Joro Spider Facts & Information

How Did the Joro Spider Get to the United States?

The Joro spider (Trichonephila clavata) was likely brought into the United States in 2013 or 2014 in a container ship from Japan, China, Taiwan and/or Korea, that was headed for Atlanta, GA. Since then, the Joro spider has been observed in northern Georgia and South Carolina. researchers at the University of Georgia think the Joro spider might possibly spread throughout the East Coast.

Laboratory experimentation has shown that Joro spiders may tolerate freezing temperatures quite well. A closely related species that occurs throughout the Southeast, the golden silk spider, has not expanded its range and is less cold-tolerant than the Joro spider. However, scientists who are closely following the Joro spider’s future distribution say that it is hard to predict with any certainty.

What Does a Joro Spider Look Like?

The Joro spider is classified as a part of a group of spiders known as orb weavers; aptly named for their highly organized, yellow-tinted wheel-shaped webs. Joro adult females are brightly colored with alternating yellow and black-blue color abdomens and eight legs that have yellow and black-blue segments. When fully grown, they and can measure 3-4 inches across when their legs are fully extended, or about the size of an adult’s palm. The males are considerably smaller than females and are usually brownish in color. Joro spiders build their webs well above ground, unlike many native spiders that build their nests close to or on the ground.

Where Do Joro Spiders Live?

The typical habitat of Joro spiders and their webs are along trails in the woods, in backyards and on house porches.

According to researchers with the University of Georgia, Joro spiders can relocate themselves by moving about using a “ballooning technique” in which the spiders spin a web to catch air currents that may result in traveling up to 50-100 miles away.

Joro Spider Life Cycle Facts

Joro spiders mature in early September, mate, lay eggs and then typically die by late November. One female Joro spider can lay between 400-1,500 eggs in a year. Like many orb-weaver spiders, Joro are also passive hunters, waiting for insects to get caught in their webs.

Are Joro Spiders Dangerous?

Like all spiders, Joro spiders are venomous, with a bite that somewhat compares to that of a bee sting. However, unless a person is highly allergic to Joro spider bites, they shouldn't be concerned. Joro spiders are not considered to be aggressive and will flee if their webs are harmed. A researcher collecting Joro spiders with bare hands reported an occasional pinch, but said the spider’s bite never broke the skin, so venom was never transmitted.

What Do Joro Spiders Eat?

A possible benefit of Joro spiders is they capture and feed on insects that local spiders do not eat, mainly the adult brown marmorated stink bug, which produces an unpleasant odor when threatened and also damages fruits, vegetables and crops.