FAMILY ARANEIDAE
THE ORB-WEAVERS

James Beck

Jbeck@arches.uga.edu


General:

The family Araneidae is a member of the order Araneae (Foelix, 1982). The Araneidae include the spiders who spin the elaborate webs most often seen . Araneids are one of the most successful of the spider families; they have over 2,500 species described. The spiders vary greatly in size as well, some species of Singa are about 2 mm in length while some of the Nephila can grow to over 50 mm, even killing small birds(Mafham, 1988). Because of this great variety of species a great variety of orb web designs exists. The Araneids are not the only family of spiders which spin webs. Two other families, the Uloboridae and the Tetragnathidae, also spin webs. However, the construction of their webs differ. The Araneid's webs are studded with glue droplets while the others are not (Foelix, 1982).

Key:


Behavior:

Spiders in the family Araneidae will demonstrate several different strategies of predation. Some will immediately wrap their prey in the web then bite; some will wrap, move, then bite; while others will just seize their prey with their chelicerae, move them to the hub of the web, and then wrap up their prey. These diffenent strategies are used on different insects usually due to the relative strength of the prey (Foelix, 1982). The members of this family will exhibit a wide variety of social behavior(Milne, 1995)

Enemies:

Spiders are spiders most common enemy; however, other types of organisms will attack spiders as well. The wasp Episyron rufipes attacks mostly Araneids. The spider is stung by the wasp and an egg is layed on its abdomen. Later, when the larva hatches it will feed on the spider until it dies.

Habitat:

These spiders are very common all over the world and will be found in woods, caves, grasses and almost any other habitat imaginable(Milne, 1995).

Here is a listing of all genus under the family Araneidae (Platnick, 1989)



When trying to identify a species in this family it can be very difficult, because there are so many different species in this family. A single identification guide or key would be hard to come by. One of the most common and user friendly is "National Audubon Society's Feild gudie to North American insects & spiders". Try this book, or any key book at your local library. If this fails inlist the help of a trained entomologist.




References

Other links:
OUR ECOLOGY CLASS
The U.S. E.P.A. (See what is our government is doing about our environment.)
The National Park service (Have some fun!!!)