Monarch Caterpillar food at Raccoon Creek State Park

Monarch caterpillar photographed by Jeff Zablow at Raccoon Creek State Park

With the volume of discussion  about the limited numbers of Monarch butterflies this year in the northeast and beyond, we’re sharing Monarch images and taking queries on the butterfly and its caterpillar life cycle.

Some years ago, working with Carnegie Mellon University, I produced a multimedia presentation about butterflies. Included in it was an interview with a professor emeritus of Chemistry. I included a question asking him, “What are the actual sugars in the nectar of wildflowers?” To my surprise, he said he didn’t know the answer to that question. That’s one of several thoughts I had that brought me to make this post on a Monarch caterpillar.

This Monarch butterfly caterpillar has already secreted the substance that will enable it to continue pupating.  The white material will hold the pupating larva fast to the stem that supports it. You better believe that  it’s critical that the binding materials does not fail.

What is the chemistry of that material? How does the caterpillar produce it? What is it formed from? Have there been any commercial applications that employ that material and process?


An Orange Sulphur Butterfly Feeding at the Juice Bar in Raccoon Creek State Park

Orange sulfur Butterfly photographed by Jeff Zablow a Raccoon Creek State Park, PA. Jeff blogs about the art and science of butterflies at

One of the most difficult of the Eastern U.S. butterflies to photograph (macro-) this Colias eurytheme. Most of the time we cannot tippy-toe up to them–they speed away once you are 10 feet away from them. Their escape flight is usually just 2 feet above the ground and generally to a landing 40 feet away!

This one though is at the juice bar, sipping at Red Clover (Trifolium pratense). Red Clover must be especially tasty. It’s visited by such a variety of butterflies and bees. While this Orange Sulphur butterfly was feeding at Raccoon Creek State Park in September, our very careful approach was tolerated.

Funny about things . . . Orange sulphurs migrated eastward from western states in the 1920’s and red clover was an alien wildflower, introduced from Europe. Neither were found east of the Mississippi when George Washington became our first President.

During this past winter, which carried this species through to Spring? Adult, Larva or Pupa or Egg?