To your point, I think a lot of folks forget how much "terraforming" we're doing all of the time. Entire expanses of grasslands and forests are growing and being re-leveled.

A look at Google maps satellite demonstrates changes of color (dark green to light green and vice versa) across parts of several continents, changes that ebb and flow in big ways over just decades. I think this would very much affect insect (and animal and plant) populations.