Macrosila obliqua Walker, 1856, List Specimens lepid. Insects Colln Br. Mus. 8: 208. Type locality: Ceylon [Sri Lanka].
Synonym. Macrosila obliqua Walker, 1856.
Synonym. Sphinx nestor Boisduval, 1875.
Synonym. Diludia obliqua Butler, 1877.
Wingspan: 120--145mm. Although confused with Psilogramma menephron by Hampson and some other authors in the past, difficult to confuse with any other sphingid -- the combination of the labial palp structure, long thorax and wing pattern is unique. Proboscis much longer than body. Labial palp distinctive: segment two triangular, much shorter than segment one; apex of segment one with large cavity. Thorax very long, extending far beyond base of forewing. Forecoxa with conspicuous hair pencil. Mid- and hindbasitarsal combs present, conspicuous. Pulvillus with two lobes. Arolium present.
In the male genitalia, tergite A8 with an apical row of elongate, tawny stridulatory scales, these angled inside but not forming a ribbon (as in Ambulycini and some Smerinthini). Uncus resembling that of Agrius convolvuli in dorsal view but more slender in lateral view, gradually tapering to a point. Gnathos with a broadly rounded median lobe, convex below. Harpe with a broad, upwardly recurved dorsal hook; ventro-apical hook of other Acherontiini replaced by a series of multiple hooks along entire distal margin. Valve with large patch of multidentate stridulatory scales. Aedeagus broad, lacking terminal processes. In the female genitalia, antevaginal plate membranous and folded proximally. Anterior margin of ostium bursae formed into a truncate, feebly sinuate lip with prominent angles. Postvaginal plate more strongly sclerotized, smooth, short.
China: 27.vi (Yunnan).
LARVA: Dvořák (2016) illustrates a larva which is claimed to be of this species, even though it was never reared through to the adult stage.
Larval hostplants. Reputed to be Spathodea campanulata and Oroxylum indicum (Bignoniaceae) in the Philippines (Dvořák, 2016)
China: Yunnan (Pingbian County, Dawei Shan Nature Reserve, 2000m; Yinjiang; Gaoligong Shan); Hainan.
Sri Lanka, north-eastern India, Burma/Myanmar, south-western China (Yunnan, Hainan), Thailand, northern Vietnam, Malaysia (Peninsular, Sarawak, Sabah), Indonesia (Sumatra, Kalimantan, Java, Ceram, Papua Barat), Philippines (including Palawan), Papua New Guinea, Solomon Islands.