I'm now questioning the common identity of Pennisetia marginata. This is the Wikipedia photo.
I'm curious if there are multiple subspecies or if there is some sort of dimorphism going on, because while every science and government chart has them with the black end, the one in the image posted has a yellow end (as do some images posted to the identification). Also some differing features. Could be some sort of hybrid, or maybe even a pure mix up of two different bugs. It's interesting. I've noticed Sesia seem to have the yellow end more commonly.
Here's Sesia tibialis.
Sesia apiformis.
It's definitely showing the behavior, though. I mean, the image is of the thing on a raspberry bush.