Of Prairie Wildflowers and Wily Weevils

“If I had my way, I’d remove January from the calendar altogether and have an extra July instead.” –Roald Dahl

We need…rain. I keep looking to the skies for any sign of it. No luck.

What we will see on Wednesday is the full “Super Buck Moon” , sometimes called the “Thunder Moon”. On Monday, not quite at peak, it was still stunning.

Almost to full moon over Crosby’s backyard prairie, Glen Ellyn, IL.

Despite the lack of rain, the prairie pours out flowers.

Leadplant (Amorpha canescens) and prairie cinquefoil (Drymocallis arguta), Schulenberg Prairie, Lisle, IL.

Acre after acre of wildflowers.

Leadplant (Amorpha canescens), prairie dock (Silphium terebinthinaceum), new jersey tea (Ceanothus americanus) and other prairie species, Schulenberg Prairie, Lisle, IL.

Not all is going smoothly in the grasslands, however. This is the season of the wonderful, wild, and wicked weevils. Two of the prairie’s evil weevils merit special attention: the sunflower head-clipping weevil and the wild indigo weevil. Let’s turn our attention first to the sunflower head-clipping weevil.

Compass plant (Silphium laciniatum), Schulenberg Prairie, Lisle, IL. (2020)

Looks innocent, doesn’t it? Then —see that compass plant with its flowerhead chopped off? 

Compass plant (Silphium laciniatum), Schulenberg Prairie, Lisle, IL.

That’s a signature weevil move. How about that prairie dock bloom? Or…was in bloom.

Prairie dock (Silphium terebinthinaceum), Schulenberg Prairie, Lisle, IL.

Yup, the wily weevil was at work again.  Sometimes known by its nickname, “the head clipping weevil,” its scientific name is almost-almost!–unpronounceable: Haplorhynchites aeneus. Our wicked weevil is black, and about ⅓ inches long with a long, curved schnoz. Rather than knifing through the flower itself, the weevil severs the stem below the flower head. After the weevil applies the guillotine and girdles the flower’s peduncles (try saying that fast three times), the resiny sap of the compass plant bubbles to the surface and glistens in the sunshine. You can see the resiny sap on the plants in the winter, too, but it’s more crystalized.

Compass plant (Silphium laciniatum), Belmont Prairie, Downers Grove, IL (November 2021)

Now, swipe your finger over that sticky sap, and you’ll get a taste of Native American chewing gum. Note: Don’t get the resinous sap in your hair. If you do, you’ll star in a completely different kind of episode of “Chopped.”

White wild indigo (Baptisia alba) and brown-belted bumblebee (Bombus griseocollis), Schulenberg Prairie, Lisle, IL.

The sunflower head-clipping weevil is only one of many weevils on the prairie. The wild indigo weevil (Trichapion rostrum) is in the Family Brentidae, a group of straight-snouted weevils. This family is currently in flux—entomologists still haven’t decided who exactly is in it (#entomologicaldilemmas). This is a hungry, hungry weevil, which we find in the fall inside pods of white wild indigo. At only a quarter of an inch, the wild indigo weevil is (wait for it) the “lesser of two weevils.” (Da-da-dum).

Wild indigo weevils at work on white wild indigo seed pods, Schulenberg Prairie, Lisle, IL. (2021)

Weevils have many devoted fans. There are weevil blogs, weevils websites, and weevil specialists. You could say that weevils are some of the stars of the insect world! I’m glad they specialize. Imagine if they cut the flower heads off of all prairie flowers. Yikes!

Prairie milkweed (Asclepias sullivanti), Schulenberg Prairie, Lisle, IL.

It’s bad enough they attack some of the sunflowers and some of the coneflowers. Destructive? Yup. Fascinating? Absolutely. Perhaps the most famous weevil is the Boll Weevil (Anthonomus grandis), featured in Elvis Presley’s song, “Little Sister.” Rock on, weevils! But leave some of the other prairie wildflowers to the bees and other insects, okay? 

Butterfly milkweed (Asclepias tuberosa), Schulenberg Prairie, Lisle, IL.

Who knows what other intriguing insects you’ll find in the tallgrass this week?

12-spotted skimmer (Libellula pulchella), Schulenberg Prairie, Lisle, IL.

Wildflowers, too.

Illinois tick trefoil (Desmodium illinoense), Schulenberg Prairie, Lisle, IL.

Why not go for a hike and see what you discover?

*****

The opening quote is by Roald Dahl (1916-1990), a British spy, fighter pilot, and the author of James and the Giant Peach, Charlie and the Chocolate Factory, Matilda, and Chitty Chitty Bang Bang.

*****

Join Cindy for a class or program this week!

Last call for Beginning Dragonfly and Damselfly ID offered as a blended class through The Morton Arboretum in Lisle, IL! Join Cindy on Zoom Thursday for an introduction to the fascinating world of dragonflies and damselflies. Then, meet your class on the prairie to discover some of these beautiful flying insects. Register here.

****

Thanks to Teri P. for the Elvis Presley reference, and to the following sources on weevils: The Smithsonian online, the Chicago Botanic Garden (great blog post! check it out), North Carolina State extension, Wikipedia, and the Kansas State Extension, and many prairie mentors over the years who loved the “lesser of two weevils” pun, and shared it with me. I laughed every time.

2 responses to “Of Prairie Wildflowers and Wily Weevils

  1. Cindy – what is the reason the weevils cut around the stem? Do they feed off the resin?

    Liked by 1 person

    • Hi Paula — Great question! I believe they only eat the flower pollen. Not sure why they decapitate the bloom! A good question for any entomologists reading this post (jump in!) — Cindy 🙂

      Like

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