Hyloicus formosana
Similar in pattern and male genitalia to Sphinx crassistriga and Sphinx oberthueri.Wings much narrower than in Sphinx crassistriga, forewing with apex falcate, hindwing with apex pointed. Thorax upperside brownish-grey; tegulae with very dark-brown border.Abdomen upperside grey-brown, with black lateral marks and a narrow mesial line. Legs with many small spines; epiphysis slim, pointed, relatively long (3/4 length of the tibia); middle legs with one pair of tibial spurs; hind legs with two pairs; paronychium with only a very short lateral small lobe; empodium thin, with an oblong long seta; hindtarsal claws somewhat longer than those of the two other pairs of legs. Forewing upperside brownish-grey with a general dusting of pale grey scales, and with very dark red-brown horizontal markings; a row of submarginal dark points; a notable whitish oblong mark posterior to vein M3. Underside of both wings unicolourous medium sepia; both wings with a darker postmedian line, which on the forward wings makes a rounded curve costad anterior to vein M3. Hindwing upperside unicolourous sepia. 30-34 mm. Similar to those of Sphinx crassistriga, but:valve more robust;harpe with outer margin dentate at dorsal half, ventral edge more produced;saccus longer;sacculus characteristically with a strongly toothed outer edge;aedeagus sigmoidal, ending in a curved point and with a subapical lateral convexity.