Family Sphingidae Hodges # 7855
Capterpillar foods: dogbane (Apocynum), honeysuckle (Lonicera), bush honeysuckle (Diervilla), and snowberry (Symphoricarpos) (Bugguide)
Differs from other Hemaris species by having black legs, a mostly black underside, and a smooth bottom edge of the clear area on the forewings.
I found 3 Hemaris diffinis caterpillars in 2 days in August of 2014. Two on non-native Honeysuckle, and one on Tinker’s Weed (Triosteum perfoliatum).
8/26/14 on Lonicera tartarica
8/27/14 on Triosteum perfoliatum
9/25/2014 Dark form caterpillar on non-native Honeysuckle