The Spotted Predatory Katydid or Chlorobalius leucoviridis is a large aggressive species found throughout the arid interior of Australia that makes use of mimicry to catch its prey.
Images copyright D. Marshall & K. Hill.
This species feeds on a wide range of prey items including flies, grasshoppers, cicada's and other katydid species . Rentz (1995) found that prey are held in the long spiny forearms and disabled via a bite to the throat. What is interesting about this species is its ability to successfully mimic the female response call to male Cicada's, luring him within range to be preyed upon. Marshal & Hill (2009) found that the Katydid was able to mimic the species-specific wing clicks produced by sexually receptive females in response to males. Furthermore they also mimic the Cicada's visually with a series of body jerks. This combination of both visual and auditory mimicry has led to the Katydid becoming a very successful predator. The katydid however only responds to the calls of cicadas during daylight. Male cicadas are vocal throughout the evening but the Katydids ignore the calls of their prey after dark and instead focus on their own intraspecies communication
Interestingly Marshall & Hill (2009) found that the Katydid will respond to the calls of male Cicada species to which they have never been exposed- that is species that do not occur in their geographical area. They hypothesis that the mechanism that has driven the Katydids ability to mimic is hardwired to species that use a duet calling system.
References:
Marshall, D Hill, K 2009, 'Versatile aggressive mimicry of cicadas by an Australian predatory katydid', Plos One, vol. 4, no. 1, pp. e4185.
Rentz, D 1995, 'Do the spines on the Legs of Katydids Have a Role in Predation? (Orthoptera: Tettigoniidae: Listroscelidinae)', Journal of Orthoptera Research, vol. 08/1995, no. 4, pp. 199-200.
Marshall, D Hill, K 2009, 'Katydid Predation', Photo, Encyclopedia Of Life, viewed 17 May 2014. <http://eolspecies.lifedesks.org/node/3522>
Fascinating! How similar in size are these two species? Based on the pictures, the katydid looks huge in comparison, so the cicada must be “blind” to size indeed! Do other species of katydids use aggressive mimicry too? What do you mean when you say that the katydids ability to mimic is “hardwired” to species? Cool post.
ReplyDeleteHi Tasmin,
ReplyDeleteIt is odd isn't it with the size difference, however the body jerking has only been observed in the katydids when responding to cicada's, that is they don't do it when communicating among themselves suggesting it is targeted to the cicadas! By Hardwired i man that the mechanism that allows mimicry is specifically targeted towards duet calling species.