starbellied orbweaver

(Acanthepeira stellata)

Conservation Status
starbellied orbweaver
Photo by Babette Kis
  IUCN Red List

not listed

     
  NatureServe

NNR - Unranked

     
  Minnesota

not listed

     
           
           
           
           
           
           
           
 
Description
 
 

There are four species of starbellied orb-web spiders (genus Acanthepeira), all of them occurring in southeastern United States. Starbellied orbweaver (Acanthepeira stellata) is the only one whose range extends into northern United States and southern Canada.

Starbellied orbweaver is a common but not abundant, medium-sized spider. It occurs in the United States and southern Canada east of the Great Plains, in Mexico, and there is a disjunct population in southern Arizona. It is found in summer and fall in open sunny areas, including fields, meadows, woodland edges, and agricultural crops, and sometimes on buildings. It is most easily found in the early morning when its web is covered with dew.

Females are ¼ to (7 to 15 mm) in length and have a to (9 to 15 mm) legspan. The overall color can be brown, brownish-orange, or grayish-brown. The following description is of the brown color phase.

The front part of the body (cephalothorax) is low, narrowed in front, and much smaller than the abdomen. The upper side (carapace) is dark brown with narrow pale margins and is covered with whitish hairs. There is no depression in the middle.The head region is highest, appearing swollen.

There are eight eyes arranged in two parallel rows of four eyes each. The front (anterior) row is strongly curved forward and the rear (posterior) row is strongly curved backward. All of the eyes are small, but in the anterior row the middle (median) eyes (AME) are the smallest. The corners of the head are extended forward over the anterior outer (lateral) eyes (ALE).

The abdomen is large, oval, rounded, and highest in front. The outer edge has twelve prominent, cone-shaped, outward pointed humps (tubercles); one in front projecting over the carapace, one at the rear projecting over the spinnerets, and four on each side. The first tubercle on each side is doubled, two closely spaced tubercles joined at the base. The upper side of the abdomen is brown with light and dark markings. At the front margin there is a white Y-shaped or V-shaped mark bordering a dark interior. Toward the rear there is a dark leaf-shaped mark (folium). The common name of the spider may refer to the shape of the folium or to the star-like shape of the abdomen.

The legs are short, spiny, and yellowish, with distinct brown rings. The front two pairs project forward, the hind two pairs project backward. The last segment (tarsus) on each leg has three claws at the tip, though these are not visible to the naked eye.

The male is much smaller, 316 to 516 (5 to 8 mm) in length. The carapace has a shallow, indistinct depression. The finger-like sensory appendages attached to the mouth (palps) are enlarged.

 
     
 

Size

 
 

Female Body Length: ¼ to (7 to 15 mm)

Male Body Length: 316 to 516 (5 to 8 mm)

Legspan: to (9 to 15 mm)

 
     
 

Web

 
 

The female constructs a large oval web. It is called an “orb”, which gives this family of spiders its common name. The web is 6 to 10 (15 to 25 cm) in diameter and has about 25 radii. It hangs vertically, within four feet of the ground, in the upper half of vegetation, usually tall grasses or low shrubs. The center of the hub is closed or nearly closed. A retreat is constructed in the dead head of one of the plants that supports the web. At night, the female hangs head down in the center of the web. During the day she may be found there, but she is usually found in the retreat.

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Fields, meadows, woodland edges, agricultural crops, and buildings

 
     
 
Biology
 
 

Season

 
 

Summer through fall

 
     
 

Behavior

 
 

Adults are active at night but can often be found in the center of their web in the early morning.

When disturbed, the spider drops to the ground, tucks in its legs, and feigns death. Its coloration provides excellent camouflage among the leaf litter and tangled grasses.

 
     
 

Life Cycle

 
 

Eggs are attached to nearby leaves. Eggs overwinter, and spiderlings hatch in the spring.

Spiderlings disperse by “ballooning”. They climb a branch, blade of grass, or fencepost, and release a long thread of silk. The silk thread catches the wind or even a light breeze and the spiderling floats to a new site.

The male matures earlier than the female. Adults are active from summer to the first frost or hard freeze.

 
     
 

Food

 
 

Flying insects

 
     
 
Distribution
 
 

Distribution Map

 

Sources

24, 27, 29, 30, 82, 83.

 
  3/10/2023      
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
  Class Arachnida (arachnids)  
 

Order

Araneae (spiders)  
 

Suborder

Araneomorphae (typical spiders)  
  Infraorder Entelegynae (entelegyne spiders)  
  Superfamily Araneoidea (araneoid spiders)  
 

Family

Araneidae (orbweavers)  
 

Subfamily

Araneinae (typical orbweavers)  
 

Genus

Acanthepeira (starbellied orb-web spiders)  
       
 

Synonyms

 
 

Acanthepeira venusta

Araneus stellata

Cyrtarachne dugesi

Cyrtarachne mexicana

Epeira nobilis

Epeira stellata

Marxia nobilis

Marxia stellata

 
       
 

Common Names

 
 

starbellied orbweaver

star-bellied orb weaver

star-bellied orbweaver

 

 

 

 

 

 

 

 

 

Glossary

Carapace

The hard, upper (dorsal), shell-like covering (exoskeleton) of the body or at least the thorax of many arthropods and of turtles and tortoises. On crustaceans, it covers the cephalothorax. On spiders, the top of the cephalothorax made from a series of fused sclerites.

 

Cephalothorax

The front part of the body of various arthropods, composed of the head region and the thoracic area fused together. Eyes, legs, and antennae are attached to this part.

 

Folium

On some spiders, the leaf-shaped marking on the upper side of the abdomen.

 

Palp

Short for pedipalp. A segmented, finger-like process of an arthropod; one is attached to each maxilla and two are attached to the labium. They function as sense organs in spiders and insects, and as weapons in scorpions. Plural: palpi or palps.

 

Tubercle

On plants and animals: a small, rounded, raised projection on the surface. On insects and spiders: a low, small, usually rounded, knob-like projection. On slugs: raised areas of skin between grooves covering the body.

 

 

 

 

 
 
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Babette Kis

 
 

Starbellied orbweaver

 
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Other Videos
 
  2020 10 27 Acanthepeira stellata Star bellied Orb-weaver
Hari Krishna
 
   
 
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Oct 28, 2020

 

 

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  Babette Kis
9/21/2020

Location: Barnes Prairie Remnant, Racine Co., WI

 

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Created: 3/2/2023

Last Updated:

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