Social Habits of Some Canary Island Spiders

During the summer of 1925, while I was visiting the Canary Islands with my friend, Dr. David Fairchild, as a guest of Mr. Allison V. Armour on his yacht, the "Utowana," my attention was attracted by /he peculiar gregarious or social behavior of two species of spiders, Cyrtophora citricola Forsktl and Argyrodes argyrodes Walker. The former was described and figured from the Canary Islands by Lucas as early as 1843 under the name of Epeira cacti-opuntice. Simon showed that this spider is the same as Cyrtophora opuntice Dufour, but in his later work he adopts for it an earlier name, Cyrtophora citricola Forskl. He cites it as occurring in Corsica, Provence, Spain, Algeria, Sicily, Syria and the Island of Runion "on cactus, aloes and more rarely on lentiscus." He also gives a brief but accurate account of its web and egg-cocoons, but says nothing about its social proclivities. In the former of the works cited (Vol. V, 1881 p. 16) Simon also mentions Argyrodes argyrodes as living "llke a parasite on the web of Cyrtophora opuntice, more rarely on the web of Epeira adianta, Argiope lobata and Holocnemus rivulatus," and as inhabiting Corsica, Spain, Algeria, Sicily, St. Helena, Madagascar, etc. Lucas merely records C. citricola from the Canary Islands, without mentioning particular localities. I saw both it and the Argyrodes on three of the islands, namely Teneriffe, Palma and Gran Canaria, but failed to find either of them on Lanzarote.