actually liqure works well for controlling some pests i duno about vodka but beer lol i used strawberry shnaps this summer killed the pests on my plants n a whole bunch of wasps i dont know if it would work for those flies but its a glass trap that hangs on a metal pole u stick in the dirt the insects fly in drink the sweet sugary liqure cant get out n they drown n die worked awsome for me pretty fast too n u dont gotta spray ur plant with anything just an idea give it a shot if u want lol peace