Zappers of whatever sort, do little good. They bring insects to your garden and they kill more good guys than bad.

And that's according to several university-based trials.

As Jean stated these things, contrary to what the ads try to tell you, do little to control those insect pests that you want to control but they do kill large numbers of the beneficial insects.

I agree with the last two responses. If you are looking to be rid of Mosquitoes, the zapper will do little good as they are attracted to smell rather than light. The zapper will probably kill off more good or harmless insects than bad.