Tuesday, August 17, 2010

Dark Fishing Spider (Dolomedes tenebrosus)

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Fishing spiders are similar to the larger wolf spiders in size, shape, and coloration. Species in the genus Dolomedes  are called fishing spiders because most live near water and have been reported to catch small fishes and aquatic insects from the water as they walk on the surface. The species  Dolomedes tenebrosus  is more frequently associated with wooded areas (it would be more accurately classified as a tree-dwelling spider) and is a common household invader in these locations. It occurs from New England and Canada south to Florida and Texas.

I found this one on a river bank while I was catfishing.  I caught this one, but missed a larger one when it dropped down into the water and ran away downstream.  They can really move like lightning!

D. tenebrosus  is a fairly large spider. The females are 15 to 26 millimeters in length; males are 7 to 13 millimeters. Both sexes are brownish-gray in color with black and lighter brown markings.

Dolomedes tenebrosus  are frequently found far away from water, usually in wooded settings. They hibernate as immature adults (penultimate instar) under stones or loose bark, in tree cavities, and in human-made structures.  D. tenebrosus  matures in the spring and will subsequently mate. Mature individuals may be found from early May through September. The egg cases are deposited in June and are carried around by the females until the spiderlings are ready to hatch. Young spiderlings may be found from July through September. The young are guarded by the female in a nursery web and may number 1,000 or more.

Raynox DCR-150 mounted on my Panasonic FZ8.

Saturday, July 10, 2010

Two Banded Ant Mimic (Castianeira cingulata)

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While out fossil hunting today I happened upon this gal. While it doesn't look it from this angle, from above it looks just like a Carpenter Ant. It moves along slowly and purposefully like any other ant, except this is a spider.

Members of the genus Castianeira are considered mimics of large ants, such as carpenter ants, and mutillid wasps, which are known as “velvet ants.” These spiders purposely walk about slowly the way ants do and then only move fast when disturbed. Many times they even raise their front two legs to mimic ant antennae.

These spiders mimic ants for several reasons. Many birds or predators that rely on sight to hunt, don't hunt ants because they are typically distasteful or aggressive. Ant mimics may also use their camouflage to hunt ants. A wolf in sheep's clothing!

Raynox DCR-250 mounted on my Panasonic Lumix FZ8.

Monday, June 21, 2010

Dimorphic Jumping Spider (Maevia inclemens)

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Maevia inclemens is a relatively common and colorful jumping spider of North America. Sometimes it is referred to as the Dimorphic Jumping Spider or Blackbodied Jumping Spider.

The species' common name refers to the two different male forms that occur: One is black with yellowish small tufts of black hair on the cephalothorax. The second form, which is grayish with red, white and black markings, resembles the female, which has faint V-shaped markings and a paler abdomen. I really like the yellow palps and zebra striped legs on this little male.

This species is common in the USA. It ranges from New England south to Georgia and west to Nebraska and Oklahoma. It is also found in parts of Canada, for example in southern Quebec.

M. inclemens is the type species for the genus Maevia. The species name is derived from Latin inclemens "cruel, harsh".

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

Saturday, June 19, 2010

Wolf Spider (Hogna helluo)

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This is Hogna helluo. It is the second largest species of wolf spider in the United States. I've been looking for one of these for the longest time, and today while I was out fossil hunting, I found one. This gal was about the size of a half dollar, about an inch and a half in diameter, including legs. Definitely the largest wolf spider I have ever seen.

The carapace of Hogna helluo is characterized by a clearly defined medial stripe from a point between the middle pair of eyes nearly to the point at which the carapace joins the abdomen. The abdomen has a broader light stripe with a darker narrow and tapering form like the head of a lance or a stone arrow point. The underside of the cephalothorax is solid black, but the underside of the abdomen may be spotted with lighter colored patches.

This species does not dig tunnels but may create shelters under rocks and similar natural features. H. helluo frequently enters houses with the arrival of lower temperatures in autumn. They are inside only in search of warmer temperatures and make every possible effort to stay away from people.

Raynox DCR-150 mounted on my Panasonic FZ8.

Friday, June 18, 2010

Barn Funnel Weaver (Tegenaria domestica)

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Generally I have to go out looking for the spiders I photograph, but this one was an exception. As I was doing some laundry, this one ran right over my foot. It was pretty large, about the size of a quarter, and very fast.

These spiders are often found in darker areas, such as flower beds, wood piles, and areas where they can weave a funnel-web. When it is found in homes, it often is found in the basement, in the darker recesses such as closets and corners. It is a nocturnal spider, so generally it is discovered when the lights are turned on and the spider darts for cover. These spiders are not seasonal, but rather, can be found year round, if in a survivable environment.

This species was imported from Europe into the shipping ports when large numbers of settlers immigrated from Europe (starting around the 1600s), and it has steadily spread throughout the United States and Canada.

