Laboratoire de Biologie et Physiologie du Comportement, URA-CNRS 1293, BP 23, Université Henri Poincaré, 54506 Vandoeuvre-les-Nancy, France.
In spiders, some environmental conditions allows such cannibalistic solitary animals to reduce the inter-individual distance. Authors propose that this phenomena has favor a socialization process in some species. In this way, we investigate the relationships between diet availability, agonistic behavior and cuticular compounds in group of the usual solitary spider Tegenaria atrica. Our results show that ad-libitum diet increases the development speed and decreases cannibalism between conspecifics. Juveniles reared in group seem to keep their lack of agonistic behavior during ontogenesis, and adults show an unusual mutual tolerance. No quantitative changes in cuticular compounds were observed with the diet, but with the rearing mode. The decrease of cannibalism in grouped young was correlated with the absence of feeding competition and changes in the synthesis / release of 4 compounds: palmitic acid, 13.17-+11.17-+9.17-dimethylhentriacontane, methyl octadecenoate and n-heptatriacontane. Moreover, the cuticular profile of adults reared in group evolve not towards the usual one observed for solitary individuals. We hypothesis that the socialization process in spiders might be initialized by environmental conditions (such as diet) and favored by a switch in the chemical communication in order to inhibit agonistic interactions.