Meeting Abstract
A natural environment contains an abundance of sensory stimuli. To generate adaptive behavioral responses to those stimuli, animals must quickly identify salient features, assign them an attractive, neutral, or aversive value, and ignore background noise. We investigated whether two species of Drosophila, native to visually distinct environmental landscapes, demonstrate varied visuomotor reflexes. Previous studies have shown that while D. melanogaster, native to forested areas with complex visual scenes, fixate long, thin bar-like objects that emulate landing perches, assigning these objects an attractive value; in contrast, they will steer away from smaller, box-like objects that mimic predators, for an aversive assignment (Maimon et al., 2008). Cactophilic D. mojavensis, however, originate from the Baja California-Mojave Desert regions with sparse visual scenery. We asked whether the size-correlated value assignments D. melanogaster assign are conserved across species by examining D. mojavensis. To investigate this question, we used a ‘virtual-reality’ flight simulator to present visual objects that D. melanogaster consider aversive (small box) or attractive (long stripe) and presented them to tethered flying D. mojavensis while analyzing their steering behaviors. We found that unlike D. melanogaster, D. mojavensis steer towards small box-like objects. Additionally, D. mojavensis steer more robustly and find objects in elevated regions of their field of view to be more salient. These results reveal a previously unknown diversity in visuomotor processing among species of Drosophila and suggest that two closely-related species perform inverse behaviors in response to the same visual stimuli.
