Throughout the state of Iowa, blankets made of spider webs are seen, on which people post photos of trees and lawns thickly draped with silk strings.
It’s been called “Spiderpocalypse”, but as strange – or terrible, depending on one’s attitude to spiders – as it may seem, it’s not an unusual phenomenon caused by unseasonably warm weather.
Many spiders die or rest in winter and prepare for the colder months by mating and laying their eggs in late summer and early autumn so that they can hatch in spring.
However, the weather in Iowa has been erratic lately, with snow and freezing temperatures in October, followed by a sharp increase this month. Temperatures were consistently above 70 degrees Fahrenheit in the first week of November, but have since fallen again.
These fluctuations have resulted in millions of spider eggs hatching months earlier than they were supposed to hatch.
What the? Webs cover the trees and grass in WDM! Does anyone know what’s going on? ð¤ @KCCINews pic.twitter.com/pEKOhVA79U
– Tommie Clark (@TommieClarkKCCI) November 5, 2020
Who can tell me what’s going on today with these spiders hatching in Iowa? pic.twitter.com/jyBGr4Z7Ld
– MrsKultScience (@MrsKult) November 5, 2020
Do you have any information about what was the cause of the cobwebs covering the previous day? Curious in the area of Des Moines. pic.twitter.com/ZB5LRNJhN2
– Rachel (@RachelPBunko) November 6, 2020
Each spider egg sac can contain hundreds of eggs. When the baby spiders hatch, they crawl out of these nests and spin silk threads to catch the wind and transport them to another place, a phenomenon known as “ballooning”.
However, the winds in Iowa were not strong enough to carry the spider babies away, so they got stranded. Millions of balloon strings can now be seen on grass and trees throughout the state.
“These spiders are not dangerous, and this outdoor spider phenomenon will not affect your health or well-being,” Donald Lewis, professor of entomology at Iowa State University, told the Des Moines Register.
“Enjoy the show before the cold.”
Lewis also wrote about the phenomenon in 2009, reporting: “The good news is that the spider’s web is not a problem, the phenomenon is short-lived and the situation will pass without any treatment or attention being required, except that you can admire the site while you have the opportunity.
Adam Thoms, an assistant professor in the Department of Horticulture, wrote in an Iowa State University blog post that “almost all” of the spider children “would die of dehydration or starvation because there is not enough food for so many spiders to survive this time of year.
He added, “Because of the season and the relatively dry weather conditions [grass strands], the baby spiders are neither mowed nor disturbed, so the baby spiders make all those spider webs that you see and don’t feel disturbed by anything.