Meeting Abstract
Praying mantises, which are often ambush and cryptic predators, rely on the rapid movements of three segments (coxa, femur and tibia) of an exaggerated foreleg to capture prey. The predatory strike of a praying mantis has been characterized into two stages, the approach, which positions the mantis to strike; and the sweep, the actual strike. Previous research has characterized the general movements of the foreleg, suggesting that the sweep and some of the movements of the foreleg are stereotypical and that strike speed increases with prey distance. However, the amount of variation in the kinematics of the individual segments, including their relative angles and velocities, has not been well examined. In this study we further describe the kinematics of the exaggerated forelegs of the praying mantis strike and examine the patterns of variation in relation to the prey position. We analyzed 58 feeding strikes from 8 ghost praying mantises (Phyllocrania paradoxa) within instar 6 (juveniles) filmed at 1000 Hz. We addressed several questions: 1) is the variation in the approach time different than the sweep time, 2) is there a relationship between predator-prey position and foreleg velocity and 3) are kinematics of the foreleg segments consistent? We found: 1) more variation in the approach time than the sweep time, 2) only femur velocity is related to predator prey angle, and 3) mantises modulate their strikes by adjusting the percent of their arms versus their body used in the strike and by changing the angle of the coxa. Our results suggest that while certain aspects of the strike are stereotypical, such as sweep time and some joint angles, other traits, such as approach time and percent of body and arms used during the strike are modulated based on prey position.
