Spider Wasp

The spider in the above photo is immobile. It’s not moving. It’s not dead, but it can’t move. It’s been stung by a spider wasp and is now paralyzed. The spider is one of two different spiders I’ve found in the past two weeks on the path that winds through Catch the Wind and Explore the Wild.

Close view of paralyzed spider.

Both spiders, fairly large arachnids, were in the center of the paved path, or nearly so. In the first instance, the wasp was flying and running frantically about the spider as I approached the two of them. The wasp seemed to be looking for something, a burrow, or the trail leading to a burrow? In true spider wasp fashion it hurried about, flicking its wings and “smelling” the landscape with its bright yellow antennae.

Wasp rapidly running along ground sniffing out the scent.

These spider wasps (Entypus unifasciatus) hunt down large spiders, sting and paralyze them, then drag them off to a burrow, whether an existing burrow or a new one yet to be dug. They then lay an egg on the spider and close off the burrow to the outside world.

Soon, the egg hatches and the larva begins to consume the spider alive, though paralyzed. The wasp then pupates underground emerging the following summer to start the cycle all over again.

In leaf litter.

That’s all fascinating and somewhat gruesome at the same time, but the amazing thing about the whole process is that the wasp, after approaching and stinging the spider, single-handedly drags the unfortunate victim back to a burrow. Entypus unifasciatus is a large wasp but the spider it targets is typically larger than itself and the trail back to the burrow is usually over some pretty rough terrain.

Rough terrain can be anything from waste places or leaf litter to an unmowed, or even a mowed, lawn. For a creature the size of these wasps (about an inch in length) that’s quite a feat. I read one article that described a spider wasp dragging its prey 18 meters to a burrow, that’s almost sixty feet, in about 9 minutes time. Imagine dragging, say, an unconscious female black bear (average weight 100-300 lbs) over a bootcamp obstacle course. Tough.

Second spider (by eye configuration it appears to be a nursery web spider).

The first spider I encountered was left where found and was squashed on my next trip around the outdoor loop, the victim of a busy museum visitation day.

When coming upon the second spider I carefully picked it up and moved it to a safe location just off the path. The wasp was nowhere to be seen. Thinking the wasp was nearby searching for a burrow, or digging a new one, I reasoned it’d be back for the spider. On my next trip around the 1/2 mile loop, the spider was gone.

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