This spider is not dangerous to people, but is often confused with the Hobo Spider of the same genus, (Tegenaria agrestis), which may or may not be dangerous to humans. Unless you live in the northwest US, it's probably not a Hobo Spider. Look here for the Hobo Spider's natural range. If you are unsure of the exact species, just be mindful of this confusion, and use caution when dealing with the spider.

Raynox DCR-250 mounted on my Panasonic Lumix FZ8.

Thursday, June 17, 2010

Cobweb Spider (Steatoda borealis)

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The spider genus Steatoda, in the family Theridiidae, includes over 120 recognized species, distributed around the world including many cosmopolitan species which are found among human populations worldwide.

Many spiders of the genus Steatoda are often mistaken for widow spiders (Latrodectus), and are known as false black widows; however Steatoda are significantly less harmful to humans. Steatoda are shaped similarly to widow spiders, with round, bulbous abdomens. However, not all Steatoda species resemble widows – many have distinct coloring, and are significantly smaller than Latrodectus specimens. Some species of Steatoda actually will prey on widows, as well as other spiders which are considered hazardous to humans.

Some members of this genus do have bites which are medically significant in humans (such as S. grossa and S. nobilis), however bites by Steatoda species generally do not have any long-lasting effects. The symptoms associated with the bite of several Steatoda species are known in the medical profession as steatodism; and have been described as a less-severe form of latrodectism (the symptoms associated with a widow spider bite).

In common with other members of the Theridiidae family, the Steatoda spiders construct 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, and most injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched somehow. It is possible that some bites may result when a spider mistakes a finger thrust into its web for its normal prey, but ordinarily intrusion by any large creature will cause these spiders to flee.

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

Friday, June 11, 2010

Male Jumping Spider (Naphrys pulex)

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This is a male Naphrys pulex jumping spider. This spider comes from a tribe named Euophryini, which is spread out all over the world. North America has four described species. In fact its genus name "Naphrys" is actually a contraction for "North American Euophrys".

This is the most widely-distributed Naphrys in eastern North America, found from the East Coast to wooded areas in the tall grass prairies west of the Mississippi River. N. pulex can be very common in mesic hardwood forests, at or near the ground in leaf litter, on rocky outcrops, on bark, or on buildings.

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

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.

Friday, April 23, 2010

Long Legged Sac Spider (Cheiracanthium sp.)

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A Long Legged Sac Spider (Cheiracanthium sp.) I found in my basement. A lot less menacing than it looks, probably only 3/4 of an inch including legs. These are very very common spiders in the house, no doubt you have a few around too. This is a male, you can tell by the large black furry palps. You can see a photo of a female here. The male seems to have much longer legs and a wider carapace.

Several reports classify these spiders as possibly harmful, but real study shows their bites are not poisonous or necrotic to humans.

Raynox DCR-150 mounted on my Panasonic Lumix FZ8. I used a simple styrafoam bowl as a flash diffuser for the lighting. Worked out very well if you ask me.

Friday, April 16, 2010

Wolf Spider (Pardosa sp.)

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Pardosa sp., are also known as Thin-Legged Wolf Spiders. This is a female I caught near my watering hose. It was a fair bit larger than the male I caught earlier, probably twice as large. You can compare this female to a male I caught earlier here. Notice how the male has big black furry palps.

Like all Wolf Spiders they are robust and agile hunters with good eyesight. Check out the eyes on this guy. Wolf spiders can be found in a wide range of habitats both coastal and inland. These include shrublands, woodland, wet coastal forest, alpine meadows, and suburban gardens. Spiderlings disperse aerially and consequently wolf spiders have wide distributions. Although some species have very specific microhabitat needs (such as stream-side gravel beds or montane herb-fields) most are wanderers without permanent homes. Some build burrows which can be opened or have a trapdoor. Arid zone species construct turrets or plug their holes with leaves and pebbles during the rainy season to protect themselves from flood waters.

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

Tuesday, April 13, 2010

Wolf Spider (Pardosa sp.)

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Pardosa sp, are also known as Thin-Legged Wolf Spiders. I find they are very common along lake shores, which is where I caught this guy. There were literally dozens of these guys running around. Very, very fast. I initially thought they were jumping spiders, because none of them ran, they all jumped in 2-3" increments. This is a male, you can tell by the large furry black palps.

Like all Wolf Spiders they are robust and agile hunters with good eyesight. Check out the eyes on this guy. Wolf spiders can be found in a wide range of habitats both coastal and inland. These include shrublands, woodland, wet coastal forest, alpine meadows, and suburban gardens. Spiderlings disperse aerially and consequently wolf spiders have wide distributions. Although some species have very specific microhabitat needs (such as stream-side gravel beds or montane herb-fields) most are wanderers without permanent homes. Some build burrows which can be opened or have a trapdoor. Arid zone species construct turrets or plug their holes with leaves and pebbles during the rainy season to protect themselves from flood waters.

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