Juvenile Yellow Garden Spiders

Adult female yellow garden spider.
Photo courtesy of Spencer Bawden.

The spider Argiope aurantia is known commonly as the yellow garden spider. It is common in Central America, Mexico, Hawaii, the contiguous United States, and southern Canada. Their range of habitat is rather diverse, including grasslands, woodlands, and from near bodies of water to dry grassy hillsides.  

Yellow garden spiders breed once a year. To attract a female the male spider will build a small web near or actually in the female’s web. The male will then pluck strands on the female’s web to court her. Males often have a safety drop line ready in case the female attacks him. The male dies after mating and is often eaten by the female.

At night the female will lay her eggs on a sheet of silky material, cover the eggs in another layer of silk, and cover them in yet another layer of protective silk that is brownish in color. She will then turn the sheet into a ball and suspend the egg sac from her web.

 On May 10, 2015 I noticed a cluster of baby spiders grouped together on the lid of a jar. I was surprised to see them there because they were quite out in the open. They were fully exposed to the elements yet they weren’t inclined to seek shelter where they would have been out of sight to predators. I was also surprised to see these spiders congregating in one area because I had been under the impression that when spiders hatch they almost immediately fly away on strands of silk that get caught by the breeze.

I initially was not planning on observing these spiders, but fast forward five days from when I first observed them and they were still grouped together in the same spot. I thought this to be rather unusual. There was no food source for the spiders that I could see and no web for them to catch food in.

In the hour that I studied these spiders I came to learn that juvenile yellow garden spiders are generally inactive. They would group together in a compressed ball, all stacked on top of one another. The spiders at the base of the ball would lie on their backs, which I believe was done to make a more closely knit congregation.

       

I gently blew on the group of spiders a few times to see how they would react. Upon doing so the spiders would rapidly dissipate and scatter in every direction. It was odd because the spiders never strayed off the lid. They would run for a few centimeters and then come back to congregate in a ball. After an hour of observing the spiders I came back periodically throughout the day to check on them. Each time they were in their little ball, unmoving. I left the spiders unobserved for two days. When I came back to check on them they had left the nest.