Can't help you with the "flapper", but I've used these things with VERY good results, AND one can trap bugs on the fly, or against the canvas without splatting blood on the canvas:

This is only ONE example, there are many types and brands:
http://www.amazon.co.uk/FlyCatcher-Electronic-Wasp-Mosquito-Killer/dp/B000ZNYG3Y
m2cw� Malcolm

>________________________________
>From: John Rodgers <inua@CHARTER.NET>
>
>an injection molded plastic two-flap pistol-grip fly
>swatter. There were two flaps mounted on a barrel, which in turn was
>attached to a pistol grip handle. 
>