DANG, P/D; VINCENT, S/E; LAILVAUX, S/P; IRSCHICK, D/J; Tulane Unversity; Tulane Unversity; Tulane Unversity; Tulane Unversity: The role of body size in orthopteran jumping mechanics

Although previous studies have examined the mechanics of the orthopteran jump, no studies have examined jumping in very large species to test for potentially negative influences of body size on jump kinematics or performance. We addressed this issue by filming (at 500 fps) adult males and females of the large Lubber grasshopper (Romalea guttata) jumping from a force platform. Despite females (12g) being twice as heavy as males (6g), males had relatively longer legs (body-size adjusted) than females. Additionally, we did not detect any sexual dimorphism in jump kinematics or performance. The jump of the Lubber can be characterized as having a long extension period (630 ms), slow leg angular velocities (2222 degrees s^-1), high mass-specific power outputs (667 W kg^-1) and high maximum jump velocities (13.7 m/s). Unlike other orthopteran species, the maximum velocity was achieved just prior to landing, not take-off. These data show that Lubbers perform relatively more work per unit time to accelerate their heavier center of masses than smaller orthopteran species.