Orb Weaving Spiders: Family Araneidae
While Araneidae species may rank among the most easily recognized group of spiders in the world, common knowledge about Araneidae just about stops with those facts.
Stopping there would be a mistake. Knowing about genera and species diversity within the family may not make for interesting bedtime reading, except at Halloween, but it does make for some interesting spider facts.
A few of the more interesting orb weaver facts are presented below.
All Araneidae do not spin webs. Spiders in the genus mastophora, commonly called bolas spiders, did not receive the Araneidae web spinning memo. Instead, they use a spun silk line to catch their favorite moth prey.
Recent research suggests that the Araneidae family dates back to the Jurassic Era (206-144 million years ago). From then to now, Arachnologists and spider enthusiasts have documented 2847 Araneidae species, placed withing 167 genera. Taken together, the family "ranks third (out of 110) in terms of number of described spider species.
Speaking of numbers, the The Journal of Arachnology recently published a key to "Genera of Arenid Orbweavers of the Americas" saying, there are 65 genera and about 1,500 different species found from South America, north to Canada.
Finally, according to the book, The Orb-weaving Spiders of Canada and Alaska, the number of Araneidae genera and species decreases the further north one goes.
There are approximately 30 genera and 165 species of Araneidae north of Mexico, but only 19 genera and 62 species in Canada. The United States has over one hundred more Araneidae species than Canada.
The links in the box point to articles covering twelve of the most common genera in the family. The Araneus, Argiope and Spotted Orbweavers are probably the most common orbweavers found in residential areas.
© 2008 Patricia A. Michaels