It's a 2-pronged approach, Bti water(mosquito dunks are the same as Gnatrol and much cheaper)but does not kill the juveniles/adults...hence pest strips. You can't just go to any garden center and buy nematodes: http://wiki.bugwood.org/Steinernema_spp.
To all: Those mosquito dunks can be saved and re-used for up to a month.
