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beetles

140519-0621

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.

140519-0623The 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!

There’s more about spider evolution at Wikipedia. There’s also a neat article about trigonotarbids.

140519-0625

When I find a beetle I don’t recognize, usually the first book I open is Evans and Hogue’s beautiful beetle guide, which is part of the excellent series of California natural history guides from University of California Press.

Of the various beetle books in my library, this one seems to have the most comprehensive section of color photos, with more than 300 nicely composed images.

According to the blurb on the back cover, the book covers 569 of the 8,000 or so species of beetles in California, but almost all of the beetles I’ve found in the last few years can be identified by flipping through the color photos. Unfortunately (and this is my only criticism) the color plates do not include page numbers for the beetles illustrated, which means one must look up the species in the index to find the text description. Oh well, it only takes a moment to find the page.

If you love beetles as much as I do and you live in California (or even if you don’t!) this handy guide might become one of your most valued references.

If you choose to purchase Field Guide to Beetles of California (California Natural History Guides) through the Amazon link in this sentence you will be supporting my ecogarden work by adding a few shiny new pennies to my account balance.