A major problem is . .
. . they are particularly effective against beneficial insects, as a survey of the carcases will show, and not particularly effective against biting insects. I trashed mine many yeas ago for precisely that reason - mosquitos wouldn't go near it even if you put it in the same room with one.
I haven't seen one here in Southern California for many years, so I wouldn't be surprised if they're banned here also. Fortunately I don't really have much of a mosquito problem these days, or I'd be tempted by one of those Mosquito Magnets.
