Asian Joro Spiders Spreading in US May Be Great News for Farmers

If you live in a state bordering Georgia, then you may see a new species of spider moving into your neighborhood. It will be hard to miss these spiders as they are about the size of your palm. These yellow-and-black spiders usually weave a softball-size web of gold-colored thread, but they can weave webs up to 3 feet across. While scientists call these spiders Trichonephila clavata, they are commonly called joro spiders.     Many people may never see this spider as they are timid. Unless you corner one, they will not bite you. Even if they try, they will not harm you, even though their bite contains venom. You will most likely experience a slight swelling at the bite site. They have a hard time biting humans, however, because they have very short fangs, making it difficult for them to penetrate the skin.

How Did Joro Spiders Get to the US?

It is unclear how these Southeast Asian natives got to the United States. Most experts believe that it was in some shipping container. They were first discovered in Georgia's Barrow, Jackson, and Madison counties in late October and early November 2014. From that point, their territory has significantly spread to cover more than 46,000 miles. They have been sighted as far north as Maryland and as far west as Oklahoma.

Spread by Natural Dispersal Mechanisms

Joro spiders do not have wings. Scientists believe that their territory has expanded through natural dispersal mechanisms. They are also unwilling to rule out that they may catch a ride in vehicles and spread in that way. Joro spiders do not have wings, so they cannot fly.     Young joro spiders use ballooning to reach diverse locations. They spin at least one thread designed to catch the wind, acting like a parachute. While scientists are not exactly sure how, they think that the earth's magnetic field may allow spiders to use this method to travel vast distances.