OE is so scary for everyone but sometimes when people don't understand enough about OE, they treat caterpillars/butterflies for OE and if it isn't OE, they aren't addressing the real issue and the real cause of the trouble can spread. I'd love to see a good discussion on OE. First, it isn't a disease. Yes, I have often called it a disease and I'm sure I still will but it helps to know that it really isn't a disease. It is a parasite. Second, ONLY an adult butterfly can spread OE. Caterpillars cannot spread OE. If you have 12 caterpillars all together in one rearing container and 6 have OE, when they become adults, 6 will have OE and 6 will not. Third, plants cannot 'have' OE. Plants can only be contaminated with OE like an apple can have common cold germs - the germ has to be placed ON the apple. It can be washed off. Although I don't have all the answers (of course! and all of us wish we did have all the answers), I'd be more than glad to answer any questions about OE that I can answer. Other info: You can tell in pupal stage if it is badly infected, almost every time. A horribly infected adult Monarch can live 6 weeks or more, spreading spores all over the place. Some diseases can be transferred INSIDE the egg and nothing can be done with them. Treating these (pathogen inside the egg) as if they have OE won't help them a bit. They're born with the disease. Learning more about OE parasites and about diseases will help us all raise healthier butterflies.