We Must Protect This House
It’s like a maypole erected within a barbed wire fence! Not only does the central pole have several “guy-wire” support strands keeping it up, but the outer poles have horizontal strands strung between them, just like our fences. It’s almost certainly a defense mechanism against ants or other predators for whatever is incubating inside. What an amazing evolutionary feat!
Several commenters at Why Evolution Is True believe it is either the egg sac of a mystery spider or a very elaborate moth cocoon. While some moths have been known to erect Stonehenge-like fences around their cocoons, I lean more toward the spider theory.
Moth cocoons (like this incredible lace-like cage observed by Destin from Smarter Every Day) are spun by the caterpillar that is cooking inside, and I just can’t see a way that this silk was spun by the resident. It’s just too elaborate. More likely that a spider built her babies this safe little home and then sailed away. Ideas?
Other theories: Tiny Area 51, Insect Isengard, air traffic control station for jungle birds.
Ahh, I could kiss you, evolution.