Collecting in no-mow zone

Did you have permission to be on the land in question? If no - then you were probably trespassing, and liable to get in trouble.

Keep in mind that 99.9 percent of tallgrass prairie has been plowed under. Those "weeds" themselves are fairly rare and can support populations of insects that are even rarer. People get a little protective about some of the remain tracts of pre-settlement habitats, especially if you didn't bother to ask if you could be on the site.

Shuey

Sounds to me like roadside right of way land which is public property. If it is public land, you can collect unless it is posted with signage.

Depending on local or state laws, the folks restoring the native plants aren't always required to post no trespassing signs. Just because you don't see a sign, it doesn't mean that you can collect where ever you like. And, if it's like some of the areas in my state, where they're spending quite a lot of time and money, trying to re-establish native prairie plants, ...I can assure you, they'd be just as willing to arrest you for tresspass and vandalism as you would be to collect there. Even if the police or wildlife officers don't arrest you, they can be very annoying and could effectively ruin an otherwise good day of collecting.

In the end, conflict like this doesn't serve either side. It makes everybody look silly and churlish. Remember, people are already quick to label collectors in a negative way, please don't give them more material to work with. Ask the person where the boundaries are of the planted area. Show him a little respect, and that you're willing to work with him. Just like we hate to hear people say "It's just an insect...", botanists cringe when people say "It's just a plant..." which is exactly the kind of vibe I'm getting from you.

In the scheme of things, you have a wide variety of places to collect, those plants are extremely limited in where they can grow. The rural world is full of mowers and ruminants.

Who owns the "public property"? County, city, state? Is it a WMA, state park, county park, easement, other? Many of these have specific rules about disturbing/ moving, collecting anything and can vary greatly depending on what type of "public property" it is. Often these rules are not posted, but in the eyes of law enforcement, ignorance is never an excuse. I would think this would be even more likely in a reestablished native prairie.

You've answered your own question. They are operated by UIUC on public lands. You couldn't be arrested for trespassing, but you can be arrested for vandalism.

Something similar happened while I was a student of the college when a drunk kid wandered into the Morrow plots (America's oldest research field). After trampling down corn and ruining an experiment the student was arrested, charged, and expelled.

If you're going to continue to be this arrogant and disrespectful of peoples hard work in restoring small patches of prairie, you should be arrested for vandalism. So go give that guy a piece of your mind - and thanks for giving all of us collectors a bad name.

Quintin,
As Jshuey pointed out, over 99% of the original prairie is gone. There has been a lot of effort to re-establish them at both a large level and personal level (in peoples yards). I'd be willing to bet there there are a lot more people out there interested in planting "weeds" than there are insect collectors. Check out wildones.org