Hello, young scientists! Today’s Naturalist’s Notebook topic is about giant silkworm moths. They are the very largest insects you can see around lights at night. And some live right around here!
I’ve been having a lot of fun setting up an ultraviolet light hung in front of a white sheet at night. This is known as black lighting. The light attracts many insects that fly at night. I’ve met lots of beautiful and interesting moths I would never have seen during daylight hours.
While most moths are small, the giant silkworm moth family has some of the largest moths in the United States. It is always a thrill to see one of the really big ones!
I’ve suplied photos of two that have visited my light this spring. The very pretty light green Luna Moth has extremely long tails on its hindwings and wings that spread 4 or 5 inches across, making it one of the most memorable and spectacular moths you may ever see.
If you’ve ever been to one of my Tennessee Aquarium “Insects Around Us!” outreach programs at your school or public library, I’ve shown you a specimen of the Indian Moon Moth. This moth from halfway around the world is very closely related. It is a bit larger, looks similar, and is the same color as our Luna Moth.
Like other moths and butterflies, giant silkworm moths go through four life stages: egg, larva (caterpillar), pupa (cocoon), and adult.
Their caterpillars get big and fat. This is important because the adult has no mouthparts. They do all their eating while they are caterpillars!
Luna Moth caterpillars feed on many types of common trees that you could find in our area. Alder, beech, cherry, hazelnut, hickory, pecan, sweet gum, and willow are all host plants they use. I have four of those eight trees in the woods around my house.
The large light brown moth is the Tulip Tree Silkmoth, and its wingspan is even bigger than the Luna. I was lucky to get photos of both the top and bottom of this one. As you might guess, the official Tennessee state tree, the Tulip Poplar, is on the menu for their big green caterpillars. They also like black cherry and sassafras. All three of these trees live near me.
To get to know different types of trees, a fun activity would be making a leaf collection. Gather leaves of plants and trees around your neighborhood. Remember my blog about poison ivy, and don’t include its leaves. “Leaves of three, let it be!”
Spread out the green leaves you’ve collected between the pages of an old book and put something heavy on it to squash them flat and let them dry. In a week or two, they will be dried and flattened, and you can glue them on a page of your leaf collection book. Then it is “Google time” on the internet to try to figure out what you found. I recently discovered a leaf collection I put together in elementary school, and it was still in good shape!
Giant silkworm moths are very attracted to lights, maybe even the lights on your front or back porch. You might walk out one evening and find one of these beauties flying about or resting on the wall near the light. I hope you see one.
If a giant silkworm moth should come to visit, leave it alone, and admire it without bothering it. They live only about a week as an adult. (Remember, they can’t eat.) In that time, they must find a mate so eggs will be laid to start a new generation of super-large, super-beautiful moths.
I’ll introduce you to other neat moths in a future blog, including one I met for the first time last night—the Batman Moth!