One of my favorite things about my job is that I’m always learning something new. While much of what I learn might not be enough to justify an entire blog post dedicated to it, I still feel it’s cool enough that I want to share! So here’s a new type of blog post – a monthly collection where I offer up some tidbits of fun information that I’ve gleaned from my recent education adventures.
The secrets of caterpillar poop
Early August, I was watering my herbs, and suddenly noticed a few friends among my parsley – 10(!) black swallowtail caterpillars were busy munching and growing amongst the stems. My two daughters were completely enamored and begged me to bring a few inside to watch their transformation to butterflies. We quickly gathered materials for a butterfly habitat (I found a great how-to here) and within an hour we had brought two of the largest caterpillars inside.
Over the next several hours, one thing became clear – caterpillars poop a LOT. Suddenly the habitat had little black pellets covering the bottom as the caterpillars continued to munch on leaves. I went back outside, and found similar frass (what their poop is technically called) all over the planter walls next to the parsley. For something so small, caterpillars defecate a surprising amount.
Caterpillar frass can, like other types of poop, act as a great fertilizer to their host and surrounding plants. Awesome. I swept all the frass I could see back into my herb garden. What I found even more interesting, though, is that in looking up ‘caterpillar frass,’ I came across an article that talks about how different caterpillars can use their frass to trick their host plants. Armyworms, for example, are a huge pest to corn crops and can greatly impact corn yields. As they munch on the leaves, their frass drops to the ground and actually releases a chemical that tricks the plant into thinking that it’s being attacked by a fungus versus a herbivore. A corn plant then deploys its fungal defense versus its bug defense, and since it’s wrong defense, the armyworm is able to happily keep munching away.
Poop can be tricky. Just bizarre.
And yes, by the way, all of our caught caterpillars successfully transformed into butterflies and were released back to nature!
Want to help build more pollinator habitat? Lawns to Legumes are again accepting applications! Recipients can get up to $350 for pollinator habitat projects. The application period is open until January 23rd, 2023.
Connecting snail shells to water quality
This past Tuesday evening, I joined Jessica Lindemyer, outreach coordinator for the Comfort Lake Forest Lake Watershed District, to help run her weekly booth at the Forest Lake Arts in the Park. The theme? The plants and bugs of Forest Lake.
Armed with a few plastic tubs and a kick net, my daughters and I dredged a couple areas near the shoreline among the shoreline vegetation trying to find water bugs. While initially the water was too cloudy to see anything, a few minutes later the aquatic macroinvertebrates revealed themselves dashing through the water as the sediment settled in the tubs. We quickly grabbed our plastic spoons and started scooping up little creatures into sections of an ice cube tray for further viewing and study for those at the park.
Aquatic macroinvertebrates form the base of the aquatic food web, and the amount and the types of creatures you find can tell you a lot about the health of a lake, river, or stream. There are some species that can only survive and thrive in clear, clean water with little pollution, and some who can survive in whatever conditions you’ve got – polluted or not.
In our quick grab samples from Forest Lake, one of the most obvious specimens we collected were several large empty snail shells. Given that the shells float when its occupant passes away, they are easy to see and fun to grab. What’s not as obvious however, is that one can determine what type of snail you have based on whether the shell opening points to the left or the right. If the opening points to the left, you have a pouch snail that breathes air through its lungs. If you have a shell whose opening points to the right, you have a gilled snail that uses gills to breathe underwater.
Creatures that rely on gills to breathe are going to be much more intolerant and sensitive to cloudy, polluted water. Thus, having ‘right-handed’ snail shells in your lake or stream is a good sign that you have good water quality. Luckily, the majority of the shells we picked up at Forest Lake were all ‘right-handed.’ And that assumption of good water quality was further backed up by the presence of other gilled macroinvertebrates in the water, including mayfly and damselfly larvae.
Good on you, Forest Lake!
Aquatic bugs also need good shoreline habitat to thrive. While we might want to rid our shorelines of ‘weeds,’ aquatic vegetation helps hold up the aquatic food web! Learn more in my colleague Angie Hong’s post about how we tend to love our lakes too much.
I soiled my undies. And I’m quite pleased with the results.
If you’ve been following this blog at all, you know that I’ve been taking a bit of a native plant journey this spring and summer, and part of that journey has looking at the health of my garden soil. While I did send in a soil sample to be formally tested, I also decided to take part in a more…eye-catching(?) soil health experiment after attending our first production ag field day in June.
The demonstration, called ‘Soil Your Undies’ involves placing a a new pair of men’s cotton briefs in a hole in your garden (vertically so the elastic strap is still visible), burying it, and then waiting 60 days.
The state of deterioration of said undies over the 60 days gives a decent measure of how active your little soil microbes are (ya know, those microbes that are integral in nutrient cycling, breaking down residue, and stimulating plant growth). The more deterioration of the undies = the more microbes you have = healthier soil.
After planting them in late June, I dug up my undies a couple days ago. I gotta say, they deteriorated much more than I thought they would! My soil is doing good!
Speaking of field days, we’re having another production ag field day near Rush City THIS coming Tuesday, August 30th. Host Lance Petersen is going to talk about his experiences with strip till and we’re excited to hear from other local farmers who practice no-till and conservation tillage. We also have a great extended interview with Lance from just a couple weeks ago. See the teaser below and watch the full interview here.