Date of Award
Bachelor of Science
dragonfly, insects, stimuli, target
The dragonfly is a visual predator that feeds on small flying insects. Because of their high rate of hunting success, dragonflies must have the ability to efficiently discern prey and predator from natural surroundings. In this study, we investigated the extent to which visual flight-control neurons in dragonflies are able to differentiate stimuli that simulate prey items from those that simulate predators. To do this, we presented fourteen sets of rectangular stimuli varying in height, width, speed, and moved in four directions while recording extracellular neuronal responses from the ventral nerve cord. Each of the rectangular stimulus patterns was moved in two ways: (1) along its long axis (a “worm” stimulus) and (2) perpendicular to its long axis (an “antiworm” stimulus). Our preliminary results show that dragonflies respond best to smaller stimuli, particularly the 4° target, with speed having no significant effect on the neural responses. Further research is necessary and ongoing to determine trends related to changes in stimuli size and velocity.
Lolier, Melanie, "Discerning Prey from Predator in Dragonflies" (2011). Honors Theses. 1022.