|Female Great Green Bush-cricket with large ovipositor|
It has felt like a good summer so far with my tanned legs unrecognisable from the white etiolated versions that last year’s damp squib created. This exposure to the sun has been extended this year by traditional scything and hay-making on our new plot of land. One of the benefits of such a manual approach is the closer intimacy it affords to the land and greater observation of any emerging wildlife. I have been impressed by the volume and variety of invertebrates caught in the process and have tried to leave a large enough patch for them to continue to thrive. This week I was pleasantly startled by the leap of a viridescent grasshopper. On closer inspection it proved to be a Great Green Bush-cricket (Tettigonia viridissima), characterised by its large size, distinctive colouration and very long antennae - hence this group of Orthopterans previously referred to as ‘long-horned grasshoppers’(Chinery, 1977). The top image shows an adult female with its threatening-looking down-curved ovipositor, but this is simply its egg-laying tool.Bush crickets are more nocturnal than grasshoppers and so predatory bats become a much greater threat, particular species that can tune in to the insects song. It would appear however that Tettigonia viridissima is not quite a soft target and has developed some clever avoidant strategies by monitoring the echolocation calls of hunting bats. Schulze and Schul (2001) showed by experiments that the crickets varied their responses based on the intensity of the bats echolocation, from ‘steering away’ at low levels to a ‘sudden dive’.
So here’s hoping for the summer weather to continue and the cricket to keep playing for a while longer before my legs morph back to wan winter wickets.
Chinery, M (1977) A Field Guide to the Insects of Britain and Northern Europe. London: Collins.Schulze, W. and Schul, J. (2001) Ultrasound avoidance behaviour in the bushcricket Tettigonia viridissima (Orthoptera: Tettigoniidae). The Journal of Experimental Biology 204: 733–740