Meeting Abstract
Populations of dragonfly larvae are subject to conspecific predation and heterospecific predation. These predatory larvae have acute perception to motion, usually remaining immobile until potential prey is detected. Likewise, changes in activity level and hiding behavior are common predator avoidance behaviors. We measured larval behavior in the presence of caged conspecific predators, caged heterospecific predators, or in the absence of predators (control) in the field using floating behavioral arenas, with two rock refuges present in each arena. Time spent hiding and activity level per trial were measured for each individual by recording larval position every ten minutes over a two-hour period. Activity level did not vary among the treatments, but we observed a significantly higher percentage of hiding in conspecific treatments compared to heterospecific and control treatments. Dragonfly larvae have excellent vision; thus hiding may be a more effective method than immobility in the face of conspecific predation. If dragonfly larvae are still able to forage effectively near hiding places, then hiding may also be less costly than an overall reduction in activity level.
