Organic might make a difference with meal moths—I haven’t heard that, but I think it’s mostly from storing things in bags instead of tight metal, glass or plastic containers, having traces of spilled food on shelves and just saving things too long. Also one contaminated thing that somebody gives you can spell trouble. I’m lucky that my best friend is an entomologist though.
I buy flour on sale in quantity, repackage it in freezer ziplocs and put it through my deep freeze for a couple of weeks. Never had a bug problem since I’ve been doing that. Do that to my rice, pasta and cornmeal as well. Organic or otherwise.