Spider Information

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Phylum, Arthropoda; Class, Arachnida; Order, Araneae

Identifying Features

Appearance (Morphology)

  • Quite variable, colors from dull grays, browns and blacks to bright reds, yellows and greens.
  • Two body regions: cephalothorax and abdomen
  • Cephalothorax bearing up to eight simple eyes and four pair of legs, divided by thin segment leading to the abdomen which may have one to four pair of spinnerets (finger-like structures), on the posterior end.
  • A pair of appendages near the mouth called pedipalps, either leg-like or bulbous, depending on sex.

Adult Males and Females
Male pedipalps usually enlarged, looking like boxing gloves.

Immatures (different stages)
Spiderlings are smaller than the adults, but basically look the same. Cloration of immature spider may be different than adult

Natural History

Food
Spiders are predators that eat various other arthropods, usually smaller than themselves. Common prey include crickets, flies, bees, grasshoppers, moths and butterflies.

Habitat
If a web builder, the nest is usually near where insects will fly, like near flowers or moist areas. Some web spinners build their nest on the ground to catch walking insects and arthropods. A retreat area may be just off the web in a crevice, rolled leaf, or twig. Species that burrow into soil may situate nests under a log, rock or in a crevice. The jumping spiders do not make webs, but actively hunt for prey.

Predators
Some wasps, other spiders, birds and lizards.

Interesting Behaviors
Spiders produce silk which they use to build webs, capture prey, float through the air (ballooning), enclose their egg sac and line burrows. This unique material and its use in trapping prey are noteworthy characteristics of spiders. Mating rituals of spiders may be very elaborate.

Impact on the Ecosystem

Positive
Spiders help manage insect populations by eating lots of insects. Medical research using spider venom has yielded several chemicals that may be useful to control or treat diseases in humans.

Negative
The spider's bite may cause pain but in most cases, the venom is usually harmless. Avoid using black widow spiders and brown recluse spiders in classroom and field study. Their venom can cause more adverse reactions in humans than other types of spider venom.

Collecting Live Insects

Where to find
Spiders build webs in shrubs, trees, along rock walls, storage rooms and in corners. Many spiders live in a retreat area off the web. Burrowing spiders may be found under rocks, logs, in debris or old litter. Be cautious of black widow spiders whose webs are strong and sticky. If they are in your area they are common in storage areas, under plants and under sheets of wood or cardboard.

How to collect
To collect spiders that have spun a web: either wear heavy gloves and gently remove the spider from out of the web or use a stick and swirl in the web to trap the spider and use forceps to gently remove the silk from around the captured spider; or locate the retreat area and remove the spider either by gently coaxing the spider out or wait until night when the spider may come into the middle of the web; or since spider eyes reflect light, you can easily locate them at night by shining a flashlight and looking for the "glow" from their eyes, then place a container over them and collect. Collect spiders that burrow when they are wandering around at night. These spiders may be fast runners, so be prepared to watch for rapid movement. If you can see the hole of the burrow, block it with a rock so that the spider cannot retreat. Gently coax the spider into a coffee can or jar using a stick or gloved hand.

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Lesson Plans Information Sheets Rearing Sheets Bibliography
Center for Insect Science Education Outreach The University of Arizona
Contact:CISEO
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