Morphology of the Sternal Glands of Polistes Fuscatus and P. Canadensis (Hymenoptera: Vespidae)

Although 13 exocrine glands have been located in wasps of thegenus Polistes, and 12 in Mischocyttarus (Landolt and Akre, 1979),their morphology and functions have been little studied. Recently,however, the sternal gland on the sixth gastral (terminal) segment offemales of these wasps has attracted attention because its secretion isrepugnant to some species of ants. Female wasps rub the secretiononto the nest petiole, thus forming a chemical barrier againstpredatory ants (Jeanne, 1970; Hermann and Dirks, 1974; Turillazziand Ugolini, 1978, 1979; Post, 1980)