Friday, May 28, 2010

Jumping Spider (Tutelina elegans)

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Tutelina is a small genus of very interesting American salticids that deserve much more study. These spiders, which themselves seem to be generalized ant mimics, readily attack and feed upon small ants. It is generally unusual for ant mimics to attack ants, as more often the spiders are Batesian ant mimics.

This is a young male. The males have a very interesting double mohawk style hairdo that is quite something to behold. This one is just starting to grow, notice the little white tufts on the sides of his head. The females are a pretty emerald green, and I really like their flashy yellow striped legs.

Raynox DCR-150 and Raynox DCR-250, stacked and mounted on my Panasonic Lumix FZ8.

Saturday, May 22, 2010

Zebra Jumping Spider (Salticus scenicus)

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I find a bunch of these guys around, by far the most common jumpers I encounter. I can find two or three with just a two minute walk around my deck door. That being said, this is the first male I've found. You would think out of the dozens I've photographed before I'd find at least one, but no, this is my first.

I've been looking for a male for the longest time because just look at those fangs! The chelicerae are elongated, and jointed, and a nice pair of fangs comes out of them. They're so big that this guy actually looks a little clumsy when he moves.

Very personable little buggers too, they'll crawl all over you, and look up every few seconds. I'm certain they recognize my eyes.

The Zebra Jumping Spider is a common household jumping spider. Like other jumping spiders, it does not build a web. It uses its four pairs of large eyes to locate prey and its jumping ability to pounce and capture it. Zebra spiders are often noted for their 'curiosity' when observed by humans; many seem aware of their audience and seem to respond to observation by raising their heads and studying the observer.

Raynox DCR-150 and Raynox DCR-250, stacked, and mounted on my Panasonic Lumix FZ8

Tuesday, May 18, 2010

Wolf Spider (Trochosa terricola)

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I found this spider cleaning out some of the brush alongside my garage. It was a fairly large specimen, about 3/4" in diameter. It was also a fair bit slower than the normal wolf spiders I run into. I would almost say it moved at a lumbering pace. It didn't seem very afraid of me, or particularly aggressive either.

Wolf spiders are members of the family Lycosidae. They are robust and agile hunters with good eyesight. They live mostly solitary lives and hunt alone. Some are opportunistic wanderer hunters, pouncing upon prey as they find it or chasing it over short distances. Others lie in wait for passing prey, often from or near the mouth of a burrow.

Their eyes reflect light well, and one method of finding them is to hunt at night using a flashlight strapped to one's forehead so that the light from the flashlight is reflected from their eyes directly back toward its source. This is also especially helpful because the wolf spiders are nocturnal and will be out hunting for food, making it easier to find them.

Because they depend on camouflage for protection, they do not have the flashy appearance of some other kinds of spiders. In general their coloration is appropriate to their favorite habitat.

Raynox DCR-250 mounted on my Panasonic Lumix FZ8

Saturday, May 15, 2010

Bold Jumping Spider (Phidippus audax)

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Phidippus audax, my favorite species of Spider. I really love them, in a weird Steve Irwin kind of way.

Phidippus audax are a common jumping spider of North America. They are commonly referred to as the Bold Jumping Spider. The average size of adults ranges from roughly 3/8 to 3/4 inches in body length, though I have found several in Texas around the 1" mark. Yes, body length of 1". It's true, everything is bigger in Texas.

These spiders are typically black with a pattern of spots and stripes on their abdomen and legs. Often these spots are orange, yellow or red tinted in juveniles, turning white as the spider matures. I think they look like a smiley face.

The Bold Jumping Spider belongs to the genus Phidippus, a group of jumping spiders easily identified both by their relatively large size and their iridescent chelicerae. In the case of P. audax, these chelicerae are a bright, metallic green or blue. From the pic above, you know what chelicerae are now.

These spiders have been known to jump up to 50 times their own body length, and the male may jump away during mating if the female approaches too quickly.

Like other jumping spiders, due to their large, forward facing eyes, they have very good stereoscopic vision. This aides them when stalking prey, and allows some visual communication with others of their species, such as courting 'dances'.

While this guy may look very menacing, he's really only about 3/8 inch long. A curious little bugger too.

Raynox DCR-250 mounted on my Panasonic Lumix FZ8.

Saturday, May 1, 2010

Female Triangulate Cobweb Spider (Steatoda triangulosa)

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The adult female Triangulate Cobweb Spider is 1/8 to 1/4 inch long, with a brownish-orange cephalothorax and spindly, yellowish legs. The round, bulbous abdomen is creamy in color, with parallel purply-brown zigzag lines running front to back. This distinctive pattern sets it apart from other Theridiids in its area.

The triangulate cobweb spider is known to prey on many other types of arthropods, including ants (including fire ants), other spiders, pillbugs, and ticks. It preys on several other spiders believed to be harmful to humans, including the hobo spider and the brown recluse.

The egg sac of the triangulated cobweb spider is made from loosely woven silk, and is about the same size as the spider itself. Each egg sac contains approximately 30 eggs.

In common with other members of the Theridiidae family, S. triangulosa constructs a cobweb, i.e. an irregular tangle of sticky silken fibers. As with other web-weavers, these spiders have very poor eyesight and depend mostly on vibrations reaching them through their webs to orient themselves to prey or warn them of larger animals that could injure or kill them. They are not aggressive. Other, larger members of the Steatoda genus do have medically significant bites, but there are no recorded bites or envenomations by this spider.

S. triangulosa is a cosmopolitan species, and is found in many parts of the world, including much of North America, southern Russia, New Zealand and Europe. The spider is believed to be native to Eurasia. This species is primarily a house spider, and builds webs in dark corners of buildings and other man-made structures.

Raynox DCR-250 mounted on my Panasonic Lumix FZ8.