We have not seen much dew in the Bay Area in this year of record drought, so here’s a reminder that sometimes there is actual moisture around here! On December 24, 2012 the sun lit up this tiny spider web among irises and Santa Barbara daisies.
The spider that spun this web was no larger than a pin head, yet it contained enough instinctive knowledge to construct this complicated, 3-dimensional structure suspended expertly from leaves and stems.
A typical organic garden contains thousands of spiders of many kinds. Most of them remain hidden in the vegetation, actively exploring for prey. Only a few spin webs that are large enough to be easily noticed.
The presence of spiders in the garden is ecologically profound, because they eat a significant fraction of the flying and crawling insects. In webs just like this one in the same garden, I have spotted fungus gnats, parasitic wasps, fruit flies, many other small insects, and even a lady beetle.
There are more than 42,000 kinds of spiders. They have been around for 400 million years, evolving from fascinating little critters called trigonotarbids that looked a little like modern ticks and mites.
Back in those early days there were no dew-spangled spider webs because web-weaving spiders had not yet evolved. True spiders with spinnerets appeared around 300 million years ago during the Carboniferous, a time when yard-long dragonflies cruised the skies. It must have been a great time to evolve predators!