Wolf spider (family Lycosidae)
Wolf spiders belong to the family Lycosidae, a large and
widespread group that is found throughout the world. They are named for
their wolflike habit of chasing and pouncing upon prey. About 125
species occur in North America, whereas there are about 50 in Europe.
Numerous species occur north of the Arctic Circle. Most are small to
medium-sized. The largest has a body about 2.5 cm (1 inch) long and legs
about the same length. Most wolf spiders are dark brown, and their
hairy bodies are long and broad, with stout, long legs. They are noted
for their running speed and commonly occur in grass or under stones,
logs, or leaf litter, though they may invade human dwellings that harbor
insects. Most species build silk-lined, tubular nests in the ground.
Some conceal the entrance with rubbish, whereas others build a
turretlike structure above it. A few species spin webs. Wolf spider eggs
are contained in a gray silk sac attached to the female’s spinnerets,
or silk-producing organs, so that she appears to be dragging a large
ball. After hatching, the young spiders ride on the mother’s back for
several days.
Although the spider is not considered to be aggressive, it will often bite people in self-defense. Wolf spiders are venomous, but their bites are not considered dangerous. (Some bite victims who are allergic to spider bites in general may become nauseous, dizzy, and develop an elevated heart rate, however.). The spider’s large fangs cause physical trauma at the site of the bite. The bite itself has been described as similar to that of a bee sting, and the venom the spider injects may cause itchiness at the site. This painful bite, coupled with their speed and startling appearance, can be unsettling, and some bite victims panic from the experience.
Although the spider is not considered to be aggressive, it will often bite people in self-defense. Wolf spiders are venomous, but their bites are not considered dangerous. (Some bite victims who are allergic to spider bites in general may become nauseous, dizzy, and develop an elevated heart rate, however.). The spider’s large fangs cause physical trauma at the site of the bite. The bite itself has been described as similar to that of a bee sting, and the venom the spider injects may cause itchiness at the site. This painful bite, coupled with their speed and startling appearance, can be unsettling, and some bite victims panic from the experience.
Wolf spiders are members of the family Lycosidae, from the Ancient Greek word "λύκος"
meaning "wolf". They are robust and agile hunters with excellent
eyesight. They live mostly solitary and hunt alone. Some are
opportunistic hunters pouncing upon prey as they find it or even chasing
it over short distances. Some will wait for passing prey in or near the
mouth of a burrow.
Wolf spiders resemble Nursery web spiders (family Pisauridae), but wolf spiders carry their egg sacs by attaching them to their spinnerets (Pisauridae carry their egg sacs with their chelicerae and pedipalps). Two of the wolf spider's eight eyes are large and prominent, which distinguishes them from the Nursery web spiders whose eyes are all of approximately equal size. This can also help distinguish them from grass spiders.
There are many genera of wolf spider, ranging in body size (legs not included) from less than 0.4 to 1.38 inches (10 to 35 mm).[1][2]
They have eight eyes arranged in three rows. The bottom row consists of
four small eyes, the middle row has two very large eyes (which
distinguishes them from the Pisauridae),
and the top row has two medium-sized eyes. They depend on their
excellent eyesight to hunt. They also possess an acute sense of touch.
Flashing a beam of light over the spider will produce eyeshine. The light from the flashlight has been reflected from
the spider's eyes directly back toward its source, producing a "glow"
that is easily noticed. This is also especially helpful because the wolf
spiders are nocturnal and will be out hunting for food, making it
easier to find them. Wolf spiders possess the third best eyesight of all
spider species, bested only by jumping spiders of the order Salticidae (who can distinguish colors) as well as the huntsman spiders.
Wolf spiders are unique in the way that they carry their eggs. The
egg sac, a round silken globe, is attached to the spinnerets at the end
of the abdomen, allowing the spider to carry her unborn young with her.
The abdomen must be held in a raised position to keep the egg case from
dragging on the ground. However, despite this handicap, they are still
capable of hunting. Another aspect unique to wolf spiders is their
method of infant care. Immediately after the spiderlings emerge from
their protective silken case, they clamber up their mother's legs and
crowd onto her abdomen.
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.
Hogna is the genus with the largest of the wolf spiders. Among the Hogna species in the U.S., the nearly solid dark brown H. carolinensis (Carolina wolf spider) is the largest, with a body that can be more than one inch long. It is sometimes confused with H. helluo, which is somewhat smaller and different in coloration. The underside of H. carolinensis is solid black, but the underside of H. helluo is variegated and has reds, oranges, and yellows with shades of black.
