Field observations were made on Bubopsis agrionoides, Puer maculatus and Deleproctophylla dusmeti (Ascalaphidae) in the Mediterranean area of France. B. agrionoides and P. maculatus were found in the biotopes covered with Quercus ilex, whereas D. dusmeti was collected in open areas covered with low vegetation. Individuals of B. agrionoides and D. dusmeti regroup to constitute populations of variable importance, but individuals of P. maculatus were always observed solitarily. The daily activity period of the adults was determined only for B. agrionoides and D. dusmeti. Like the Libelloides species, the three species mentioned in this paper may use the dorso-frontal UVsensitive part of their divided compound eyes for detecting preys or mates flying on blue sky background.