Synchronized and rhythmical activity during the prey capture in the social spiderAnelosimus eximius (Araneae,Theridiidae)

Summary Anelosimus eximius is a social spider species of South America. Many individuals share the same web and participate in prey capture, taking some ten seconds to locate the prey in the silky structures. In the laboratory, we analyzed the movements of each spider which took part in the pursuit, and showed that they were both synchronized and rhythmical. Spiders alternate simultaneous periods of immobility (involving 100% of the attacking individuals) and activity (involving at least 70% of the spiders).The results are discussed with reference to the model developed by Goss and Deneubourg (1988) suggesting that autocatalysis may be the motor of certain synchronized and rhythmical activities in social arthropods.