rugose, very similar to that of Hemaris fuciformis. The overwintering stage.
Larval hostplants. Unknown in China but recorded in Tajikistan on shrubby Lonicera growing in the understorey of spruce forests (Degtyareva & Shchetkin, 1982).
China: Xinjiang (Baicheng, 2400m; ??Sanka, Tian Shan, 2500-3500m; Shihezi area).
Recorded from the mountains of southwestern Xinjiang, China, the western Tian Shan, southern and eastern Kazakhstan up to the Altai Mountains (Yakovlev & Doroshkin, 2005), western Mongolia (Yakovlev & Doroshkin, 2005), southern Uzbekistan, Kyrgyzstan (S. Toropov, pers. comm.), Tajikistan (Grum-Grshimailo, 1890; Eitschberger & Lukhtanov, 1996), northern Afghanistan (Ebert, 1969) and northern Pakistan to Ladakh (Smetacek & Kitching, 2012). Also Ziarat, near Quetta, Pakistan (one specimen in BM(NH) coll.) as an isolated population at 2400m and, maybe, as a separate subspecies (Danner, Eitschberger & Surholt, 1998).
Holarctic; western Palaearctic region. Pleistocene refuge: Monocentric -- Turkestan refuge.