How to better understand corn root worm issues and what products are used for in soil?

So I tried conventional corn this past year. It was a big deal for me because being a younger farmer, Ive been taught that I need this trait and that trait otherwise it will all fail. Well after reviewing yield maps, the 80 planted to conventional was the highest yielding farm for me this year with the least amount of inputs and it was standing like a tree. (Results worth pursuing right??) Ive shared my results with a couple of my local seed guys (who are younger and don't want to see me fail, but also are not the ones writing these big checks every year). But all they can say is corn root worm is real and its gonna be terrible next year. They think Smart stax hydrids with insecticides. This is just insane right? I just proved that all that stuff is not needed really. I never want to set myself up for failure, so I'm just curious if anyone has a good soil test that can determine actual larvae threshold for the next growing season. Also how many weeks of residual typically can you get out of granular insecticide and also liquid insecticide? I want to make the decision to grow more conventional corn, but I also want to feel good about making that decision too. Also I want to learn something now while prices are higher so I can be more prepared when our prices head south again. As far as chem program, roundup doesn't do a darn thing for us anymore other than kill some small grass. So I'm not concerned at all with that. Its just better understanding insect pressure and how to effectively identify that there will be yielding robbing issues and control them as needed. Thank you!