Joro Spider

What it does

Joro spiders are orb-weavers that hang in the center of large, strong, golden-tinted webs, often in clusters. They are timid and slow to bite, usually fleeing or dropping when disturbed. Their webs can span walkways, porches, and garden gaps, which is the main way they bother people. Young spiders balloon on silk to disperse on the wind.

Where it lives

Native to Japan, Korea, and China, the Joro spider arrived in Georgia around 2013 and has spread across the Southeast. It builds webs outdoors in gardens, tree lines, power lines, porches, and between structures, often near homes. It tolerates cold better than many relatives, which may aid its northward spread.

How it breeds

There is one generation a year. In fall, females produce an egg sac holding hundreds of eggs, then die at the first frost. The eggs overwinter, and tiny spiderlings emerge in spring, dispersing by ballooning on silk threads. They grow through the summer, reaching full, showy size by late summer and early fall.

What it eats

Joro spiders eat flying and crawling insects caught in their webs, including mosquitoes, flies, stink bugs, and even the invasive spotted lanternfly. As generalist predators they can be a modest benefit in the garden, helping reduce nuisance and pest insects.

Identification

Females are large and unmistakable: a body around an inch long with bright yellow and blue-gray bands, red markings underneath, and long banded legs spanning three to four inches. Males are much smaller and drab brown. The web is a large, three-dimensional, golden-silk orb, often with tangles of support lines.

Signs of an infestation

• Large golden orb webs across paths, eaves, and gardens
• Big yellow-and-gray spiders sitting head-down in webs
• Clusters of webs in tree lines and along fences
• Small brown males near a female in her web
• Silk egg sacs on bark or structures in fall

Prevention tips

• Clear webs with a broom from doorways and walkways you use
• Trim vegetation and reduce clutter near the house to limit web sites
• Turn off unneeded outdoor lights that draw prey insects
• Relocate spiders outdoors rather than killing beneficial ones
• Knock down and destroy egg sacs in fall to limit next year's numbers

Professional solutions

Joro spiders almost never need professional pest control. They are harmless and even helpful, so the usual advice is to leave them be or relocate them. If webs are truly overwhelming a porch or entry, routine web removal and reduced outdoor lighting solve it. General pest control that lowers their insect prey will indirectly reduce spider numbers.