home *** CD-ROM | disk | FTP | other *** search
- Spiders are the largest group of arachnids.
- There are more then 34,000 named species
- worldwide, including 3,000 species in
- North America.
- Spiders can easily be identified by their
- 4 pairs of legs. Each leg is segmented
- into many different sections or joints.
-
- Most Spiders have 8 pairs of eyes. A few
- have less then 8 and some species have
- none at all. The eyes of a spider are
- usually arranged in 2 or 3 rows.
- Spiders usually have 6 silk glands called
- spinnerets located beneath the abdomen.
- Not all spiders spin webs, some live in
- burrows which they line with silk.
- Spiders are not considered insects. They
- are from the order of Araneae. (Arachnids)
- Insects have only 6 legs, whereas spiders
- have two more for a total of 8 altogether.
- All spiders are predators. They feed mostly
- on insects, but some of the larger species
- prey on small animals!
-
- There is a common mistake most people make
- about the 'Daddy Long Legs'. This is not
- actually a spider at all, it is classified
- in the order or 'Opiliones'.
- Tarantulas (Family Theraphosidae)
- Certain South America species are deadly
- poisonous, but the bite of a North American
- Tarantula is as dangerous as a bee sting.
- There are some male spiders that release
- long silken strands, which they use like
- parachutes to float in the wind to another
- location.
- Black Widow Spider (Latrodectus mactans)
- Of all spiders, the Black Widow is the most
- feared. The female's venom is especially
- poisonous to people.
- The Fishing Spider (Dolomedes tenerosus)
- If disturbed this spider can go below the
- water and remain motionless for 30 minutes.
- Air trapped by his body allow him to breathe.
- Like all arachnids, spiders have an abdomen
- and a cephalothorax. These are separated
- by a waist or pedicel. The thorax is
- protected by a covering called a carapace.
- Most spiders lay eggs in silken sacs. Some
- place the egg sac in their webs, while others
- attach it to twigs and leaves. A few spiders
- carry the sac with them at all times.
- Spiders should be considered very beneficial
- to us because they help keep the enormous
- insect population like mosquitoes in check.
-
- The correct term for a newly hatched spider
- is a spiderling. The young, though smaller,
- resemble their adults from the moment they
- emerge from their egg sac.
- Contrary to what most people think, only a
- few spiders actually bite people, and the
- venom of most of these is quite harmless.
-
- Tarantulas (Family Theraphosidae)
- Male Tarantulas are short-lived, yet females
- have been known to live for as many as 30
- years !
- Trapdoor Spider (Family Ctenizidae)
- These spiders nest in tubelike burrows they
- dig into the ground. They seal the nest with
- a hinged lid similar to a folding trapdoor.
- Spitting Spiders (Family Scytodidae)
- There are many types of Spitting Spiders.
- They have spitting glands within the thorax
- which make a sticky substance to catch prey.
- American House Spider (Achae. tepidariorum)
- These spiders spin irregular webs made of
- sticky strands. When these webs catch dust
- and dirt they become 'Cobwebs'.
- Black Widow Spider (Latrodectus mactans)
- Male Black Widow Spiders do not bite. After
- they mate, the female often eats the male
- spider earning her the name 'Widow'.
- Hammock Spider (Pityohyphantes costatus)
- These spiders get their name from the
- hammock like sheet web they construct
- between fence posts and tree branches.
- Orb Weaver Spiders (Araneaus spp.)
- Like most spiders who spin webs, they
- construct a new web each night. They spin
- the web in complete darkness by touch alone!
- Barn Spiders (Araneus cavaticus)
- These spiders stay in their webs at night
- to wait for prey. In the daytime, they move
- above it and are attached by a silk line.
- The Shamrock Spider (Araneus trifolium)
- This spider waits at the side of his web
- between grass stems. They make a tent to
- hide it by tying leaves together with silk.
- The Shamrock Spider (Araneus trifolium)
- Their webs are made each night in the grass.
- They can be clearly seen with the dew at
- sunrise. At night they eat the old one.
- Bola Spider (Mastophora bisaccata)
- This spider catches prey by producing a
- silken line which has drop on the end that
- that resembles the South American Bola.
- Wolf Spiders (Family Lycosidae)
- This spider lives in burrows and seldom
- emerges from them. They lie in wait for
- prey ready to pounce on a passing insect.
- Burrowing Wolf Spiders (Geolycosa spp.)
- These spiders construct vertical burrows in
- sand several feet deep. They cement the
- sand with silk to make the walls sturdy.
- Ant-mimic Spiders (Castianeira spp.)
- These spiders usually live near anthills.
- Their look and antlike behavior helps them
- to confuse predators.
- Goldenrod Spider (Misumena vatia)
- This spider 'Flower Spider' changes its
- to yellow which allows it to camouflage
- itself on Goldenrod and daisies.
- Jumping Spiders (Family Salticidae)
- There are many different types of Jumping
- Spiders. They get their name from the
- spectacular leaps catching their prey.
- Jumping Spiders (Family Salticidae)
- These spiders have the sharpest vision of
- all spiders. When they leap onto their prey,
- their spinnerets create a silken dragline.
- Many spiders who spin webs do not wait
- in them for prey. They attach themselves
- to the web by a silk line which senses
- the vibrations of a struggling insect.
- Species of spiders that spin webs each have
- a distinctive pattern. Some are shaped like
- funnels, some are round, and others are
- zigzagged.