That was about a decade ago, wasn't it?

It was crazy. If you walked outside, you'd have two or three of them crawling on you by the time you walked back in. They'd find their way into your house, your car - you'd breathe them in if you weren't careful.

I still don't understand what happened. They were a brand new / invasive species, but their initial surge was biblical in proportions - a "swarms of locust"-like plague. In the years that followed, the population dropped to the point you would only see them if you looked.

Somehow an equilibrium was reached. I'm not exactly sure why the first year was so severe.

The only similar event I can recall were the swarms of Japanese beetles (false June Bugs) in the 90's. Those were so bad that if you shook any standing tree, a thousand of them would drop on your head. But that only happened every seven years or so.

Perhaps they're all periodic, like cicadas?

https://en.wikipedia.org/wiki/Periodical_cicadas

>Somehow an equilibrium was reached. I'm not exactly sure why the first year was so severe.

Isn't that obvious? It's a species specialized to feed on one plant, and it met a huge amount of that plant which was previously undisturbed by its preying. The result is explosive, actually exponential growth, until there are more beetles than the plant stock can support. Then the beetle population collapses, and after that an equilibrium develops. Cyclical variations can develop under certain circumstances, especially when there are strong seasons.

It is not at all specialized on a single plant. It seems to like almost any leguminous plant. The reason it's considered invasive is because of the large variety of commercially important crops it also feeds on like cowpeas, soy beans, green beans, etc. Kudzu, wisteria, etc are not as commercially important but also are eaten

Ah, I assumed that it was specialized because it's called "kudzu bug" in the article. Still, the same logic applies: the species encountered a new habitat where its particular niche was probably not filled, enabling explosive growth.

I read up more and it's actually many many non-leguminous plants it attacks too. Seems like basically anything. There are native pests like that for pretty much every plant that grows in large populations so I highly doubt it found a new niche. It's success specifically seems to be due to just how much of a generalist it actually is

A more likely, though surely still incomplete, explanation may be due to the fact that the insecticides you need to repel it are broad spectrum and would kill beneficial insects just as well. Most other bugs that fulfill this ecological role have very targeted insecticidal sprays. So they end up at a comparative disadvantage to this generalist

A more likely explanation for their sudden decline imo is that there was probably some virus or other disease that evolved to pray on this now-ubiquitous bug. The bug also has a very particular relationship with its symbiotic gut microbes that seems really important. Such a virus/disease could also have targeted this symbiote. Either way I think the more likely explanation is that this generalist was countered with something that learned to specialize in it

That's certainly also a possibility. Could also be a combination of factors.

> Somehow an equilibrium was reached. I'm not exactly sure why the first year was so severe.

FTA: “The Japanese kudzu bug, first found in a garden near Atlanta’s Hartsfield-Jackson International Airport six years ago, apparently hitched a plane ride and is now infesting vines throughout the South, sucking the plants’ vital juices.”

Looks like they have an enemy in the us that needed time to get to them.