The name Melittia sangaica is probably correct since this species is wide-ranging.
The subspecies (ssp.) or geographical race is incorrect, as ssp nipponica occurs in Japan, nothern China, Korea etc. ie the Paleartic region.
Subspecies sangaica occur from Taiwan to SE Asia & India so this is likely Melittia sangaica sangaica.
You could leave it as Melittia sangaica sangaica, no harm there.
Or, if you prefer as Melittia cf sangaica , meaning it is close to this species & could be it. ( cf= conferus, L. to compare.)
Melittia sangaica sangaica Taiwan,
http://www.boldsystems.org/pics/_w30...1312304936.JPG
TL Seow
PS. Pix 5 looks like a different species. Legs not hairy & forewing unmarked.