sigmoid prominent

(Clostera albosigma)

               
Hodges #

7895

sigmoid prominent
Conservation Status

IUCN Red List

not yet assessed

NatureServe

N5 - Secure

Minnesota

not listed

Occurrence

Common

Flight/Season

Mid-May to mid-August. Probably two generations per year.

Habitat

Deciduous woodlands and forests, and shrubby wetlands and fields

Size

Total Length: to ¾

Wingspan: 1 to 1½

          Photo by Bill Reynolds

Identification

This is a medium-sized, heavy-bodied, nocturnal moth. It is the most common of the four Clostera species found in Minnesota. The species name albosigma means “white S” and refers to the prominent curved marking on the forewing. Spring individuals are darker with more highly contrasting markings. Summer individuals are paler and less conspicuously marked.

The top of the head, the collar, and the top of the thorax are dark brown. The rest of the body is lighter grayish-brown. The male has a dark brown tuft at the tip of the abdomen.

The forewing is grayish-brown. The forewing is slightly concave on the costal (leading) margin and is rounded at the tip. It is crossed by four pale lines, the basal, antemedial, median, and postmedial lines. The antemedial and median lines are parallel and nearly straight. The median line is broken and does not reach the costal margin. The postmedial line is angled backward, forming a “V” with the median line at the inner margin, and forming a prominent white “S”-shaped bar approaching the costal margin. The white bar sharply delineates a dark reddish-brown or chestnut brown area. The cubitus (Cu) vein appears 3-branched.

The hindwing is nearly evenly grayish-brown without contrasting markings. The subcostal (Sc) vein and the anterior branch of the radius (R1) are fused together. The Sc+R1 and radial sector (Rs) are close together and parallel to at least the basal half of the anterior side of the discal cell then diverge.

The male antennae are comb-like with teeth-like structures on both sides. The female antennae are thread-like.

The caterpillar is stout and up to 13 16 long. It has a dark, proportionally large head, and there is usually a pale brown spot above the face (frons). The thorax and abdomen are yellowish-buff and covered with downy, pale hairs (seta). Between the first thoracic segment (T1) and the second abdominal segment (A2) there are four indistinct orange or yellow lines separated by even more indistinct charcoal lines. There is a black knob on A1 that is nearly twice as large as a similar knob on A8. There is a broad, dark gray subdorsal stripe and a broad orange spiracular stripe. Mature caterpillars are seen from May to November.

 
Similar
Species

 


Larval Food

Mostly quaking aspen, but also poplar and willow, and sometimes alder, birch, maple, and elm.

 
Adult Food

Adults do not feed.

 
Life Cycle

Given the long flying time for this species, there are probably two generations per year in Minnesota.

The pupa overwinters.

 
Behavior

Adults are active at night and will come to light. They rest with the wings folded tightly around the abdomen, which is raised into the air.

The caterpillar is a solitary feeder. During the day it curls up a leaf of a host plant and sticks it together with silk webbing, make a shelter where it can feed in safety. At night, it feeds in the open. Unlike all other prominents (Family Notodontidae), this species does not squirt acid as a defense.


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:

Noctuoidea (noctuid moths)

 

Family:

Notodontidae (prominents)

 

Subfamily:

Pygaerinae

 
Synonyms

Ichthyura albosigma

 
Common
Names

sigmoid prominent


 

 

 

 

 

 

 

Glossary

costal margin

The leading edge of the forewing of insects.

 

frons

The upper part of an insect’s face, roughly corresponding to the forehead.

 

seta

A usually rigid bristle- or hair-like outgrowth on butterflies and moths used to sense touch. Plural: setae.

 

spiracle

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

 

 

 

 

 

       

Visitor Photos

   
Share your photo of this insect.

Bill Reynolds


This first image it was trying to mimic a leaf and the second after I disturbed the moth from this side of the barn.

  sigmoid prominent   sigmoid prominent

       
       
       

MinnesotaSeasons.com Photos

   
       
       
       

 

Camera

     

Slideshows

   
  Sigmoid Prominent - Hodges#7895 (Clostera albosigma)
Andree Reno Sanborn
 
  Sigmoid Prominent - Hodges#7895 (Clostera albosigma)  

 

slideshow

     

Visitor Videos

   
Share your video of this insect.

     
     

Other Videos

 
  Sigmoid Prominent Moth (Notodontidae: Clostera albosigma) Dorsal View
Carl Barrentine
 
   
 
About

Uploaded on Aug 6, 2011

Photographed at Red Wing, Minnesota (04 August 2011). Go here to see the lateral profile of this specimen: http://bugguide.net/node/view/558672

 
     

 

Camcorder

         

Visitor Sightings

   
Share your sighting of this insect.

Bill Reynolds
5/16/2017

Location: Pennington Co. Minnesota

This first image it was trying to mimic a leaf and the second after I disturbed the moth from this side of the barn.

sigmoid prominent


     
     
 

MinnesotaSeasons.com Sightings

   

 


 

 

Binoculars

Last Updated:

About Us | Privacy Policy | Contact Us | © 2017 MinnesotaSeasons.com. All rights reserved.