Wednesday, April 17, 2013

WOLF SPIDER

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 lives 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 spider. There are many genera of wolf spider, ranging in body size from less than 1 to 30 millimetres (0.04 to 1.18 in).[1] 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, Wolf spiders are capable of defensive bites, and some South American species may give bites that are medically significant. Nevertheless, the presence of wolf spiders is considered favorable to some because they consume undesirable arachnids.[2] Wolf spiders will inject venom freely 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.

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