The problem with this question is generalized for all consciousness research: the term "consciousness" is ambiguous and means different things to different people. For some consciousness just means "higher-order awareness". For others it means "subjective experience". Insects surely don't have higher-order reflective consciousness. But perhaps they have subjective experience.
But how would we ever determine that empirically? Can we build a measuring device that when we point it at insects it goes "BING!" and detects consciousness? But how would we know if the measuring device was measuring things properly? We'd have to calibrate it. But to do so we'd have to have a "standard" by which to calibrate. But we have no such standard because there is no agreed upon theory of consciousness that can be used to determine the appropriate way to build a measuring device.
The entire field of consciousness studies is built upon sand. It's not an empirical field. And to the extent it is empirical it is built upon stipulative definitons: someone might stipulate what they mean by consciousness is higher-order cognition, then operationalzie that concept and study it, but why should we agree with that stipulation? The field is hopeless.
Great post though.
Thank you and thank you for the intelligent reply. It's more an philosophical question than a empirical one. But an interesting question none the less.
Empiricism isnt the only way to reason.