Alert reader John sent me this recent notice from the Chicago Hilton, located downtown.
Now there are two minor errors here, most notably the misspelling of the species, which is really Larinioides sclopetarius. Note, too, that the second name in the Latin binomial is never capitalized though the first one is; this is a common error, almost as common as capitalizing neither name, as in “homo sapiens”, or not using italics). And if there are arachnologists reading, they may see further flubs.
But that’s picking nits. What impresses me is that the biology is basically correct, and they impart so much of it to the wary guests (“spinnerets,” “orb weaving”, the ecology, and so on). Kudos to the Chicago Hilton for giving guests a biology lesson, even though it’s clearly designed to allay their fears about Flying Spiders.
A 1999 New York Times article about building a high-rise apartment in Chicago noted the following:
There may be one other barrier between residents and their views: the orb-shaped web of Larinioides sclopetarius, the high-rise spider. [JAC: ITALICS, plz!]
”It’s a species that’s attracted to rocks overhanging water,” said Dr. Petra Sierwald, a curator at the Field Museum here. ”These high-rise buildings are just very big rocks overhanging water.”
High-rise spiders can climb or balloon to the top on strands of silk blossoming from their spinnerets. They are clever enough to hide before the window washers arrive and plucky enough to spin a new web after the crew moves on.
”These critters eat like kings,” Dr. Sierwald said. ”It’s prime real estate for spiders.”
Here, by the way, is a specimen of the High Rise Flying Spider:
Wikipedia has a nice article on spider ballooning. Read and learn (do it!):
A spider or spiderling after hatching will climb as high as it can. The spider then stands on raised legs with its abdomen pointed upwards. This is known as “tiptoeing”. After that, it starts releasing several silk threads from its abdomen into the air, which automatically form a triangular shaped parachute. The spider can then let itself be carried away by updrafts of winds, where even the slightest of breeze will do. Most rides will end a few metres later, or a spider can be taken up into a jet stream, which depends on its mass, posture, the convectionair current, drag of silk and parachute to float and travel high up into the upper atmosphere.
Many sailors have reported spiders being caught in their ship’s sails, over 1600 km from land (Heimer 1988). They have even been detected in atmospheric data balloons collecting air samples at slightly less than 5 km (16000 ft) above sea level.Apparently it is the most common way for spiders to invade isolated islands and mountaintops. Spiderlings are known to survive without food travelling in air currents of jet streams for 25 days or longer.
Here’s a really lovely video of a baby spider ballooning. Watch it to the end; it comes into focus, the silk comes out, and poof!—the spider’s off on a journey to the unknown.