Meeting Abstract

55.2  Tuesday, Jan. 5  Accommodation of antennal perturbation in freely flying hawkmoths DICKERSON, BH*; HEDRICK, TL; University of North Carolina at Chapel Hill; University of North Carolina at Chapel Hill bradley.dickerson@alum.swarthmore.edu

In recent years, studies of animal flight have expanded beyond the basic aerodynamic mechanisms required for flight force generation to include issues of sensory integration and robust flight performance. Sane et al. (2007) demonstrated that the antennae of the hawkmoth Manduca sexta act as mechanosensors and detect Coriolis forces, essentially serving as gyroscopes and helping the moths maintain a stable orientation. However, many questions remain regarding the function and capabilities of the antenna-gyroscope, including the degree to which moths may accommodate damage to the sensory apparatus by changing biomechanical properties of the system and the consequences of sub-lethal damage to flight performance. We examined these questions by comparing the vibration frequency, inter-antenna angle and whole body roll-pitch-yaw orientation and temporal variation in these parameters between intact moths and moths with the distal 50% of each antenna amputated. We hypothesized that the loss of mass would reduce vibrational amplitude in treatment moths, leading to deficits in orientation stability marked by greater variation in roll, pitch and yaw. However, we expected the control and treatment moths would maintain similar (and constant) inter-antennal angles. Preliminary data analysis supports the last of these, but also revealed no change in antennal vibration amplitude, suggesting that treatment moths were able to relax the antenna joint to achieve similar bending under a different load regime. Orientation stability at short time scales was also unaffected by partial antennectomy, but treatment moths experienced occasional drastic failures in pitch, indicating that the accommodation to sensor damage was ultimately insufficient to preserve free-flight function.