I'm wondering if anybody can tell me what kind of bug this is? It is incredibly loud and sounds exactly like a model airplane engine.

The only sound recording instrument I have is my camera, so I shot a movie of it... sort of. To minimize file size, I left the lens cap on, then transcoded the *.mov output into flash while doubling the audio output level. You will have to listen carefully to pick out the insect sound from the ambient noise.

It goes

tok.............tok.............tok..........tok........tok......tok.....tok....tok...tok..tok.toktoktoktoktoktoktoktoktoktoktoktok

ending up in a sustained high whine that continues for about 40 seconds, then goes quiet. In another minute or so it starts up again.

It is incredibly loud. The one I recorded here was probably 200--300 meters away. One landed on my deck and I couldn't hear the television even with the windows closed. I tried to photograph it but it flew away just as I got the camera ready. It was a flying beetle, about two and a half inches long. The volume is fully equivalent to a model airplane engine, and the first time I heard it I was convinced that that was what it was.

Take a listen...

tanstaafl.