Rapid spatial learning in a velvet ant (Dasymutilla coccineohirta)

Abstract

Spatial learning has been examined in a variety of animals to determine what cues are used to navigate through a complex environment. A common feature of previously studied vertebrates and invertebrates is their need to return to a previously visited site for mating, nesting, foraging or predator avoidance. Velvet ants (Hymenoptera: Mutillidae) are cursorial parasitoids with flightless females that must walk through complex terrain to find ground dwelling host larvae burrows. Velvet ants are not central-place foragers (they do not return to an established nest site) so much of the previous work on spatial learning does not directly apply in this context. It was assumed that females primarily use chemosensory cues for navigation and burrow location instead of visual learning. This study, however, demonstrates that velvet ant females are able to use visual landmarks to find an inconspicuous exit in an aversion-motivation spatial learning task. A significant number of velvet ants learned to locate the exit after seven training trials and went to the previous location of the exit even after the maze had been rotated, showing that landmarks external to the maze were used to learn the escape location.