Giant Lichen Orbweaver

araneus bicentenarius

The Giant Lichen Orbweaver is one of the most spectacularly camouflaged spiders in North America. Named for its striking resemblance to tree-dwelling lichens, this impressive arachnid is a master of disguise, blending seamlessly into the bark of mature trees where it spins large, vertical, wheel-shaped webs. While its formidable size can be startling to encounter, this beneficial spider is harmless to humans and plays an essential role in forest ecosystems by keeping insect populations in check. Watching one sit motionless at the center of its web, looking exactly like a piece of moss-covered bark, is an incredible testament to natural selection. They are most commonly encountered during late summer and autumn when females reach their full, impressive size.

Habitat: Typically found in mature deciduous and mixed forests, particularly on lichen-covered tree trunks, lichen-encrusted rock faces, and wooden structures.

Appearance

This large spider features a highly textured, bulbous abdomen colored in shades of grayish-green, white, and black that mimic crustose lichen. Its legs are heavily banded with dark brown and light green rings, covered in small, stiff bristles. Females are significantly larger than males, reaching body lengths up to nearly 3 centimeters, excluding their legs, while males are much smaller and less conspicuous. A distinct pair of shoulder humps on the anterior portion of the abdomen is characteristic of this species, helping distinguish it from other orbweavers.

KingdomAnimaliaPhylumArthropodaClassArachnidaOrderAraneaeFamilyAraneidaeGenusAraneus

Giant Lichen Orbweaver

Interesting facts

Despite their intimidating size, these spiders are extremely docile and rarely bite humans, with their mild venom being harmless to people.

Like many orbweavers, the Giant Lichen Orbweaver often eats its own web at the end of the night to recycle the proteins used to make the silk.

The green coloration on their body is not caused by algae or lichen growing on them, but is entirely produced by their own natural pigments.

They spin their webs primarily at night and will hide in a nearby tree crevice during the day, holding a signal line connected to the web to feel for vibrations.

Special abilities

Its coloration and physical texture perfectly match the pale-green and grey lichens of its forest home, rendering it nearly invisible to both predators and prey when resting on tree bark.

It spins large, strong, vertical orb webs up to two feet in diameter to snare large flying insects, which it quickly rebuilds almost nightly.

Utilizing specialized slit sensilla on its legs, the spider can detect minute vibrations in the silk of its web to pinpoint the exact location and size of trapped prey.

Measurements & details

Length: 1-3 cm
Weight: 0.0005-0.005 kg
Lifespan: 1 years
Clutch Size: 100-800
Incubation: 14-45 days

Diet & Feeding

Consumes a variety of flying insects caught in its sticky, vertical orb-webs, wrapping them in silk before feeding.

Age differences: Spiderlings feed on smaller insects like fruit flies and gnats, while mature adults target larger prey like cicadas and moths.

Primary Foods

Moths
Flies
Cicadas
Beetles

Foraging Method

Ambush

Ecological connections

hunts

Luna Moth

Actias luna

Prays upon large flying insects caught in its sticky orb web.

eaten by

Blue Jay

Cyanocitta cristata

Snatches spiders from their webs or bark retreats to feed to its young.

eaten by

Blue Mud Wasp

Chalybion californicum

Paralyzes orb-weaving spiders to provision its mud nests for its larvae.

Traits

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Also known as

No aliases listed yet.

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify Giant Lichen Orbweaver?

The easiest way to identify Giant Lichen Orbweaver is to use the Snappit nature identifier app.

How long is Giant Lichen Orbweaver?

1-3 cm

How much does Giant Lichen Orbweaver weigh?

0.0005-0.005 kg

How long does Giant Lichen Orbweaver live?

1 years

What does Giant Lichen Orbweaver eat?

Consumes a variety of flying insects caught in its sticky, vertical orb-webs, wrapping them in silk before feeding.

Where is Giant Lichen Orbweaver usually found?

Typically found in mature deciduous and mixed forests, particularly on lichen-covered tree trunks, lichen-encrusted rock faces, and wooden structures.

How does Giant Lichen Orbweaver hunt?

Ambush

How many eggs does Giant Lichen Orbweaver lay?

100-800