Wednesday, November 26, 2008

Io Moth Caterpillars

I have a million little caterpillars eating my coconut palms. They are the larval form of the beautiful Io Moth. I find them from time to time throughout the year. It is found throughout most of America east of the Rockies. The adult Io Moth has a wingspan of 2.5-3.5 inches. This species is sexually dimorphic, males having bright yellow forewings, body, and legs, while females have reddish brown forewings, body, and legs. The males also have much bigger plumose (feathery) antennae than the females. Both have one big black to bluish eyespot with some white in the center, on each hindwing, a defense mechanism meant to frighten off potential predators. [1] We have our own subspecies here in Florida Automeris io lilith and the males have a distinct red-brown forewings. The same type of red form is also found in southern Mexico and the Bahamas. Io moth larvae are leaf feeders, gregarious in early instars, then solitary as they grow. After several weeks of feeding, they make a simple paper-like cocoon away from the host plant. In Florida, there are three to four generations per year. There usually is only one generation in northern states. [2]
The io moth has a long list of host plants, with over 100 recorded plant genera in North America, including such diverse plants as roses, cotton, hibiscus, azaleas, willows, clover, and palms. In Florida, io moth larvae are commonly found on oaks and other hardwoods. [3] I'll say let's go ahead and add Coconut (Cocos nucifera), as a larval food in Florida!!!!

Early instar larvae of the io moth, Automeris i0 11-26-2008

Second instar larva of the io moth caterpillar, Automeris io 12-10-2008

Final instar larva of the io moth caterpillar, Automeris io

Adult Io Moths Female(top)and male(below)
photo courtesy of
Original photo by Patrick Coin

Family/Subfamily: Saturniidae/Hemileucinae •
Genus: Automeris
Species/SubSpecies: io/lilith
Common Names: Io Moth •


Creative Commons License
Io Moth Caterpillars by Eric Bronson is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
Based on a work at


Anonymous said...

gosh those are beautiful, I have thing for moths. I had never seen one before!

Sunita said...

Those moths are beautiful! So how come they have such scary looking babies? The orange ones with bristles would have me running a mile!

Muddy Mary said...

It is good to see so many of them in your photos. When I was a kid (that was at least a couple decades ago) they were abundant--to my mom's dismay. Now I see maybe Io caterpillar a year.