Sphinx caligineus brunnescens Mell, 1922, Dt. ent. Z. 1922: 113. Type locality: China, north Yunnan, montane forest.
Note. Mell (1922a) described brown specimens of what he took to be Sphinx caligineus from northern Yunnan as Sphinx caligineus brunnescens, a subspecies that he claimed was confined to montane forests. Later, however, he also referred specimens from northern Guangdong and southern Hunan to this subspecies (Mell, 1922b) and stated that Sphinx caligineus brunnescens was intermediate ('ein Mittelglied') between the dark brown Sphinx caligineus caligineus (Butler) from Japan and the paler grey Sphinx caligineus sinicus (Rothschild & Jordan) from 'Zocé' (= Sheshan), Zhejiang. On 30.vi.1995, the first author captured a specimen of Sphinx caligineus at Hangzhou (Zhejiang) that was transitional in colour between Sphinx caligineus sinicus and Sphinx caligineus brunnescens. In addition, there is a brown female in the IZAS from nearby Sheshan (Zhejiang) (the type locality of Sphinx caligineus sinicus) that matches the description of Sphinx caligineus brunnescens, while grey specimens of what appear to be Sphinx caligineus have been captured at 2250m in northern Yunnan (Pittaway & Kitching, 2000). We therefore initially considered it likely that Sphinx caligineus brunnescens was simply a colour form of Sphinx caligineus sinicus, analogous to the brown forms that exist in the European species, Sphinx pinastri Linnaeus (Pittaway & Kitching, 2000).
However, with the description of Sphinx yunnana Brechlin, 2015 (from Yunnan), and Sphinx centrovietnama Brechlin, 2015 (from Vietnam), the situation with regard to the nomenclature and distribution of this subspecies, Sphinx yunnana, Sphinx centrovietnama and Sphinx caligineus sinicus has become even more confusing. The grey specimens of Sphinx caligineus mentioned above, which were captured at 2250m in northern Yunnan, have been confirmed as being Sphinx yunnana. In fact, all individuals of Sphinx caligineus sinicus from Yunnan and Sichuan mentioned in Pittaway & Kitching (2000) are Sphinx yunnana. As no individuals of Sphinx caligineus have ever been confirmed from Yunnan and Sichuan, the brown individuals that Mell (1922a) described from northern Yunnan could well be the brown form of Sphinx yunnana. Using DNA barcodes, the Sphinx caligineus brunnescens-like individuals recorded from NE Laos have been confirmed as being Sphinx centrovietnama (Ian Kitching, pers. comm. 2018), a species which appears to extend northwards into southern China.
No type material of Sphinx caligineus brunnescens could be found in CMNH or MNHU; specimens labelled 'type' in CMNH or 'paratype' in MNHU do not have appropriate data. Danner, Eitschberger & Surholt, 1998, Herbipoliana 4(1): 58, erronously gave the type-locality as 'Bergwälder im Norden der provinz Kuangtung'. The above confusion cannot be fully resolved until the types of Sphinx caligineus brunnescens have been examined. Depending on what it turns out to be, this name will probably replace either Sphinx yunnana or Sphinx centrovietnama.
There is also a further complication. In the final instar the larva of this taxon is more similar, but different, to that of Sphinx caligineus caligineus (Butler, 1877) from Japan, rather than the more northern Chinese Sphinx caligineus sinicus (Rothschild & Jordan, 1903). In fact, there are enough differences in coloration and patterning between the larvae of all three taxa to indicate that they may be distinct species and not just subspecies.
China: 2.vi (Zhejiang); 15.vii (Hunan); ?vii-ix (Yunnan).
China: Zhejiang (Sheshan); ?Sichuan (Yibin); ?Yunnan (north; Songzishanding, Changning County, 2500m); Hunan (Nan Ling Shan, 750m); Guangdong.
Endemic to southeastern China, and maybe across/down to northern Laos (near Phonsavan, Xiangkoang Province (Alexandre Teynié/Jean Haxaire, pers. comm. 2018)) and northern Thailand (Inoue et al, ) as Sphinx centrovietnama. Specimens of Sphinx caligineus brunnescens recorded from Sichuan and Yunnan may be the brown form of Sphinx yunnana Brechlin, 2015, but this requires clarification.