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Arizona has many different crab spiders.

We have colorful ones that hide in flowers.

We have gentle giants (Olios sp.).

This week we have a new (to us) crab spider.

It was small spot, a body and legs sunning on a car cover. At first glance, I thought it might be a tick.

A closer look shows it is a spider because it has two distinct body regions. Ticks are basically one oval body.

The forward-directed front legs indicate it is a crab spider.

In fact, it appears to be a ground crab spider, Xysticus sp. (Experts, please correct me).

It's always fun to find something new.

Want to learn a few basics about how to identify spiders? See our previous post.

Or pick up a book from our growing list of children's books about spiders at Science Books for Kids.

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Sometimes simply adding one plant to your yard can attract new insects. This week our Mexican hat or prairie coneflower (Ratibida columnifera) is flowering.

mexican-hat-flower354

Look at all the bugs enjoying the blooms.

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Of course you would expect to see bees visiting flowers.

pollen-coated-bee_0323

This bee was collecting loads of pollen.

beetle-0290Also visiting the flowers were beetles,

lacebug-0311lace bugs,

looper-caterpillar-231and a looper or geometrid caterpillar. Actually, there are two caterpillars in this photograph. Look down and to the left.

tiny-caterpillar-in-focus242Maybe you can see it better in this photograph. It looks like a thread of white on the edge of the petal towards the bottom. It is a first instar or newly-hatched caterpillar.

crab-spider-plus0307Wherever there are bugs feeding on plants, there are predators like this crab spider ready to feed on the bugs.

A friend recently asked for some tips how to identify spiders.

jumping-spider-another1. Leg size and position

Often the length and position of the legs are easy to see and can give you a clue. Jumping spiders like this one have short legs that are tucked up under their bodies.

 

flower-spider

Crab spiders have 2 pairs of long front legs. They hold their front legs out to the side with the tips directed forward.

feather-legged-spider-1

Feather-legged spiders also have extra-long front legs. They hold their first pair of legs directly out front of themselves and pressed together.

wolf-spider-23Wolf spiders have legs that are all roughly the same length and shape, as do a few other groups such as fishing spiders.

2. Web pattern

Some spiders are easier to identify by their webs.

garden-spider-orbOrb weavers (also called garden spiders) produce large complex webs, often across paths.

funnel-web-retreatFunnel web spiders produce sheets of silk around a central, hollow retreat.

3. Eye Pattern

If you can get a good photograph from the front of the spider, the size and position of the eyes can aid in identification.

Let's take a quick look at spider anatomy, in case you are not sure which is the front end.

basic-spider-anatomy

Besides the legs, the other parts you see on the spider are the abdomen (body area covered with red arrows), and the combined head and thorax, called the cephalothorax (body area covered with yellow arrows). The two appendages that surround the mouth are the pedipalps. The pedipalps are at the front end of the spider, with the eyes.  (Note:  in newer scientific texts the abdomen may be called an opistosoma and the cephalothorax called a prosoma).

The eye patterns are distinctive and easy to recognize with a bit of practice.

jumping-spider-face-viewLooking face on at a jumping spider you can see they have two large eyes in the front of their cephalolthorax and two smaller eyes on either side.

jumping-spider-side-view-general

They also have two smaller pairs of eyes further back. See the dark, shiny eye about 1/2 way back on the cephalothorax?

crab-spider-on-purple-100In contrast, the crab spiders have a cluster of tiny eyes right in a oval at the top and front. The eyes in this spider are set into the orange-yellow colored area. You can hardly see the eyes in comparison with those of the jumping spider.

Eye_Arrangement_of_a_Wolf_Spider

(Photograph by Thomas Shahan from USA licensed under the Creative Commons Attribution 2.0 Generic license at Wikimedia.)

Wolf spiders also have two large central eyes, but have a downward-curving row of four eyes below them. They also have another pair further back, which you can just see as a dark curves.

This is only a very basic introduction to spider identification. If you would like to learn more about this, BugGuide has set up an excellent page showing all the different eye patterns in spiders.

Spiders have quite a bit going on and are actually quite fascinating once you get to know more about them.