Some members of the Lycosidae, such as H. carolinensis, make deep tubular burrows in which they lurk much of the time. Others, such as H. helluo,
seek shelter under rocks and other shelters as nature may provide. They
may wander from place to place, and are therefore more likely to be the
ones attracted into human habitation when the weather starts to turn
colder in autumn.
There are many smaller genera of wolf spiders such as those found in the United Kingdom. They live in pastures and fields and feed on smaller prey, playing an important role in natural population control that keeps insect numbers in the wolf spiders' vicinity within acceptable levels.
Wolf spiders resemble Nursery web spiders (family Pisauridae), but wolf spiders carry their egg sacs by attaching them to their spinnerets (Pisauridae carry their egg sacs with their chelicerae and pedipalps). Two of the wolf spider's eight eyes are large and prominent, which distinguishes them from the Nursery web spiders whose eyes are all of approximately equal size. This can also help distinguish them from grass spiders.
Contents
Description
Eye configuration of a Hogna species
Eyeshine in led lamp light
Wolf spider carrying her young
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.
Hogna is the genus with the largest of the wolf spiders. Among the Hogna species in the U.S., the nearly solid dark brown H. carolinensis (Carolina wolf spider) is the largest, with a body that can be more than one inch long. It is sometimes confused with H. helluo, which is somewhat smaller and different in coloration. The underside of H. carolinensis is solid black, but the underside of H. helluo is variegated and has reds, oranges, and yellows with shades of black.
Female UK wolf spider
There are many smaller genera of wolf spiders such as those found in the United Kingdom. They live in pastures and fields and feed on smaller prey, playing an important role in natural population control that keeps insect numbers in the wolf spiders' vicinity within acceptable levels.
Venom
Wolf spiders will inject venom if continually provoked. Symptoms of their venomous bite include swelling, mild pain and itching. In the past, necrotic bites have been attributed to some South American species, but further investigation has indicated that those problems that did occur were probably actually due to bites by members of other genera.[3] Australian wolf spiders have also been associated with necrotic wounds, but careful study has likewise shown them not to produce such results.[4]Habitats
Wolf spiders can be found in a wide range of habitats both coastal and inland. These include shrublands, woodland, wet coastal forest, alpine meadows, suburban gardens, and homes. 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 left open or have a trapdoor (depending on species). Arid zone species construct turrets or plug their holes with leaves and pebbles during the rainy season to protect themselves from flood waters.Honoraria
The Carolina wolf spider (H. carolinensis) is the Official State Spider of South Carolina. Designated as such in 2000, South Carolina is the only U.S. state that recognizes a state spider.[5]Gallery
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Wolf spider, 3" from toe to toe (Takoma Park, MD)
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Wolf spider carrying her egg sac
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Wolf spider with offspring (Germany).
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Wolfspider carrying offspring,Australia.
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Wolf spider carrying her young.
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Burrowing wolf spider defending its egg sac.
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Wolf spider carrying egg sac
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Wolf Spider in Maricopa City, Arizona, roughly 25 mm (0.98 in) while legs were retracted
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Large Wolf Spider with young in Michigan.
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Large Carolina Wolf Spider; Hogna carolinensis
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Wolf Spider in Delray Beach, FL.
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Wolf spider (Rabidosa sp.) carrying egg sac under abdomen for protection
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Wolf spider, Greenwood, Missouri
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Wolf spider from central Florida
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Wolf spider having a grasshopper snack Melisochori, Greece
Footnotes
- "Wolf Spiders: Lycosidae Sundevall 1833". Australasian Arachnology Society. Retrieved 2 October 2008.
- Spiders of North America, D. Ubick et al., p. 164
- Ribeiro, L. A.; Jorge, M. T.; Piesco, R. V.; Nishioka, S. A. (1990). "Wolf spider bites in São Paulo, Brazil: A clinical and epidemiological study of 515 cases". Toxicon 28 (6): 715–717. doi:10.1016/0041-0101(90)90260-E.
- Isbister, Geoffrey K.; Framenau, Volker W. (2004). "Australian Wolf Spider Bites (Lycosidae): Clinical Effects and Influence of Species on Bite Circumstances". Clinical Toxicology 42 (2): 153–161. doi:10.1081/CLT-120030941.
- http://www.statesymbolsusa.org/South_Carolina/CarolinaWolfSpider.html
See also
- List of spiders associated with cutaneous reactions
- List of Lycosidae genera
- List of Lycosidae species
References
- Platnick, Norman I. (2008): The world spider catalog, version 8.5. American Museum of Natural History.
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