Last week I was on a canal boat holiday. The highlight of the whole trip (in my mind) was this beetle, Agapanthia villosoviridescens, which was photographed on Claire's finger. It wasn't so much that it is pretty (though it evidently is), it was that when handled it made a very audible squeak.
Closer observation showed that when it squeaked it also moved its pronotum relative to its elytra, suggesting that it produces the sound by flexing the hinge between pronotum and elytra.
I felt sure that this behaviour would have been observed and reported before, so was surprised when I got home yesterday and looked it up to find no reports. It could simply be that I haven't looked in the right places, but I've tried every possible web search that I can think of and have found nothing. In addition, Andrew Duff's articles on longhorn beetles in British Wildlife fail to make any mention. It seems worthy of a blog simply to report the behaviour.
According to the NBN Gateway, A. villosoviridescens has an odd distribution in the UK, deing restricted to the mid- and eastern-England, but absent from the extreme south or south east. Apparently it used to be considered very rare. It's larvae feed in the stem tissues of thistles and umbellifers.