David Element's Wildlife Web Page Orthopteroids 12

David Element

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Orthopteroids 12 - Great Green Bush Crickets 1

GREAT GREEN BUSH CRICKET Tettigonia viridissima (Nymph)

GREAT GREEN BUSH CRICKET Tettigonia viridissima (f)

A partial life history of the Great Green Bush Cricket is shown. Once seen, this huge insect will not be easily forgotten. The lower two photographs illustrate an adult female taken in southern France. The sturdy and slightly decurved ovipositor is clearly illustrated. This is the largest species of Bush Cricket in the UK although it is only found in the South. However, it is very common in Europe, producing amazing crepuscular/nocturnal choruses in the marshlands of northern France that are even audible from a speeding train! The stridulation (song)* produced by all male British Bush Crickets (with the exception of the Oak and Southern Oak Bush Crickets) is generated by rubbing the toothed stridulatory ridge on the left forewing against a 'scraper' on the right forewing. Despite its size this species can be frustratingly difficult to locate as it is extremely well camouflaged against the vegetation in which it lives. The stridulation of the Great Green Bush Cricket is very loud and distinctive, carrying quite some distance (up to 50 metres), but when one closes in on the cricket the exact source of the sound is hard to find. The stridulation is ventriloquial and it may be necessary to search for the insect at some length before actually seeing it! In order to pinpoint the exact position it is sometimes helpful for the observer to listen with alternate ears directed towards the presumed origin of the noise and then split the difference. This ploy also works for several other species, particularly Roesel's Bush Cricket.

*An excellent account of the stridulatory mechanisms of Orthoptera may be found in 'GRASSHOPPERS AND CRICKETS OF SURREY', DAVID W. BALDOCK, SURREY WILDLIFE TRUST, 1998. ISBN 0 9526065 4 2 - see: http://www.surreywildlifetrust.co.uk/ for further information about the Surrey Wildlife Atlas series. This comprehensively illustrated book contains reproductions of the song diagrams (for Surrey species, i.e. the substantial majority of the British fauna) originally published in 'GRASSHOPPERS, CRICKETS AND COCKROACHES OF THE BRITISH ISLES' by David Ragge. This second book is unfortunately out of print, but for those with an interest in identification by sound there are tape cassettes and CDs available - *see Orthopteroids 1 for further information. Experienced observers wil develop the ability to read the song diagrams and develop the skills requiired to identify these insects without actually seeing them in much the same way as a birdwatcher can identify birds by their songs or calls. This is a very useful tool for performing site surveys when available field study time may be limited.