The Effects of Temperature and Body Mass on Jump Performance of the Locust Locusta migratoria

Abstract

Locusts jump by rapidly releasing energy from cuticular springs built into the hind femur that deform when the femur muscle contracts. This study is the first to examine the effect of temperature on jump energy at each life stage of any orthopteran. Ballistics and high-speed cinematography were used to quantify the energy, distance, and take-off angle of the jump at 15, 25, and 35°C in the locust Locusta migratoria. Allometric analysis across the five juvenile stages at 35°C reveals that jump distance (D; m) scales with body mass (M; g) according to the power equation D = 0.35M 0.17±0.08 (95% CI), jump take-off angle (A; degrees) scales as A = 52.5M 0.00±0.06, and jump energy (E; mJ per jump) scales as E = 1.91M 1.14±0.09. Temperature has no significant effect on the exponent of these relationships, and only a modest effect on the elevation, with an overall Q10 of 1.08 for jump distance and 1.09 for jump energy. On average, adults jump 87% farther and with 74% more energy than predicted based on juvenile scaling data. The positive allometric scaling of jump distance and jump energy across the juvenile life stages is likely facilitated by the concomitant relative increase in the total length (L f+t; mm) of the femur and tibia of the hind leg, L f+t = 34.9M 0.37±0.02. The weak temperature-dependence of jump performance can be traced to the maximum tension of the hind femur muscle and the energy storage capacity of the femur's cuticular springs. The disproportionately greater jump energy and jump distance of adults is associated with relatively longer (12%) legs and a relatively larger (11%) femur muscle cross-sectional area, which could allow more strain loading into the femur's cuticular springs. Augmented jump performance in volant adult locusts achieves the take-off velocity required to initiate flight.

Take-off speed in jumping mantises depends on body size and a power limited mechanism

“…The agreement between the prediction of a power constrained model and the correlation between body mass and take-off velocity thus indicates that the primary constraint on the take-off velocity is the amount of power generated by the muscles. Once airborne, however, wind resistance would reduce jump distance depending on the size and mass of the insect (Bennet-Clark and Alder, 1979; Snelling et al, 2013; Vogel, 2005b). …”

Impact of Different Developmental Instars onLocusta migratoriaJumping Performance

“…Results show that force, acceleration, takeoff velocity, and kinetic energy, except power output, varied as an exponential function of body mass. Furthermore, a study on the effect of body mass and temperature on the jumping performance of L. migratoria indicates that jump energy scaled with body mass with a mean exponent of 1.15 across ontogeny and was otherwise unaffected by ambient temperature in the range of 15-35°C [39]. The energy stored by L. migratoria adults increases disproportionately from fifth instars and is greater over characterizing jumps of young instars, supporting results achieved on S. gregaria [29].…”

“…A few researches focused on ontogenetic locomotion development in invertebrates, and they specifically investigated the ontogenetic jumping performance of locusts [28,29,32,34,[39][40][41][42][43][44][45]. However, little has been reported about the configurations of hind legs during the takeoff phase in locusts of different instars and their potential effect on the jumping performances.…”

The Effect of Ground Type on the Jump Performance of Adults of the Locust Locusta migratoria manilensis: A Preliminary Study

“…Hawlena et al [18] reported that the chronic risk of predation can increase both the take-off speed and the jump distance of grasshoppers and that this pattern cannot be explained by morphological variation. Air resistance reduces the kinetic energy of locust jumps by less than 10% at lower initial speeds [19], and environmental temperatures ranging from 15 • C to 35 • C only weakly affect jump energy [20]. The properties of the ground are another set of environmental factors that can potentially affect the locust jump, especially during the take-off stage.…”