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wasps

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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.

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This beautiful little wasp poses on an avocado leaf with a fuzzy salvia flower for added color. Yellow and purple and green are so nice together!

This could be a paper wasp in the genus Polistes, possibly the common European paper wasp (P. dominula) but I’m not certain. Her abdomen is a little too yellow, with black stripes too narrow. But there are variants in the species and there are also other kinds of paper wasps.

Paper wasps are some of the most streamlined, beautiful wasps. They are fairly docile unless you mess with them or with their nests. They often appear in this garden among dried stems, using their mandibles to chew off cellulose-rich material for their hanging, cooperative, hex-celled, papery brood homes.

Here’s another post about a beautiful wasp.

As the weather cools and the rains begin, the garden explodes into glorious color. There’s a lot happening here. Let’s take a tour!

In the foreground just left of center, a Leonotus bush pokes up tall stems bearing bursts of orange flowers. It’s a drought-tolerant bush from South Africa that is well-loved by pollinators.

At the far left, a Pyracantha shrub also pushes up tall stems, bent down by huge bunches of bright red berries. Before I took over this garden it was a huge, dense, unhappy, unhealthy, never-blooming, spherical monstrosity, frequently shaped by evil gardeners with their noisy gas-powered trimmers. I violently chopped it right down to stumps (what fun that was!) and it grew back. Now it is a noble creature of beautiful form, whose berries are just getting to the point where the birds will feast. Much better, don’t you think?

Against the wall in back is a large and happy princess flower (Tibouchina urvilleana) which drops its crazy purple petals all over the walkway. It’s related to geraniums.

In the middle ground behind the Leonotus is a huge, dense bush of Salvia, possibly S. nemorosa. Its abundant purple flower stalks are serious food sources for black carpenter bees, honey bees, various flies, wasps, and of course our local hummingbirds. What a contributor!

To the extreme right, a few bright orange flowers shine from among the dark green leaves of a cape honeysuckle bush (Tecoma capensis). Another African native, this plant used to be a huge, scraggly beast struggling in the deep shade of a magnolia tree that is no longer there. I chopped it right back down to the ground, and now the new growth is being severely pruned as needed so that it is no more than a few feet high. Nonetheless, it is happy and showing lots of buds and flowers, which the hummingbirds are enjoying.

UPDATE: A closer look at this tamed giant.

Although it shows no brilliant color other than green, I must also mention the avocado sapling poking up at right of center, between the  cape honeysuckle and the Leonotus. Just a few months ago it was a small sprout with only a few glossy green leaves. Soon, it will be the tallest plant in the garden. My plan is to let it grow tall, but to prune off the lower branches. That way its remaining lowest branches will eventually shade the currently summer-sun-blasted bank below the fence (off the picture at the left) while its lack of lower growth will allow the sun to still bless the rest of the garden. Maybe in some years it will even start dropping edible fruit.

What a joy it is to watch the seasons change in the deep nature garden!

She was flitting around in the sedge patch, maybe looking for just the right kind of long, thin, green, grassy leaves to tear into tiny strips and use in her nest. This is a sphecid wasp in the genus Isodontia, possibly I. mexicana, although we are a bit north of their normal range. These are commonly known as grass carrier wasps. There are a half dozen or so species in the US, all of which look very similar. To identify one of these little beauties right down to species, one might have to examine genitalia, body bristles or the exact arrangement of wing veins.

These shapely little wasps seek out small orthopterids (mostly crickets and katydid or grasshopper nymphs) which they paralyze with their sting and stuff into the nest, where their larvae can feed on them safely. Depending on the species, nests can be in vegetation or in burrows in the ground, sometimes in the abandoned burrows of other insects.

You can learn more about Isodontia grass carrier wasps at Discover Life’s page for the genus. There are also some nice pages with pictures at Bug Guide.

Taking good pictures of this lively predator was tough indeed, as she was constantly moving. The last shot was a lucky one, an action pose just at the split second she took off and flew away. Adios, little friend…