The Colour and the Shape: Morphological Variation on a Facultatively Eusocial Bee Augochlora (Augochlora) amphitrite (Schrottky)

Abstract

Augochlorine bees exhibit a large array of foraging and social behaviors, nest substrates and architecture. The huge diversity of behaviors is frequently linked with morphological traits. All levels of variation should be analyzed in order to provide a broader view of evoluton. Augochlora (Augochlora) amphitrite Schrottky occurs from northern of Argentina to southeastern of Brazil. The species nests in decaying wood and is facultatively eusocial. Color variation and head polymorphism were already mentioned in the literature and the main goal of the present paper is to evaluate the morphological variation of the species. For this purpose, we examined 720 specimens and carried out qualitative and quantitative analyses with traditional morphometrics. Other 25 Augochlora species were studied and we propose a revised diagnosis for A. amphitrite. A remarkable color variation is described, there are three morphs: green, dark blue, and black. There are no geographical patterns linked with the color variation. We propose that Odontochlora lethe Schrottky and Odontochlora styx Schrottky are junior synonyms of Odontochlora amphitrite Schrottky. Those names refer to black male and female occurring within A. amphitrite distribution. There is a continuous variation on size and shape of head. Again, we do not fi nd any relation of morphology with distribution. Besides gena swelling, the adductor ridge of mandible is strongly developed on macrocephalic females. Due variations showed, A. amphitrite is a bee candidate to be a model for studies to link morphology, function and behavior.