Thursday, October 27, 2016

"The Bug That Stalks Spiders on Their Own Webs"

Atlantic:

More surprisingly, the bugs can also break the web strands with impunity. If a thread stands between them and their spider prey, they’ll simply grab it with their front legs and pull it apart. It’s a risky move. The threads of a web are held in tension, like taut rubber bands. If you cut them, the two ends ought to spring back, creating vibrations that would give away an interloper’s presence. And yet, astonishingly, the spiders don’t notice. The bug can even break threads that are right next to a spider without drawing attention to itself.

Soley noticed that when a bug snaps the threads, it holds on to the disconnected ends and lets them to sag toward their points of origin before releasing them. It does so one at a time, and often separated by long delays. All of this allows the bug to vandalize the web without creating vibrations, or at least, none that are distinguishable from background noise and wind. In fact, Soley also found that the bugs are more likely to break threads in breezy conditions. It’s an assassin that camouflages itself with wind.