"Can this insect be identified?"
The Answer is: "It depends."
Some species are unmistakable and can always be safely identified. But for the majority, leaving aside data quality (specimen condition, photo quality, estimated sizes), specimens vary. In some cases being able to see a certain key feature always works, no matter the size, shape or colour. For other species, intermediate or atypical specimens cannot be safely identified. The choice then is simply to pretend you never saw them, to record at genus level, or to record as Genus c.f. species. In other words, it is not possible to safely identify every specimen.
Annoying, isn't it?