Don’t be alarmed if you’re near a fruit tree and lock eyes with a 5-inch-long giant green caterpillar lined with bright blue, orange and yellow spots.
It will soon become a cecropia moth, a red and brown-spotted moth that is the largest native to North America. The leaves caterpillars eat now will feed them for the rest of their lives. The moths have no mouths and live off of body fat stored from their time as caterpillars before dying within two weeks.
The caterpillars, part of the giant silk moth family, often feed on maple leaves, but you may find them on plum, apple or wild cherry trees. Alder, willow, dogwood, birch and box elder trees can host them too.
The caterpillars are unusual, though not rare, and their populations are scattered enough that they won’t cause significant damage to established plants, so you can leave them unharmed.
As adults, the moths have wingspans of more than 6 inches.
To become these large moths, they will build cocoons that are also unusual. Several years ago, the BDN sought reader feedback to help identify a brown sac woven with dry grass in a picture sent in by a reader.
Before it was identified, readers suggested it might have been a miniature woodland coconut, a gnome nest or an egg case of the mythical chupacabra.
The caterpillars that emerge go through several cycles, becoming bigger and greener as they go.
If the giant green caterpillar on your trees doesn’t match this description, it could also be a stage of the luna moth. That moth is also quite large, though smaller than cecropias with a wingspan of about 4 1/2 inches. As caterpillars they are more segmented and have red-orange dots, not the blue and yellow highlights of cecropias.
Of course, there are tomato hornworms too — those hefty green caterpillars eating through your plants, later to become five-spotted hawk moths. Before you see them, you might see the cube-shaped waste they leave behind.
Other species in the sphinx moth family start as similar chunky green caterpillars.
