To combat insect pests, a person uses chemicals. Explain how the life of an oak tree can change if all herbivorous

To combat insect pests, a person uses chemicals. Explain how the life of an oak tree can change if all herbivorous insects are destroyed by the chemical method in it.

1) Most herbivorous insects are pollinators, their destruction will lead to a sharp reduction in the number of insect pollinated plants.
2) This can lead to a reduction in the number or disappearance of second-order consumers (insectivores).
3) Chemicals that got into the soil can lead to disruption of plant life, the death of soil microflora and fauna. All this can lead to serious violations of the ecological balance and even to the death of oak groves.