6/26/12 I responded to a Post here on the Fotum concerning these Snails.At that time they were a real problem here and I was having quite a fight in order to keep them away from my Orchids. YES they will devour a whole plant in one night. I am happy to report that the Govt. started a drive to get rid of them by offering to pay by the pound to have people collect and bring them in, and then they would burn them. What I did, was, stopped watering in the evening, and if it rained before my bedtime, I would go out all gloved-up, with a flashlight and a pail with Chlorox, pick them up and drop them in the pail. The Chlorox kills them and their eggs. You must NOT crush them. That only releases thousand of eggs into the ground waiting to hatch. I also had to use liquid Metaldehyde and water the perimiter of my property to stop them from coming from nextdoor.
I am happy to say I do not see them in my garden anymore, and the Dept of Agriculture has recently announced that a number of predators ie. Egrets and lizards had also helped. They have discontinued their bounty.
I saw the that article on MSn today, and I truly pray that those of you in S. Florida will be diligent so that they do not get to your 'chids.