Monarch butterflies may rule our hearts, and perhaps our days, with their striking colors and charisma, but moths rule the night. These night-flying relatives of our beloved day-flying butterflies are often overlooked for their more flashy cousins. It’s easy to overlook things that only (or mostly) come out at night, and are usually small and very well camouflaged.
Our education team in Minnesota is on a mission to change that. Moths and butterflies do share habitat, though they aren’t normally seen at the same time (with some exceptions). Moths pollinate night-blooming flowers in particular (such as evening primrose), but they also use many native plants as host plants. For example, 115 species of moths and butterflies use goldenrod as a larval food source. There are many species of goldenrod that also support bees, beetles, grasshoppers and other insects. These moth and butterfly caterpillars are also an important food source for nesting songbirds! Even if the songbirds eat seeds as adults, their young are raised on insects.
We hosted our first Moth Ball on April 18th at our Prairie Oaks campus in Belle Plaine, MN. So what did we discover? The short answer: a lot more than we expected! In true midwestern fashion, the weather forecast for that night changed about 10 times in the week leading up to the program, but that morning the forecast said the evening was going to be cloudy, cool, and breezy. In fact, we had to rethink a few times about where to hang our sheets for the light traps, and get a little creative with how we kept them from blowing away.
Finally, after much trial and error and fighting with the wind, our light traps were set. We placed two different kinds of lights on a vertically hung, white sheet — one light was a heat lamp for reptile enclosures and the other was an LED work light. Our other light trap was created by hanging a white sheet in a tent over a rope strung between two trees, then we placed two UV black lights underneath, one facing each side. Finally, Cory Kragness, one of MJVs remote sensing field techs with a love of moths, set up their light box trap. They made this themselves, using a plastic tote bin, a funnel, a 4,000-lumen lamp, and some torn-up egg cartons inside for the moths to rest.
We also mixed up some bait with brown sugar, mashed bananas, and stale beer, which was then spread on trees around where we were collecting moths.
Twelve participants joined us. We started with some information about moths - what makes them different from butterflies, how to ID them, what to do when we catch them - before heading outside to check our light traps.
And once again, Minnesota reminded us why flexibility is important when it comes to spring weather. The minute we stepped outside it started to rain. Thankfully it was a soft rain, so we continued with our plan. We pulled out our raincoats and umbrellas, and walked forth equipped with red flashlights, collection jars and boxes, hand lenses, field guides, and a strong curiosity to see if we’d still find moths. Moths don’t seem to be as deterred by cold wet weather as their daytime counterparts, so we were hopeful. And we know that flying moths can be seen year-round in Minnesota, if you know where and how to look for them!
It started out a bit rocky, not seeing much besides some midges and male mosquitoes (also pollinators!). We weren’t sure if it was because of the weather or the recent sunset. We kept making the rounds to each of the traps, and soon decided to take down the lightbox, as it was more susceptible to the rain. Shortly after, one group member found our first moth! Hooray! They seemed to like the bait more than the lights at first, but as the rain slowed, we started to see more on the sheets.
That night we saw a few white-specked moths, some male mosquitoes (not a moth, but still a pollinator!), and several other species we couldn’t identify beyond their family. This included several superfamily Noctuidae (or Owlet moths) and the superfamily Geometroidea. Noctuidae are the largest group of moths, are mid-sized (2-5 cm wingspan), with a triangular, stout body shape. Geometroidea are about the same size, but usually have their angular wings held open like butterflies (fun fact: their larvae are what many of us know as inchworms!)
All of our sightings were uploaded to iNaturalist. Our helpful guides (apart from iNaturalist) included the Field Museum’s Beginners Guide to Moths of the Midwest series, Moths and Caterpillars of the North Woods by Jim Soggard, and Peterson Field Guide to Moths of Northeastern North America.
We are hosting two more Moth Balls this year: July 11th and September 12th. Click on the links to register. We hope you’ll join us to see what more we will find!
