I said I was going to tend to my shiny newborn Steatoda triangulosa today. It didn’t take as long as I expected. Here’s the vial of my freshly emerged spiderlings; the egg sac is the foamy looking bubble at the bottom, attached to the yellow plug on the vial, and the little dots are the babies.
There were only nine spiderlings from that egg sac. It was a bit of a surprise, since when a Parasteatoda egg sac pops, I easily get over a hundred spiderlings. It makes me wonder how well S. triangulosa does in the wild — I can tell you from our summer survey that they were the rarest of the false widows we found, with even S. borealis far more numerous, and they were a distant second to Parasteatoda. Now I’m curious about what niche they fill in the local spider ecosystem.