Marbled Orbweaver

Araneus marmoreus

Classification

Pronunciation

How to pronounce Araneus marmoreus: /ˈa.ra.ne.us marˈmɔː.re.us/

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Images

Summary

Araneus marmoreus, commonly called the marbled orbweaver or pumpkin spider, is a species of spider in the family Araneidae known for its distinctive color patterns and large, spherical abdomen resembling a pumpkin. It has a Holarctic distribution and plays a significant role in controlling insect populations in its habitat.

Physical Characteristics

Female: 9-18 mm; Male: 6-9 mm. Two main color forms are present: var. marmoreus (orange abdomen with brown to black marbling) and var. pyramidatus (paler abdomen with a single dark mark). Cephalothorax is commonly yellow to burnt-orange with a central dark line.

Identification Tips

Look for the large oval, sub-spherical abdomen of the female, which resembles a pumpkin. Color patterns can vary widely, often with a folium pattern present.

Habitat

Moist, wooded settings; commonly found in trees, shrubs, tall weeds, and grasses.

Distribution

Holarctic distribution: North America (Canada to Alaska, northern Rockies, North Dakota to Texas, east to the Atlantic) and Europe to Japan.

Diet

Carnivorous, primarily feeding on insects trapped in its web.

Life Cycle

Eggs are deposited in October inside white silk cocoons, with immature spiders emerging in spring. Adults are seen from midsummer until the first hard freeze of fall.

Reproduction

Egg cocoons contain several hundred eggs; females lay eggs in the fall and young emerge in the spring.

Ecosystem Role

Predator of various insects, playing a role in controlling insect populations.

Cultural Significance

Commonly referred to as marbled orbweaver or pumpkin spider due to its distinctive appearance.

Collecting Methods

  • Hand collection
  • Use of sweep nets

Preservation Methods

  • Killing jar with ethyl acetate
  • Pinning
  • Alcohol preservation

Similar Taxa

Misconceptions

Often confused with other orb-weaving spiders; may be mistaken for a dangerous species due to its size, but it is non-venomous to humans.

Tags

  • Araneidae
  • orbweaver
  • spider
  • Holarctic
  • insects