Any change that is beneficial to the breeding habits of a species will give you more of those bugs in any given year. Temperature, moisture, available food, and lack of predators all play a role just like with larger species.
Our insect menace this year seemed to be June beetles. Those little suckers were everywhere! Usually on summer nights, we’ll see a few hanging out on the windows, attracted by lights. This year, as soon as the sun went down there would be dozens of them crawling on the outside of our windows. They ate all of my basil. :( We also had a lot more Japanese beetles than we usually do. When the kids and I went to pick raspberries, the Japanese beetles were all over the raspberry bushes. They make a loud buzzing noise when they fly, and they kept landing on us. I’d never seen so many beetles on the raspberries before. Our summer was much hotter and drier than usual, so maybe it had something to do with that.