Relationships among cannibalism, contact signals, ovarian development and ecdysteroid levels in Tegenaria atrica (Araneae, Agelenidae)

The present investigation was designed to study the relationships between the reproductive state of Tegenaria atrica females and their agonistic behavior towards conspecific females. Our results show that the virgin females exhibit the lowest levels of agonistic behavior whereas they provoke the highest levels of cannibalism by the mated females. The virgin females can be clearly distinguished from the other females as regards synthesis/release of cuticular compounds: methylesters and hydrocarbons. Furthermore, the ovaries of these females have not yet started vitellogenesis and the haemolymphatic ecdysteroids levels are high. It appears that the variation of females cannibalism parallels ovarian development and could be related to changes in cuticular compounds. Our results show for the first time that changes in spiders sexual and parental behavior during the reproductive cycle are accompanied by characteristic modifications in cuticular compounds, ovarian development as well as haemolymphatic ecdysteroid levels.