Eggsack of Black and Yellow Spider

Description:

The black and yellow garden spider makes this purse like egg sack. A jumping spider was visiting this one. After mating, each female produces one or more (usually no more than three) brown, papery egg sacs. They are round in shape and up to an inch wide—each containing 300 to 1,400 eggs. The female attaches her egg sacs to one side of her web, close to her resting position at the center, since suspending the cocoon is particularly effective against ant predation. The multi-layered wall of the cocoon provides barriers against burrowing larvae of insect predators, though some wasps and flies lay their eggs in A. aurantia egg cases. One study found that in addition to A. aurantia, 19 species of insects and 11 species of spiders emerged from A. aurantia egg cases. The vast majority, however, are eventually damaged by birds.

Habitat:

Riparian meadow.