Spiders

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?️ These spiders could land here next

Photo: David Madison/Getty Images

The idea of neon green, four-inch-long spiders "flying" around cities sounds apocalyptic. But as it turns out, the Joro spider is more of a paper tiger. Why it matters: They are an invasive species spreading across the Eastern U.S., spawning alarming headlines — and making us wonder, is D.C. next? What they're saying: The exaggerated narrative is "how these giant spiders were flying into your city and they were going to eat your brains," says Andy Davis, a research scientist at the Odum School of Ecology at the University of Georgia. ?️ Reality check: First off, they don't "fly." When tiny babies, Joro spiders can throw a thread of silk into the air and catch the wind, sometimes floating for miles. That's the misconception. And once they reach adulthood, they aren't so keen on aeronautics. Plus, Joros are … shy. One of the most docile spiders ever, in fact, according to Davis. Like all spiders, they have venom. But it's unlikely you'll be bit unless you really roughly mess with one. Yes, but: Arachnophobia is still a thing; "I know these spiders are scary looking," Davis says. State of play: When will they drop in D.C.? "Every journalist I talk to wants to know the exact date of arrival, which nobody knows," Davis tells us. "Everyone seems to agree it will get there. It's just a matter of when and not if." Joro spiders are native to East Asia and have spread since first appearing in the Southeast in 2013 and 2014, particularly doing well in the urban and cooler climate of the Northeast. They could eventually invade New Jersey and New York. Right now, they are in their baby stage. They'll grow up by September and October, at which point we'll find out where they're appearing. In peak adulthood, they like to weave 3- to 4-foot large webs, near bushes and urban streets. "They seem to be able to live close to humans, unfortunately for us," Davis says. Fun facts!

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Rethinking Spider Evolution

A study published yesterday suggests spiders and their close terrestrial relatives originated from an ocean critter, challenging the assumption that their common ancestor was landbound.   Researchers used advanced imaging techniques to look inside a half-billion-year-old fossil of Mollisonia symmetrica, an extinct aquatic creature long believed to be the ancestor of horseshoe crabs. The fossilized brain and central nervous system patterns they saw more closely resembled those of modern spiders, scorpions, ticks, and other arachnids than today’s horseshoe crabs.   Arachnid and Mollisonia brains are backward compared to other invertebrates, like insects and crustaceans. The regions responsible for dexterous actions are in the back, closer to the neurons that drive leg movements. This formation fosters neural shortcuts that enable swift speed vital to spinning webs and hunting prey.    According to the study's lead author, insects may have developed wings to evade nimble and hungry Mollisonia-like arachnids migrating onto land. In their own evolutionary response, spiders began creating sticky webs.