Bolas Spider Egg-Sacs
Frank showed me these weird, but very cool pods this morning.
They obviously were made by a spider as they were suspended from the avocado tree by webs, but they looked more like gum nuts to me than anything a spider would make. I’ve seen a lot of spider cocoons in my day but all of them were obviously made of silk and looked like they came out of the back of a spider. These absolutely did not look like a spider had spun them.
So onto the internet I went and, lo and behold, these are Bolas Spider Egg-Sacs (spun by a spider – shows how much I know). Apparently I can expect a few hundred little spider babies to come ballooning down in late winter. If only they ate aphids rather than moths, they would be my new best friend. Wait, perhaps they eat cabbage moths! If so, I’m starting a breeding program.
What’s unique about these spiders (beyond their fantastic egg sac) is the way they hunt. They actually make a string of silk with a blob of gooey silk on the end and with a really alluring smell smeared all over it (a pheromone irresistable to moths). When a moth gets close enough to check out its potential mate, the spider swings the string, much like an Argentinian cowboy swings his bolas, and snares the moth.
This spider is actually either an Ordgarius magnificus (Magnificent Bolas), or an O. furcatus or O. monstrosus. Since I haven’t seen the actual spider, I’m not going to try to narrow it down.
Laura Rittenhouse's Gardening Journal 