Theridion

Taxobox
name = "Theridion"

---

image_caption = male "T. sisyphium"
image_width = 250px
regnum = Animalia
phylum = Arthropoda
classis = Arachnida
ordo = Araneae
subordo = Araneomorphae
familia = Theridiidae
genus = "Theridion"
genus_authority = Walckenaer, 1805
diversity_link = List of Theridiidae species#Theridion
diversity = nearly 600 species
range_

range_map_width = 250px
subdivision_ranks = Species
subdivision = "T. attritum"
"T. grallator"
"T. nigroannulatum"
"T. strepitus"
"hundreds more, see text."

The spider genus "Theridion", after which the family Theridiidae is named, consists of almost 600 described species that occur all around the world.

Notable species are the Hawaiian happyface spider ("T. grallator"), and "Theridion nigroannulatum" which is one of the very few species of spiders which live in social groups and not merely aggregate by coincidence. They live in large colonies, lying in wait for passing prey purportedly concealed under the edge of a leaf or stick with threads trailing down beneath them. If an insect intrudes, interjecting itself into the web, the spiders respond en masse, overwhelming it as a team. They even take turns helping pull large victims back to their lair.

"Theridion braueri" Simon, 1898 probably belongs into a different genus; however, "Robertia" the new name proposed by Saaristo (2006) is preoccupied.

pecies

External links

* [http://www.newscientist.com/article.ns?id=dn9820&feedId=online-news_rss20 Society-focused spiders live and hunt together] - NewScientist.com