Jumping behaviour in a Gondwanan relict insect (Hemiptera: Coleorrhyncha:Peloridiidae)

Abstract

SUMMARY Jumping by a relict insect, Hackeriella veitchi (Hacker 1932),belonging to the ancient Coleorrhynchan line that diverged from other Hemiptera in the late Permian, was analysed from high-speed images captured at rates of 2000 s–1 and from its anatomy. This 3 mm long,flightless insect weighs up to 1.4 mg and can jump by rapid movements of the hind legs that accelerate the body in 1.5 ms to a take-off velocity of 1.5 m s–1. This performance requires an energy expenditure of 1.1μJ and a power output 0.74 mW, and exerts a force of 1.24 mN. It achieves this with a body design that shows few specialisations for jumping compared with those of other groups of Hemipterans such as the froghoppers or leafhoppers. The hind legs are only 10% longer than the front and middle legs by virtue of longer tibiae and tarsi, and are only 65% the length of the body. The main thrust for a jump is provided by the rapid rotation of the fused trochanter and femur about the coxa of a hind leg, in a movement that forces the hind tarsus against the ground and raises the body to take off. In some jumps the two hind legs move together, but in others the movements may not be closely synchronised, thereby imparting a rotation on the body that is maintained once airborne. When the time difference is larger, the rapid movement of just one hind leg results in the insect falling from its perch in an adaptive escape response.

Jumping mechanisms of treehopper insects (Hemiptera, Auchenorrhyncha, Membracidae)

“…The shortest acceleration times occur in planthoppers and froghoppers, with take-off being achieved in about 0.8ms in Issus and Philaenus. The smallest treehoppers take longer, 1.2ms, comparable to the time taken by fleas (Sutton and Burrows, 2011) and short-legged leafhoppers , but shorter than the 2ms taken by Hackeriella (Coleorrhyncha) (Burrows et al, 2007) and pygmy mole crickets (Burrows and Picker, 2010). Heavier treehoppers take correspondingly longer so that their acceleration times of 2-3.7ms overlap with those of some long-legged leafhoppers (2.75-6.4ms).…”

“…) are higher than those of snow fleas at 0.8ms −1 , Hackeriella (Coleorrhyncha) at 1.5ms -1 (Burrows et al, 2007), fleas at 1.9ms Bennet-Clark and Lucey, 1967;Sutton and Burrows, 2011), shore bugs Saldula at 1.8ms…”

“…Both arrangements occur within the four sub-orders of the Hemiptera that contain many prodigious jumpers. In three of these groups the hindlegs move in separate planes at the side of the body: Coleorrhyncha (Burrows et al, 2007); Heteroptera (Burrows, 2009b); Sternorrhyncha (Burrows, 2012).…”

Jumping performance of flea hoppers and other mirid bugs (Hemiptera, Miridae)

“…The best take-off velocities in shore bugs were twice as high compared with even the smallest mirids and were reached in acceleration times that were half as long. Catapult mechanisms have also been implicated to explain the jumping performance of a coleorrhynchan bug (Burrows et al, 2007), of Sternorrhynchan jumping plant lice (Burrows, 2012) and of all the auchenorrhynchan species so far analysed (Table 3). For froghoppers and planthoppers, which belong to the last group, these inferences have been confirmed by recordings from muscles during jumping (Burrows, 2007b;Burrows and Bräunig, 2010).…”

“…In the three other hemipteran suborders, only a few jumping species have been analysed in detail but all are judged to use a catapult mechanism from the measured power requirements of their jumps; in the Heteroptera, one species of shore bug (Saldidae) (Burrows, 2009b), in the Coleorrhyncha, one species of Hackeriella (Peloridiidae) (Burrows et al, 2007) and in the Sternorrhyncha, three species of psyllids (Pysllidae) (Burrows, 2012).…”