Marbled Orb-Weaver, Pumpkin Spider
Araneus marmoreus
Family Araneidae (Orb-Weavers), Order Araneae
Physical Description
The Marbled Orb-Weaver exhibits strong sexual dimorphism. Females possess a large, bulbous, highly rounded or oval abdomen that appears heavy and swollen, especially when gravid. The cephalothorax is smaller, compact, and typically reddish-orange or brown. The surface is smooth with fine hairs.
Size Estimate
Females range from 9 to 20 mm in body length, while males are smaller, ranging from 6 to 9 mm. The overall leg span can reach up to 40 to 50 mm.
Coloration & Markings
This species is famous for its vibrant coloration, particularly the highly variable abdomen which ranges from bright yellow and orange to dark brown, heavily decorated with dark marbling, spots, or a distinct central leaf-like pattern. The legs are reddish-orange with distinct black and white or yellowish banding.
Web Type
Constructs large, vertical orb webs typically built among low vegetation, shrubs, or the eaves of buildings. A retreat made of rolled-up leaves or silk is usually built near the edge of the web.
Eye Arrangement
Eight small eyes arranged in two distinct rows on the anterior portion of the cephalothorax, typical of the orb-weaver family Araneidae.
Leg Characteristics
Long, robust legs featuring prominent spines and distinct dark and light banding patterns. The legs are held widely spread to detect vibrations across the orb web.
Venom & Safety Information
Venom Information
Neurotoxic/cytotoxic venom used strictly to immobilize insect prey. It is low in potency relative to humans and entirely non-lethal.
Medical Significance
Not medically significant. Bites are extremely rare, usually occurring only if the spider is directly squeezed or trapped against human skin. Symptoms are mild, typically limited to minor localized pain or redness similar to a bee sting.
Safety Recommendations
No special precautions needed. If found indoors, gently guide the spider into a container using a piece of paper and release it outdoors.
Habitat & Behavior
Habitat & Range
Found throughout North America and the Palaearctic region. Preferred habitats include woodlands, gardens, fields, and around human structures where vegetation provides anchor points for webs.
Behavior & Temperament
Docile and non-aggressive. They spend daylight hours hiding in their silk-and-leaf retreats, waiting for the night or dusk to sit at the hub of the web and hunt.
Diet & Prey
Generalist predators feeding primarily on flying insects such as flies, moths, mosquitoes, and beetles trapped in their vertical orb webs.
Seasonal Activity
Most active during late summer and autumn when adults reach full size and females prepare their egg sacs.
Description
The Marbled Orb-Weaver is one of the most visually striking and colorful spiders in its range. Best known for its pumpkin-like, brightly patterned abdomen, this spider is a master architect, spinning intricate vertical wheel-shaped webs to capture passing prey. They are a wonderful addition to any garden, serving as natural pest control while displaying fascinating nocturnal habits.
Key Features
Bulbous, highly rounded abdomen featuring bright yellow or orange background tones with dark marbling or a central pattern; reddish-orange cephalothorax and banded legs.
Similar Species
Araneus diadematus (European Garden Spider), which features a prominent white cross on the dorsal abdomen rather than marbling.
Life Cycle
Females lay eggs in late autumn, encasing them in a spherical silk egg sac hidden in bark or leaf litter. Spiderlings hatch in spring, mature through successive molts over the summer, and complete their annual life cycle by winter.
Ecological Importance
Acts as an effective biological control agent by consuming large quantities of flying agricultural and garden insect pests.
Conservation Status
Not evaluated by the IUCN, but populations are secure, widespread, and common throughout their native range.
Interesting Facts
Often called the 'Pumpkin Spider' due to its appearance, which peaks in abundance right around Halloween. Some individuals can have almost entirely solid dark brown or black abdomens.
Photography Tips
Photograph from the side or slightly above to capture the intricate abdominal patterns and leg banding. Use macro lenses with a fast shutter speed, and photograph at dusk when they emerge onto the web hub.
Identified: 2026-09-10T22:34:49.240689