Q2.
Don’t the insects that made the damage fossilize too? How can you tell who made the trace?
A2.
Not usually. Leaf damage is common in the fossil record, but the insects that made it are much harder to preserve.
Explanation

In some cases, the plant-feeding arthropods can also be preserved as body fossils, but they rarely remain together with the same rock as the damaged plants. Many herbivorous insects are small and soft-bodied, so they are less likely to fossilize, and the conditions that preserve leaves are often different from those that preserve delicate animal bodies.