Purseweb Spider

Purseweb Spider’s web

A few years ago, Laurie and I were hiking in the Enchanted Forest Nature Sanctuary. With a name like that, how could we resist? This was near Titusville, Florida.

On the way back to the car, we noticed a green tube running up the base of a moss-covered tree trunk.

Oh, how cool. This was a Purseweb Spider’s web.

I had seen a drawing of a tube like this when I was a little kid. It was in a Golden Guide Book named Spiders and Their Kin. I had wanted to see one of these ever since then, but had never expected to do so. They seemed so exotic and improbable.

The spider lives in a hole at the base of the tree trunk and spins its tubular web upwards along the tree trunk. When prey disturb the web by crawling on the outside of the tube, the spider runs up the inside of the tube. The spider bites through the web, and pulls the prey into the tube. That might be why the top of this tube, the white part, is disturbed…maybe the spider had captured some prey recently.

Some of the accounts I’ve read say that the spider decorates the outside of the tube with moss and lichen to make the tube blend in with the tree trunk. I’m not sure what the mechanics of that would be, exactly how the spider does it. Does it just go out and scrape moss off of the surrounding tree, and carry the moss back to the web? How much work that would be for a spider.

Moss and lichen grows over the tube as well, camouflaging it. I’d expect that eventually this overgrowth would render the tube useless for catching prey. Does the spider clean it off, or just build a new one?

This was a pretty neat thing to see.