[en] Nonlinear gyrokinetic simulations of microturbulence simultaneously driven by electron temperature gradient modes, trapped electron modes, and ion temperature gradient modes are presented, covering both electron and ion spatiotemporal scales self-consistently. It is found that, for realistic ion heat (and particle) flux levels and in the presence of unstable electron temperature gradient modes, there tends to be a scale separation between electron and ion thermal transport. In contrast to the latter, the former may exhibit substantial or even dominant high-wave-number contributions