Scientists have discovered a new species of spider spinning that lives only in a cave in southern Indiana. As the name implies, this spider spins flat, densely woven, horizontal webs. There are thousands of types of cloth weavers, and you've probably gone by one of their nets by accident.
"In the morning, when dew is on the grass, and you see the little horizontal nets, these are arcades," said Marc Milne to Gizmodo. Milne is an arachnologist at the University of Indianapolis who identified the new spider in Indiana
This new bow weaver, called Islandiana lewisi is most likely not dangerous to humans. It is only about 2 millimeters long and probably eats other small arthropods like springtails.
"Spring tails are like little salad bags for spiders, they are soft and full of nutrients," Milne said. "If the springtails jump in the air, they can land and get stuck in these tracks." Although he has not directly observed it, Milne thinks that this happens in the Stygeon River Cave where I. lewisi live.
As described in his June 1945 study Subterranean Biology Milne called the new Spider lewisi as a nod to his colleague Julian Lewis, an Independent Isopod taxonomist who first published his Paying attention to the spiders hiding in the Indiana Cave
Milne went to see the spiders for himself and found the cave a bit treacherous to navigate. "It's actually a bit tight," he told Gizmodo. "It's small and tight, you have to scramble to get in."
He added that the cave occasionally spills over, making it very wet and dirty. But the spiders seemed to be right at home turning their lanes between huge, mud-covered boulders. While the spiders had lost some of their pigment and were slightly translucent (a common feature in low-light, caving creatures), he noticed that their eyes had not shrunk. This made him believe that the spiders had not occupied the cave as long as many of the other cave animals we know – maybe just a few million years as opposed to hundreds of millions of years.
Thought it seems strange a new spider lurking in Indiana undetected, Milne says it's a misconception that all new spiders are found in sparsely populated areas.
"When people think of new spiders, they think of the Amazon or the ice under the Antarctic," he said. "But even in our backyard, there are many new, undiscovered organisms that we do not know very much about, people think we know all about the organisms in the Midwest and the United States because we've been through the land, but in reality we do not … many groups are really little explored spiders are just one of them. "