Spiders, just in time for Halloween
I was sorry to see that the first thing that comes up when Googling “spider” is how to get rid of them. While I understand people not wanting to share their living space with spiders, I admire the adaptability of a creature that can live in deserts and ice caves, at sea level and 20,000 feet up on Mount Everest, and can travel hundreds of miles by air without wings by ballooning.
In appreciation of their role as predators, I always catch them if they come indoors and escort them outside where they can eat 2,000 insects a year in my garden.
Fall is the best time to look for spiders as they have been getting bigger all summer and are now easier to spot, especially the larger females. A foggy morning is the easiest time to find their webs.
Coyote brush is especially attractive to insects now because it is a source of nectar when other sources are gone in the fall.
Spiders are grouped by whether they spin a web or hunt, and by the type of web they spin. The ones that spin a “classic” spider web are orb weavers. There are also sheet web spiders, which include the filmy dome spider, a common spider in Marin with a web shaped like an igloo, and the aptly name bowl and doily spider. Then, there are trapdoor spiders, funnel webs spiders and others.
One common spider in Marin is the labyrinth or condominium spider (genus Metepeira). These spiders typically spin webs in close proximity to other spiders, often in coyote brush. Coyote brush is especially attractive to insects now because it is a source of nectar when other sources are gone in the fall.
The web looks like a messy tangle, but if you mist it with a spray bottle, the orb web becomes visible. The orb is below and in front of the tangle. The spider— whichmay emerge to check out the spray — is in a retreat made of leaves and debris in the tangle part of the web.
Some people mistake the retreat for prey that has been wrapped up. There is a line from the retreat to the orb web to alert the spider when prey is snared.
Another spider with a hiding place is the debris spider (genus Cyclosa), which hides in plain sight in a line of debris in the web. It is small, less than one-fifth of an inch, and is often hard to see in the line of exoskeletons of prey, bits of plants and other debris, unless it gets scared and moves. If you get a good look, you will notice the unusual conical abdomen. This spider also utilizes the line of debris to hide its eggs. I frequently see them in Samuel P. Taylor State Park, but they are in many other places, including Point Reyes, China Camp and Mount Tamalpais State Park.
Cross spiders (Araneus diadematus) are also common in the fall, and their 10-inch orb webs are easily spotted. They are found in every state in the United States, as well as Canada and Europe, so they are sometimes called European garden spiders. They are brown and tan orb weavers with a white cross formed by white dots and dashes on their backs. (Sometimes the horizontal part of the cross is not clear.) They have bumps reminiscent of the shoulder pads popular in the 1980s.
Cross spiders can grow
to 4/5th of an inch, although they are often smaller. I have seen them in many places including Tennessee Valley, Bolinas Ridge, Indian Tree Open Space, Mount Tamalpais, Point Reyes and even the path between Hal Brown Park and Bacich Elementary School.
If your child has told
you the common myth that daddy longlegs — a common name often misapplied to the very common Pholcus phalangoides, more correctly called a cellar spider — is the most venomous spider in the world but its fangs cannot pierce human skin, I hope you will correct this slander. The truth is that their venomhas a weak effect even on small insects.
Happy Halloween!