The East Gippsland town of Traralgon was one of the hardest-hit areas by recent flooding and wild weather. While its neighbour Sale avoided the brunt of the damage, flooded roads and paddocks disrupted the local spider populations, which are now seeking higher ground on road signs, trees and any tall grass they can find.
“It’s just incredible, when they blow in the winds they look like waves,” said Jena Beatson, who saw the spiders on her first trip into Sale from Longford after the roads were cut off by flood waters.
“It does look creepy the way it covers all the signs and everything. You can’t really see it in the photos but there are spiders all over. It’s like thousands and thousands of spiders.”
Actually, according to Dr Ken Walker, a senior curator of entomology at the Melbourne Museum, it is millions.
“It’s a semi-regular occurrence in Victoria in wintertime when we get most of our rain. Spiders can make a wide range of different silks and one of the silks they use for this behaviour – ballooning – it’s a very, very thin little silk that they use … to fly away with the breeze. They could fly 100km,” he said.
“What’s happened is there’s been a massive flooding event pretty quickly … so they’re using the ballooning not to escape for hundreds of kilometres but to almost throw up a lasso on top of the vegetation. It hooks on to the tops of the vegetation because it’s lighter than air, and then they quickly climb up.”
When a huge number of spiders all do this at once, they end up hooking on to each other and can blanket the countryside.
This phenomenon, sometimes called the gossamer effect, is caused by “vagrant hunter” spider species, which live on the ground and do not build a web. They also do not create webs after ballooning away from a flood. In fact, Walker said, each spider only threw up a single thread, meaning every tiny line of silk represented a different animal.
