I've eaten various borer beetle grubs that I've found while splitting wood for years. The taste varies depending on the wood they come out of in my experience. Cherry, Maple, and Poplar are quite good - sweet even. I've eaten some out of oak that were a little tart, same with pine.
I've also eaten the white grubs (from rhino, big head, scarab, and june bug beetles) found in the ground and under logs (as shown in the video) they don't have much of a taste and can be a little gritty. I've had no issues eating these ground grubs either.
I've had no issues to date with the consuming of these grubs, and have found a lot of literature supporting the practice.