First published online March 28, 2008
Journal of Experimental Biology 211, 1317-1325 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.015354
The effect of leg length on jumping performance of short- and long-legged leafhopper insects
M. Burrows* and
G. P. Sutton
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ,
UK
View larger version (93K):
[in this window]
[in a new window]
|
Fig. 1. Body form of short and long-legged leaf hoppers. (A) Side view of the
short-legged Ulopa standing on its host plant Erica. (B)
Side view of short-legged Cephalelus on its host plant
Restio. (C) Side view of long-legged Graphocephala
fennahi.
|
|
View larger version (84K):
[in this window]
[in a new window]
|
Fig. 2. Scanning electron micrographs of Ulopa to show the key structures
of the hind legs for jumping. (A) The proximal joints of the middle and hind
legs viewed ventrally. The hind coxae extend the width of the metathorax and
are apposed at the ventral midline; the middle coxae are more widely
separated. The right hind leg is in the levated position ready for jumping;
the left hind leg is depressed. Anterior is to the top. (B) The femoro-tibial
joint of a hind leg viewed from its lateral side showing the lack of
specialisations for jumping and the absence of femoral spines. (C) The
tibio-tarsal joint of a hind leg viewed ventrally to show the semi-circular
array of spines.
|
|
View larger version (26K):
[in this window]
[in a new window]
|
Fig. 3. Drawing of a ventral view of Cephalelus to show the structures
involved in jumping. The right hind leg is levated at the coxo-trochanteral
joint and the tibia partially flexed about the femur. The left hind leg is
fully depressed and extended, and its distal parts are omitted. The middle
legs are rotated forwards to reveal the trochantin of each hind leg. Anterior
is to the top.
|
|
View larger version (32K):
[in this window]
[in a new window]
|
Fig. 4. Images of a jump by Ulopa viewed from the side. The images at the
times indicated are arranged in two columns with the bottom left hand corner
providing a constant reference point in this and in Figs
5,
6. The first movements of the
hind legs (arrow) began 1.2 ms before take-off. The front and middle legs
(arrows) lost contact with the ground before take-off. After take-off the body
began to rotate backwards about its longitudinal axis. Images were captured at
5000 s–1 and with an exposure time of 0.05 ms.
|
|
View larger version (49K):
[in this window]
[in a new window]
|
Fig. 5. Images of a jump by Cephalelus viewed from the side and captured
at 5000 s–1 and each with an exposure time of 0.03 ms. The
first movement of a hind leg occurred 2 ms before take-off (arrow). The front
and middle legs (arrows) lost contact with the ground before take-off. After
take-off the body began to rotate around its longitudinal axis. The lines on
the first frame (–2.2 ms) indicate how the angle between the head and
the pronotum was measured.
|
|
View larger version (29K):
[in this window]
[in a new window]
|
Fig. 6. Jumping in Cephalelus. (A,B) Placement of the hind tarsi and leg
movements in a jump. (A) Two frames from a jump toward and to the right of the
camera. The hind tarsi were placed on the ground lateral to the left and right
edges of the body (arrows) and remained in that position at take-off. (B) A
jump from the vertical, glass front of the chamber viewed from underneath. The
tarsi of the hind legs (arrows) are again placed outside the lateral outline
of the body and thus do not touch. The first movements of the hind legs began
2 ms before take-off. Images were captured at 5000 s–1 and
with an exposure time of 0.03 ms. (C) Drawings of the hind legs of
Cephalelus to show their movements during the three phases of a
jump.
|
|
View larger version (21K):
[in this window]
[in a new window]
|
Fig. 7. Trajectories and velocities of five jumps by Ulopa. (A)
Trajectories of five jumps. The images of Ulopa at the times
indicated are from the jump plotted as the diamond symbols and show that it
rotated around both its longitudinal and transverse axes. (B) Velocity of the
same five jumps, each plotted as a three-point rolling average against time,
of a point on the body roughly corresponding to its centre of gravity and
indicated by the cross on the cartoon in A.
|
|
View larger version (17K):
[in this window]
[in a new window]
|
Fig. 8. Trajectories and velocities of five jumps by Cephalelus. (A)
Trajectories of five jumps. (B) Velocities of the same five jumps, plotted as
a three-point rolling average against time, of a point on the body indicated
by the cross on the cartoon. Peak velocity, measured as in
Fig. 7, was reached less than 1
ms before take-off.
|
|
View larger version (9K):
[in this window]
[in a new window]
|
Fig. 9. Length of the hind legs and jumping performance in short- and long-legged
leaf hoppers. (A) Length of hind legs is not correlated with take-off velocity
[peak take-off velocity averaged across a number of jumps (see
Table 2) for each species]. The
two short-legged leaf hoppers are plotted as open squares; the six long-legged
species as filled circles. (B) Leg length is linearly correlated with take-off
time. The same species as in A are shown, together with three unidentified
long-legged species (open circles). Both data fits were generated with a
standard linear regression.
|
|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
© The Company of Biologists Ltd 2008
