The City Council held a study session on March 10, 2026, covering four major agenda items: spongy moth management, a downtown infrastructure and transformation update, a housing code update, and an update on the Any Path Home homeless initiative. Presentations were given by Minnesota Department of Agriculture staff, city administration and community development staff, and Councilmember Dory. No formal votes were taken, but clear directions were provided on several issues.
Rochester City Council study session, and we are in our more informal setting again, which I think uh really is conducive to a great dialogue, which we have two weeks ago. Uh, today's agenda we have four items. We have spongy moth management in Rochester, uh, and then we have uh supporting transformation update, a housing code update, and then we'll hear from our colleague, uh council member um Dory on any bath home program update. So with that, I am going to turn it over to Kimberly Bramers and John Larson from uh the Department of Agriculture. Well, thank you, uh Council members. Uh thank you so much for having us. My name is Kimberly Tilling Kramers. Um I'm with the Minnesota Department of Agriculture. I'm a manager at the department, and with me is our uh spongy moth treatment coordinator, John Larson as well. And so we just wanted to come before you today to share a little bit about spongy moth. Um my hope is that we'll uh share with you a little bit about what what is spongy moth, why the Department of Agriculture manages for this pest, uh the damage that it does cause to local environments, and then what our proposed management uh strategy is to assist here within the city of Rochester. And so we'll jump into it a little bit about spongy moth. Uh, we were just talking about this before we started uh this morning or this afternoon. Spongy moth was originally called gypsy moth. So if you're familiar with the term gypsy moth or have heard that uh uh pest in the past, this is the same pest, it's just got a name changed just a couple of years ago, and is now referred to as spongy moth. It is a federally regulated plant pest. So it's one of those pests that is uh it's an invasive insect pest that's introduced into the United States. It's not a pest that we want here, it's not a uh uh established, at least in the Minnesota, it is established in the United States back in uh the east coast uh back in the 1800s, and so it's moving kind of westward, and we'll talk a little bit about that, but it's an incredibly defoliating uh impacting insect, and what it does is it's it eats leaves on over 300 species of trees and shrubs. So it's a defoliator. So it's the caterpillar stage that's the most damaging, and this is a pest that will come out, and it has and that's the invasive nature of it, is the fact that it can feed on over 300 species of trees. So it has this really wide host range, and some of the preferred species of trees in which it prefers, particularly down in southeast Minnesota, is your oak. Um, oak, aspen, birch, willow, basswood, those are some of the preferred, but again, 300 species of trees. On average, annually, this pest is defoliating just under 800,000 acres annually across the United States where it is established. And back in 2023, just a couple of years ago, the state of Wisconsin had just under 400,000 acres in their state alone, defoliated, trees defoliated from this particular pest. Uh so it is definitely a damaging pest from both uh the environmental standpoint, but it also has some impacts to human health and impacts to potential property value due to mortality or trees dying uh due to stress. But some of the human health concerns is the large cat the caterpillars um break off, they have these very long hairs, and those hairs can break off into the ear and float around in air. And folks during outbreak levels, if they have sensitivities, asthmatic conditions, very sensitive people can have some um temporary responses to those. Other folks who handle the insects can potentially have some skin irritations uh with handling the caterpillars themselves. So uh the property value, this pest is not a tree killer. You may be very familiar with Emerald Ash borer, which is currently established here in the Rochester area and all through Southeast Minnesota. That is an invasive. That one is a tree killer. That one causes direct mortality to ash trees, where this particular invasive pest actually stresses trees, where it then leaves those trees vulnerable to other insects and diseases that then will move in, and that is what actually causes mortality. Just similar to Emerald Ashmore, it is a regulated plant pest, so it's not only regulated in the state of Minnesota, this particular pest is regulated nationally. It is currently only established in one-third its geographical range across the United States. We are protecting the spread of this insect into two-thirds of United States, basically the rest of Minnesota and two-thirds of United States that does not currently have this established pest. We partner with both the U.S. Forest Service on this and uh USDA uh Animal Plant Health Inspection Service to kind of slow and manage this pest across the United States. You may ask, okay, you just mentioned this pest was introduced back in the 1800s. Why is it not currently established in the rest of the geographical range in which it can be established? And that has to do with the biology of this insect. The female moth cannot fly. She has this incredibly large abdomen that's simply full of eggs. She will lay a single egg mass, and each egg mass contain between 500 and a thousand viable little caterpillars. So it doesn't take too many egg masses, too many females to have established populations. It is the male moth that has flight, and this is the male that we've been serving for some time, and I'll get into a little bit of our survey program. And that's the pest in which we we will be managing. Spongy moth naturally only spreads about a mile to a mile and a half naturally on its own across that, and the only way this insect can naturally move is when it's in its tiny little first instart caterpillar. It'll put a silken thread into the air and it will balloon or blow westward. So it relies on the currents of the wind to actually move it to new treetops to get established.