Well, I'm not sure that we *should* treat chimps as we *actually do* treat chimps!

But in whatever way we should treat chimps, we should presumably treat members of Homo erectus (were there any alive today) in much the same way. Chimps and members of Homo erectus presumably possess to just about the same degree exactly the same features relevant to moral respect, whether it be the capacity to feel pain, the capacity to think and to know and to plan, self-consciousness, and so forth.

The mere fact that Homo erectus belongs to our own genus (Homo) and stands in a closer evolutionary relationship to ourselves would seem to have little bearing on the moral status of members of that species. To say otherwise would be speciesism -- er, genusism.