Skip to main content
Flowers, Fruits, and Frass

Butterflies Adapting

Illinois Butterfly identification programs have been popular among the prairie walkers and flower gardeners. It is these delightful visitors of flowers or tree sap or in some cases dung and mud puddles that capture our interests and cause us to ask "What kind of butterfly is that?" and "Where did it come from?" and most of all "How do I lure them to my garden?" In my ventures to understand and identify butterflies, I have come to one very apparent conclusion. "Butterflies have developed amazing adaptations to survive nature but also need certain conditions to thrive," states University of Illinois- Livingston-McLean-Woodford Horticulture Educator, Kelly Allsup.

The red-spotted, purple caterpillar must defend itself from foraging ants in its early larval stage. It protects itself by building a frass stick in which it can perch off the edge of a leaf. The frass stick is built out of the two things it has most available, silk from the spinneret and frass (insect poop.) When the tiny caterpillar senses vibrations on the leaf or needs to take a break it crawls to the end of the frass stick to rest. Doug Tallamy, entomologist from University of Delaware and famed author of "Bringing Home Nature" says "Apparently, ants would rather go hungry than walk out on a stick made of frass."

Many Illinois butterflies avoid detection of predators by blending in with its background. The very green Clouded Sulphur butterfly caterpillar feeds and hangs out on the middle vein of the leaf going mostly unnoticed. Then when the caterpillar gets bigger, it turns bright yellow to blend in with the flowering partridge pea. The chrysalis also can take on the yellowish hue to blend in.

The spicebush swallowtail is one of the best adapters using camouflage to avoid detection throughout all of its life stages. Early caterpillars look like bird poop and later stage caterpillars look like small green snakes with large eye marks. The eye marks are on the abdomen end in case a bird tries to take a nibble it will not be eating the head. The chrysalis looks like an insignificant brown leaf and the adult butterfly mimics the poisonous pipevine swallowtail.