A spider in Southern California is building a house the size of your palm and flying through the air, riding the wind.
Although the Zorro spider, an invasive species that has been spotted throughout the United States, including California, is not dangerous, its size and the web it creates may seem like props from a horror movie.
“They are not medically significant,” said Pat Wooden, insect identification laboratory manager at Virginia Tech. “They’re very big insects, but they won’t bite you and won’t do terrible damage. They’re really well established, so there’s not much we can do against them. Their spider webs can be up to 10 feet high.”
The spider has recently been found in California, Wooden said, with the first report coming in October. They have no natural predators and have a large web capable of catching a variety of prey including beetles, wasps and stink bugs. Spiders are also good at keeping themselves away from each other so they don’t compete.
Wooden advises that people try not to panic and do nothing if they see something like this. Spiders benefit humans by acting as natural pest control, eating mosquitoes, biting flies, and invasive stink bugs. Their venom is not dangerous to people or pets and they rarely bite.
Spiders propagate themselves by “ballooning”, in which the spiders release silk that stretches into the air, allowing them to travel. This gives people the false impression that spiders can somehow fly.
“They are incredibly prevalent and people interact with them a lot,” she said. “We’ve gone from people who thought they flew, to the real scary thing that came with them.”
Wooden said the spider was first spotted in the U.S. in 2014 in Georgia, likely brought into the country via shipping containers from China, Taiwan, Japan and South Korea.
The spiders are particularly prevalent in Appalachia and have also been observed in South Carolina, North Carolina, Tennessee, Kentucky, West Virginia, Virginia, Maryland, Pennsylvania, Mississippi, Alabama, Ohio, and Florida.
“We realized we’re just going to be stuck with them,” Wooden said. “They’re becoming more prevalent and they’re slowly making their way into the Southeast. When we worked in Tennessee recently, there was a reef in every single reef.”
The University of Georgia College of Agricultural and Environmental Sciences and the Warnell School of Forestry and Natural Resources found the spider so interesting that they launched a website, Jorowatch.orgTo track where spiders have emerged across the country. Most have been reported in Georgia. The website shows some of the spiders reported in Santa Barbara County as recently as October.
According to the website, the spiders are active from September to October and are circular weavers known for weaving spiral circle-shaped webs. They can be identified by their yellow abdomen with red markings and the golden color of their webs.
Male Zorro spiders are approximately 0.25 inches in size and are mostly brown in color while female spiders are approximately 1.25 inches in size and are mostly yellow in color.
According to Jarrowwatch, the spiders’ white egg sacs, usually laid between October and November, are often attached to leaves, tree bark and flat structures and contain 400 to 500 eggs.
