"reduce the entrance to one, easily defendable, bee-way" --  the same hornets work in a bit of a different way here.   Yes, a hive can get penetrated but that is the end stages of colony weakening.  What happens before that is ten or twenty hornets  remove bees returning to the hive (but not when they are leaving).  This goes on in daylight hours day after day.  When sufficient bees have been removed then the hornets enter the colony.

Whilst it is too labor intensive to be serious it is very pleasing to play badminton with the hornets.  You have to hit them very hard  though but it does take them out of the cycle.  Obviously not a practical solution for anything other than relieving frustration.

A trap  that holds the hornets is really the only way.

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm