Opistoclanis is a genus of moths in the family Sphingidae, containing only one species Opistoclanis hawkeri, which is known from China (Yunnan), north-eastern Thailand, Laos and northern Vietnam, where it has been recorded at altitudes between 888 and 2,800 meters.
Adults are on wing from late March to early May at the end of the dry season in Thailand.
References
Opistoclanis Wikipedia(Text) CC BY-SA