Naturally Speaking: I wish I could brake for butterflies

Steve Lekwa

I ran outside with the camera the other day because I’d seen something unusual out in the yard. What was so unusual? A tiger swallowtail butterfly was feeding on my marsh milkweed flowers. It was exciting and sad, because this once-common sight is now noteworthy. While trying unsuccessfully to capture the rapidly moving swallowtail, I noted several great spangled fritillary butterflies feeding on the same flowers. I was able to get some nice shots of these orange-and-brown butterflies, with silver spangles under their hindwings. I even got a couple of shots of a lone monarch who stopped briefly for a snack. It wasn’t long before the garden was empty again, and I saw no more butterflies that day. I have always loved to see butterflies, but, like most people, I didn’t consider how really special they were when they were so common years ago.

Thankfully, we can still find butterflies to enjoy, but now we may have to look for them in special places like Doolittle Prairie south of Story City or some other larger natural area remnant like the woods along the Skunk River Greenbelt to see them. Most adult butterflies feed on flower nectar from a variety of plants, but a few like orange-and-brown commas and question marks and the red-spotted purples also gather nutrients and fluids from sources like fresh dung and rotting fruit. Butterfly larvae, caterpillars, often feed on only a few kinds of plants. Some are so specific that they eat only one specie of plant. The following paragraphs introduce some, but far from all, of the butterflies you might still see locally if you look for them in the right places.

Everyone can recognize a large orange-and-black monarch butterfly if they see one. Precipitous declines in their population has raised national alarm, and nationwide programs are being instituted to keep them from vanishing completely. Time will tell if crash programs to plant more milkweeds for their caterpillars can head off the approaching disaster. A few “smaller monarchs” are more likely viceroys, whose caterpillars feed on willow and poplar trees.

Swallowtails are large and showy. The black swallowtail shows small yellow spots on black wings. Its young feed on plants in the parsley family. The Eastern tiger swallowtail is large and bright yellow with black “tiger” markings on the wings. Its young feed on cottonwood, various cherries, and other trees and shrubs. The biggest of them all, the giant swallowtail, is primarily black above with bold rows of yellow spots and primarily yellow below with black markings. Its young feed only on plants in the citrus family. In our area, that’s represented by the prickly ash alone, a woodland shrub.

Sulphur butterflies are represented by the clouded sulphur and orange sulphur. Both are smaller and basically yellow above and below, with the latter being slightly more tinged with orange. They both show a black boarder around their wings. They were once seen in clouds over legume hay fields, but have declined in numbers since hay fields are now rare in our part of the state. They’re still here because their young can feed on other legumes. Similarly sized cabbage whites are basically white with a few darker spots. The young of this European import feed on plants from the cabbage and mustard families. That’s the small green caterpillars often found in our gardens.

The mourning cloak is a large woodland butterfly, with deep brown wings edged with yellow. They’re unusual in that they winter over as adults and can sometimes be seen flying on warm winter days. Its caterpillars feed on a variety of trees, including cottonwood, willows, elms and hackberries. Common wood nymphs are smaller brown woodland butterflies with yellow spots on the upper forewings and dark “eye spots” on the underwings Their young feed on grasses.

Skippers are a large and complex family of mostly little brown and orange butterflies. They’re fast fliers and many relate to specific host plants. Even butterfly specialists struggle to sort them out. Other delightful little butterflies include the azures that can sometimes be seen fluttering around puddles, blues and gray hairstreaks.

It’s not hard to understand why butterfly numbers have dwindled. Habitat loss and the resulting loss of food plant diversity have played significant roles in declining populations, just like it has with many other once-common birds and animals. Iowa’s landscape has become less diverse, and more than 50 years of pesticide use factors in as well. Some people show what they like with a bumper sticker saying “I brake for ____”. Although I’d probably cause an accident if I did it, I’m tempted to put on one that says “I brake for butterflies.”

Steve Lekwa is a former director of Story County Conservation.