There is an old saying you may have heard your grandparents use that goes like this, “Snug as a bug in a rug.” This comment might be used on a cold winter day when you are inside and warm and comfortable. It means you are safe and secure from outside threats.
That old saying comes to mind when I think about today’s Naturalist’s Notebook topic. Leaf roller moths and their caterpillars.
I love butterflies and moths, and I often challenge myself to see if I can find caterpillars. I’ve done this ever since I got interested in insects during my elementary school years.
I have learned it is far more difficult finding most caterpillars. Much harder than finding the adult moths.
Leaf rollers are different. They offer a really great clue to help a young scientist find them. They do exactly what their name says. These small little caterpillars hide from predators like wasps, birds, lizards, or spiders by rolling themselves in a leaf. All you have to do is observe very carefully and look for these rolled leaves. I am including a couple of photos to help give you an idea what they look like.
Using silk glands in their heads, they spin sticky silk to start curling the edge of a leaf until it is a tube, with them inside. Then, snug as a bug in a rug, the small caterpillars can eat and sleep in comfort and safety.
It turns out there are lots of different varieties and different caterpillars eat different plants. I have found them on elm, oak, maple, hickory, ash, hazelnut, grape, and blueberry.
Until this spring I never knew exactly what the adult moths of these caterpillars looked like.
My black light sessions attract lots of moths to my white sheet. The photos I take of even the smallest of moths have finally allowed me to meet the adults. An app on my cell phone called iNaturalist helps greatly with their identification. I submit a photo and the app gives me possible choices of similar-looking species.
Those little caterpillars become very small and very attractive moths. Most are only about 1/4 inch long.
My favorite is the White-Spotted Leaf roller Moth. It is a burnt orange color with round white dots around the edges. For some reason, every time I see one, the round white spots remind me of balloons at the circus.
Another that I often see is the Broken-banded Leaf roller Moth. It is yellowish-tan with slanted brown markings.
The easy-to-identify black moth with white spots and slender wings uses grape leaves as a caterpillar food and hiding place. It is called the Grape Leaf Folder Moth.
The one with an orange, squiggly, net-like pattern is the Yellow-winged Oak Leaf roller Moth. This is probably what the little green caterpillars I’ve found when I unrolled oak leaves turn into.
Finally, the shiny yellow moth is the Maple-Basswood Leaf Roller Moth. I found these caterpillars on red maples in my woods. It must have some specially constructed scales that give it that shiny look, like plastic.
If you find a rolled-up leaf and very carefully unroll it, you may find one of the caterpillars. Don’t disturb it too much. It will use silk to repair and roll up its home leaf again after you leave.
If no caterpillar is at home, it probably means it has already dropped to the forest floor and changed into its next life stage, a cocoon.
Have fun searching for leaf rollers!