Morphological adaptations to the parasitic life in Polistes sulcifer and P. atrimandibularis (Hymenoptera Vespidae)

Abstract

The results of a morphological and morphometric comparison between two species of Polistes obligate social parasites and their two respective host species are reported. Some parts of the body of the parasites were found to be larger than those of their hosts. Probably, such morphological traits are an advantage to the parasites during the nest invasion fights, e.g. the size of the mandibles which they use as a weapon against the foundress and workers.

The lack of morphological modifications due to the reduction or loss of some activities and/or behaviours suggest that Polistes social parasites should not be considered as having attained a high degree of parasitic specialization.

KEY WORDS:

• Polistes
• social parasitism
• morphology