Giant Emperor Moth

[CDDI]

Hello all lepidopterists (always wanted an excuse to use that title) I need some help on how to construct a moth trap. Most years I come across one or two of the huge caterpillars that will emerge in April as Europe's biggest moth, the Giant Emperor or Peacock (saturna pyri).  The garden clearly attracts them, probably because there are plenty of fruit trees which is first menu-choice for the caterpillars. But the frustrating thing is that although I've kept a lookout I've never been lucky enough to see the monster moth itself.  Before spring I would like to set up a trap which allows viewing and then release without damage. (it should also be impervious to beech marten attack!).  Would greatly welcome any input on design, size etc.  Maybe forum members in more southerly climes will already be familiar with the Giant Emperor which I think is less common as you go north. It's completely absent in the UK. Thanks to everyone for making the forum such fun. Derek