A caterpillar is basically a flexible tube…it is designed purely for eating and growing.
~Michael Chinery, in Butterflies and Day-flying Moths of Britain and Europe
Eat, poop, eat, poop…such is the life of a caterpillar. After BugFest, I kept a few of the specimens for a couple of days before releasing them back into the wild (where they were found) in order to observe and photograph them. The tough part of rearing caterpillars is providing them with enough of the right kind of food. It can get to be a full-time job if you have too many larvae living with you.
Some are picky eaters, like the Spicebush Swallowtail larva above (eats Spicebush and Sassasfras in our area), and feed on only one or two species of plant. Others are generalists, and can be found on a wide variety of plants, but some may prefer whichever plant species they were originally eating.
Whatever the diet, they tend to eat relatively little when small (first couple of instars). But, as they grow and molt, they really become eating machines. It is tough to find data on how many leaves one caterpillar can eat but one reference on monarchs estimated a single larva could consume all the leaves on a Common Milkweed plant by the time it was ready to pupate. Certainly, the last instar of a Monarch larva can consume 4 or 5 of the large leaves before forming a chrysalis. That’s a lot of food!
I love watching them munch through leaves. You can even hear larger caterpillars eating. So, in honor of the ending of another caterpillar season, I present a few short clips of caterpillars chomping on their larval lunches…