Grass Spiders

I walk out of my office on a chilly December day. I pull my coat up around my neck to block the wind, and make my way out to the grassy hill with a view. The hill, where I took pictures of wildflowers in lush green in April, and watched buckeye butterflies in the crispy dry grass in August, is just starting to turn green again. It's dotted with patches of glittering white. The white patches are spider webs, covered in dew.

Bending close I see that each one has a funnel, or two or three. The funnels curve toward the ground. I can't see how far down they go.

A little research reveals that these webs are made by grass spiders. There are several local species, all in the genus Agelenopsis. Grass spiders are slender, brown and beige spiders. Their webs are not sticky, but the spiders move very quickly and rush out from the funnel to catch prey when vibrations on the webs cue the spiders to emerge. They are mostly nocturnal, end even then, spend most of their time tucked in their funnels, so they are rarely seen.

The grass spiders' webs are there on the hillside all year long, but I didn't notice them until now. The cool temperatures and moist air of December bring the dew, which outline the webs in glittering beads of water. It's an interesting twist on seasonal nature: the organism isn't doing anything differently this time of year, but changes to the environment highlight its intricate works.

LINKS:

Information on grass spiders from bugguide.net

Guide to common Bay Area spiders