Effets inhibiteurs de la présence d'un congénère sur la maturation des ovocytes chez Acanthoscelides obtectus Say (Coléoptère: Bruchidae)

Abstract

The bean weevil Acanthoscelides obtectus, which is found over a large geographical area, can live in habitats where its host plant is not continuously available throughout the year. In such cases, the females must wait for favorable egg-laying conditions during part of the year. Individuals of this species may concentrate in temporary shelters such as dry leaves for example. The effect of the grouping of two individuals (female and male; female and female) on the reproductive physiology of females from a Cuban strain led to an inhibition or a decrease in oogenesis. This phenomenon was also observed when a female cohabited with a male whose aedeagus had been removed. However, oocyte maturation was stimulated when 4-day-old females were placed in the presence of a male for 4 h. The variability observed between two generations is discussed along with the often neglected role of relationships among individuals. The adaptive role of the inhibition of oocyte maturation induced by the grouping of two individuals is discussed.