Joro Spider (Trichonephila clavata) — identification, habitat & look-alikes

Joro spiders are now in several southeastern U.S. states, where their large golden webs become conspicuous from late summer into fall. An adult female can span about 4 in (10 cm) across the legs and has bright yellow and blue-gray bands plus a red mark underneath. Joro spiders rarely bite people, and reported bites usually cause only short-lived pain and redness.

Appearance

Appearance: Adult females reach about 1 in (2.5 cm) in body length and up to 4 in (10 cm) across the legs. Males are only about 0.3 in (0.75 cm) long and are mostly brown.

Look-alikes

golden silk orb-weaverTrichonephila clavipes

The golden silk orb-weaver has a yellow-orange abdomen with two rows of pale spots and brush-like black hair tufts near several leg joints. A female Joro spider has broad blue-gray bands on a yellow abdomen, black legs with yellow bands, and a bold red mark underneath.

Why they get mixed upBoth are large golden-web builders in the southeastern United States.

banded garden spiderArgiope trifasciata

Its abdomen has many thin black, yellow, and silvery bands. A female Joro spider has broader blue-gray bands on yellow and a red mark underneath.

Why they get mixed upBoth are large, banded web-building spiders in the southeastern United States.

Three large banded spiders in the Southeast

	Abdomen	Useful close-up clue
Joro spider	Broad blue-gray bands on yellow	Large red mark underneath
golden silk orb-weaver	Rows of pale spots	Black hair tufts at leg joints
banded garden spider	Many thin black, yellow, and silvery bands	No broad blue-gray bands

Where it lives

Typical habitats: woodland edges
yards
parks
roadsides
Range: Native to East Asia, it was first detected in Georgia in 2014. It is established in Georgia, Alabama, North Carolina, South Carolina, and Tennessee; isolated populations have also been found in Maryland, Virginia, and Pennsylvania. Its introduced U.S. range is expanding.
Preferred conditions: Females suspend very large webs between trees, shrubs, fences, utility poles, and buildings.
When it’s recorded: Recorded May–Dec most years · most records in Sep–Oct
Active Aug–Dec
8,990 observations in the US · 9 years · for referenceChoose a state

Behavior

Diet: They catch flying and climbing insects in their webs.
Activity: Mature females are most noticeable from late August through fall and have been photographed into early December in Georgia.

Life cycle

Breeding season: In Georgia, females lay s from mid-October through November.
Nest: A female attaches a dense, white silk egg sac to leaves, bark, or a human-made surface.
Clutch size: An egg sac holds hundreds of eggs. The eggs overwinter, and young spiders can disperse by .

Cautions

Cautions: They rarely bite, their small fangs have difficulty piercing human skin, and reported bites usually cause only short-lived local pain and redness.

Name and classification

About the name: Older sources called it Nephila clavata. Trichonephila clavata caerulescens is a .

Conservation

IUCN Red List: LCLeast ConcernLow risk of extinction

Culture and stories

Culture and stories: The English name Joro spider comes from the Japanese name jorō-gumo.

14 sources