io moth

(Automeris io)

io moth
Photo by Bruce L.
  Hodges #

7746

 
 
Conservation Status
  IUCN Red List

not listed

     
  NatureServe

N5 - Secure

     
  Minnesota

not listed

     
           
           
           
           
 
Description
 
 

Io moth is a common, short-lived, day flying, medium to large-sized moth. It occurs in North America east of the Rocky Mountains, in Mexico, and in Central America. Adults are ¾ to 1 (20 to 35 mm) long and have a wingspan of 2 to 3 (50 to 80 mm).

On the male, the thorax is covered with yellow hairs. On the female it is covered with reddish-brown hairs.

The forewings of the male are bright yellow with dark brown markings. There is always irregular dark spotting on the reniform spot; a dark, jagged, interrupted, antemedial line; and a dark, scalloped, postmedial line that fades in the middle. There is sometimes a dark spot on the outer margin at the wing tip, dark spots along the subterminal line, and a broad dark area on the inner margin. The wingtips are pointed at an angle slightly greater than 90°. The forewings of the female are reddish-brown, dark, and more pointed, the angle slightly less than 90°.

The hindwings are mostly yellow with a large eyespot, a broad red area on the inner margin, and a thin red subterminal line. The eyespot is very large and black, with a gray or blue iris and a white pupil. It is surrounded with bright yellow and a has thin black line below. On the female the eye spot is larger and the subterminal line is wider.

First stage (instar) caterpillars are dark brown. Second and third instars are dull orange or orangish-brown. The fourth instar is tan or beige with a prominent stripe (spiracular stripe) on each side through the breathing pores (spiracles). The spiracular stripe is narrow, white, and bordered above by a thin, red stripe. The fifth (last) instar caterpillar is bright green, also has a thin red and white spiracular stripe, and is up to 2½ long. On the upper (dorsal) surface of each abdominal segment there is a tuft of pale green, two-branched (bifurcated), irritating (urticating) hairs. There is a similar but smaller tuft on the side of each segment.

 
     
 

Size

 
 

Total Length: ¾ to 1 (20 to 35 mm)

Wingspan: 2 to 3 (50 to 80 mm)

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Deciduous woodlands and forests, meadows, orchards, parks, and suburban areas

 
     
 
Biology
 
 

Season

 
 

One generation per year: Late May through June

 
     
 

Behavior

 
 

When handled, the irritating hairs on the caterpillar break of in the skin. The sting is similar to that of stinging nettle, but unlike with that plant, the sting lasts for hours.

 
     
 

Life Cycle

 
 

Eggs are laid on the leaves of host plants. Larvae pass through five stages (instars) in about four weeks. They overwinter in the pupal stage and emerge as adults the following summer. Adults live only one or two weeks.

 
     
 

Larva Hosts

 
 

Mostly leaves of deciduous trees and shrubs, including maple, oak, willow, hackberry, blackberry, and gooseberry; but also leaves of other plants, including corn and clover.

 
     
 

Adult Food

 
 

Adults are active during the day. They do not feed. The wings are held closed and flat when at rest. When disturbed they will quickly open their wings displaying the large, owl-like, eye spots on the hindwings.

 
     
 
Distribution
 
 

Distribution Map

 

Sources

21, 24, 27, 29, 30, 71, 75.

 
  9/6/2019      
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
 

Order

Lepidoptera (butterflies and moths)  
 

Suborder

Glossata  
 

Infraorder

Neolepidoptera  
  Parvorder Heteroneura  
  No Rank Ditrysia  
  No Rank Obtectomera  
 

Superfamily

Bombycoidea (hawk, sphinx, silk, emperor, and allied moths)  
 

Family

Saturniidae (giant silkworm and royal moths)  
 

Subfamily

Hemileucinae  
 

Tribe

Hemileucini  
 

Genus

Automeris  
       
 

Subordinate Taxa

 
 

io moth (Automeris io io)

io moth (Automeris io neomexicana)

 
       
 

Synonyms

 
 

 

 
       
 

Common Names

 
 

io moth

 
       

 

 

 

 

 

 

 

Glossary

Reniform spot

A kidney-shaped spot or outline in the outer median area near the postmedial line on the forewing of many moths.

 

Spiracle

A small opening on the surface of an insect through which the insect breathes.

 

 

 

 

 

 
 
Visitor Photos
 
           
 

Share your photo of this insect.

 
  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach one or more photos and, if you like, a caption.
 
 

Bruce L.

 
 

...released after pictures taken

 
    io moth   io moth  
           
    io moth      
           
 
MinnesotaSeasons.com Photos
 
 

 

 
           
           

 

Camera

     
 
Slideshows
 
 
     
     
     

 

slideshow

       
 
Visitor Videos
 
       
 

Share your video of this insect.

 
  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach a video, a YouTube link, or a cloud storage link.
 
 

 

 
     
     
       
       
       
 
Other Videos
 
  Io Moth (Automeris io)
KEYS MOTHS
 
   
 
About

Published on Dec 17, 2018

This video highlights the lifecycle of one of Florida's most impressive and dangerous insects. From false eye spots to stinging caterpillars, the Io moth is a fascinating insect.

 
  Caterpillar Sting Test
Quaoar Power
 
   
 
About

Published on Dec 5, 2012

http://www.facebook.com/quaoarpower Automeris io caterpillar sting in Mariposario Montezuma Gardens, Costa Rica

 
  Caterpillar: Io Moth (Automeris io)
IAmPolyphemus
 
   
 
About

Published on Apr 9, 2015

Phillip found this cool little guy the other day—a vivid green, fuzzy caterpillar with a red and white stripe. Some quick research revealed it to be an immature Io Moth. The “fuzzy” things are actually spines that can release a very painful venom, so it’s good we didn’t touch it :).

 
  IO Moth
Wild Clifton
 
   
 
About

Published on May 19, 2012

 
       

 

Camcorder

 
 
Visitor Sightings
 
           
 

Report a sighting of this insect.

 
  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Be sure to include a location.
 
  Bruce L.
7/6/2019

Location: Island Lake, Hubbard County

...released after pictures taken

io moth  
           
 
MinnesotaSeasons.com Sightings
 
 

 

 

 

 

Binoculars


Created: 9/6/2019

Last Updated:

About Us | Privacy Policy | Contact Us | © 2022 MinnesotaSeasons.com. All rights reserved.