Tuesday, 24 August 2010

What's this 'ear?

It's was great to go on a nature ramble with these two. Although Jack is just coming up to 10 and Josh is not seven until December, they are both very alert and knowledgeable for their years.

Along with that their keen eyes and ears means that very little is missed. With all this youthful enthusiasm I quickly discovered that they had one thing that I no longer have, and that's the ability to hear very high frequency sounds.

Roesel's bush-cricket (Metrioptera roeseli)

As we walked along Josh kept stopping and showing me Roesel's Bush Crickets hidden away in the long grass. It was a while before I realised that he was finding them by sound and that I was the odd one out in the group, in no longer being able to hear the buzzing song. Well that's not quite true, in ideal conditions, with no noise or wind I could hear them if I was close enough, but I certainly have lost some ability to hear sounds of this frequency. Male crickets and grasshoppers stridulate or ‘sing’ to attract females for mating purposes and each song is characteristic of one species. Grasshopper song is produced by rubbing a row of stridulatory pegs on the inside of the hind femur against the forewings, whereas bush-crickets stridulate by rubbing the forewings over each other. The yellow spots and line behind the head distinguish this from other bush crickets in the UK. The Roesel's Bush Cricket was once confined to coastal areas but is now spreading and more widespread.

Green Shield Bug (Palomena prasina)

Another bug we found was this little shield bug. I wasn't sure what it was at first but reference to the Photographic Guide to Shieldbugs and Squashbugs, by Martin Evans and Roger Edmondson showed it was final instar larva. Green shiled bugs are also known as stink bugs for obvious reasons.

No comments: