This winter when the bulletins about the MSB came out I realized they have been on my farm the past 2 seasons and ruining a lot of the red raspberries. And I assumed this year would be far far worse because there are no known predators of the pests (and also because I now had a name for the scourge and the various state extension services that have issued bulletins had scared the bejeebus outta me over this). So this week the raspberries started to ripen (about 14 days late) and I was prepared for the worse. And on day one of harvest there was quite a bit of damage but it was mainly bird and Japanese beetle damage with only about 10% to 15% being due to MSB-not too bad. By the end of the first full week of harvest the MSB damage had fallen to maybe .1%-about 1 in 1000 berries is effected (and they stink so badly it is very easy to find them and toss them out)
I also noticed a huge number of wheelbug youngsters in their 3rd and 4th instars (and possibly an adult). There were something like 4 per square foot. In past years, since I researched this insect, I would see maybe on every 10 square feet or fewer. I figured they were pretty territorial and that was why we had a lower population as well as being a top predator. But I also knew we had some rather underfed larva the past couple of years which would of course mean fewer making it to adult stage so fewer numbers that could breed to increase the population. So far this year i have seen nothing but fat and happy wheelbug larva
I do know that I definitely saw wheelbugs eating MSBs last year (I wondered what kind of stinkbug it was as it had more white spots on it that the other 3 or 4 species we have around here, now I know) and it would make sense as the MSB population increases that the wheelbug population would increase a couple of years behind them.
So I believe we have a native insect in the Eastern US that can control the MSB scourge.