io moth

(Automeris io)

               
Hodges #

7746

io moth

 

Conservation Status

IUCN Red List

not listed

NatureServe

N5 - Secure

Minnesota

not listed

Occurrence

Common

Flight/Season

One generation per year: Late May through June

Habitat

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

Size

Total Length: ¾ to 1 (20 to 35 mm)

Wingspan: 2 to 3 (50 to 80 mm)

         
          Photo by Bruce L.
 
Identification

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.

 
Similar
Species

 

 
Larval Food

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.

 
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.

 
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.

 
Distribution Distribution Map  

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

 
Comments

 

 
Taxonomy

Order:

Lepidoptera (butterflies and moths)

 

Suborder:

Glossata

 

Infraorder:

Neolepidoptera

 

Parvorder:

Heteroneura

 

No Rank:

Ditrysia

 

No Rank:

Obtectomera

 

Superfamily:

Bombycoidea (hawk-moths)

 

No Rank:

Saturniiformes

 

Family:

Saturniidae (giant silkworm and royal moths)

 

Subfamily:

Hemileucinae

 

Tribe:

Hemileucini

 

Genus:

 

 

Subgenus:

 

 
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 costal margin on the forewing of many moths of the Noctuidae family.

 

Spiracle

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

 

 

 

 

 

       
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Bruce L.
       

...released after pictures taken

  io moth   io moth
       
  io moth    
       
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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
   
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Bruce L.
7/6/2019

Location: Island Lake, Hubbard County

...released after pictures taken

io moth


     
     
 
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Binoculars


Created: 9/6/2019

Last Updated:

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