Biological and Behavioural Features of the Stenogastrinae (Hover Wasps) in a Particular Evolutionary Route to Eusociality in the Family Vespidae

In the family of Vespidae there are examples of social evolution that are particular, compared to those found among other social insects. The characteristics of eusociality are, however, found only in three subfamilies, those of Stenogastrinae, Vespinae and Polistinae, but the problem of whether eusociality appeared one or two times has long been debated. Biomolecular analysis studies have definitively demonstrated that the Stenogastrinae are the representatives of a social lineage completely independent from that of the Polistinae and the Vespinae. In the present paper, I want to emphasize the various phenotypic characteristics, especially studied by the group for the study of social insects of the University of Florence, which make these social wasps different from the others.