We often notice where there are a lot of a particular kind of insect around, and not as much when there are fewer present. But in the case of butterflies, we definitely notice their absence, and this year they have been scarce.
Phil Pellitteri is an entomologist and head of the UW-Madison Insect Diagnostic Lab. He says that with one hundred and fifty species of butterflies in the state, it’s not a one size fits all answer. For example, last year’s drought conditions stressed the butterfly population and affected the southern migrants that come up to Wisconsin. And this year, we are still seeing the lingering effects of those extreme conditions. The butterfly populations crashed, and it often takes more than a year for them to recover.
Pellitteri says that he has recently started seeing some Monarch activity and the appearance of a few Swallowtails, “but overall, if you’re a butterfly person, this has not been a good year.”
There is additional concern for the Monarch butterflies because their wintering grounds are so concentrated. The story of the Monarch migration is incredible, especially when you take into account the tiny and delicate creatures that make that trip.
While this year’s sessions are full, the Natural Resources Foundation of Wisconsin offers several field trips each year during which participants can help researchers by tagging migrating Monarchs. You can see photos from one of those field trips here.
If you are seeing butterflies this year, it’s likely to be a small, white butterfly hovering over garden areas. Pellitteri says that it’s the imported cabbage worm butterfly. They come from the small green worms that feed on the leaves of broccoli and other cruciferous vegetables. Pellitteri says that they seem to be having a good year, and will go through as many as three generations in a single season. While they are not as flashy as some others, the lack of more colorful species makes them stand out more than usual.
Pellitteri recommends Mike Reese’s Wisconsin Butterflies site as a great resource for learning more about butterflies and identifying those you see in our state. The site includes information on where particular species are found, but also when they fly, and even weekly reports of sightings around the state.
