Floral oil collection by male Tetrapedia bees (Hymenoptera: Apidae: Tetrapediini)

Abstract

Several groups of solitary bees, known as oil-collecting bees, gather lipids from flowers that offer them as their main reward to pollinators. In the Neotropical region, oil-collecting bees belong to the tribes Centridini, Tapinotaspidini, and Tetrapediini (Apidae: Apinae). The floral oils collected by females of these groups are used as larval food or in nest construction. The interaction of these bees with oil flowers is characterized by the presence of specialized structures for oil collection on the legs that morphologically match the location and type of the oil-producing glands on flowers they visit. In addition, these bees have specialized arrays of setae (including the scopae) for oil transport. In a few genera, both sexes display such specialized structures, although floral oil collection has hitherto been regarded as an exclusively female task. Here, we report floral oil collection by males of Tetrapedia, a Neotropical genus of oil-collecting bees. We describe behavioral aspects of oil foraging by males, present data on morphological structures associated with the collection of this resource, and discuss potential hypotheses to explain the significance of floral oils in the mating system of Tetrapedia.