People aren't as densely packed in most parts of Texas, so it might be explainable that way. A lot of the state is also hay fields instead of food crops that are more intensively controlled for pests.

But I've noticed a big change in Texas in recent years. The last two years I haven't had to use pesticide in my residential vegetable garden. I've had to control for mold/fungal infections, but not for insects. And I live up against a nature preserve and try to keep most of my property as natural as possible.