I am not a senior member. However I have found that my white Dendrobium is particularly attractive to slugs and snails. I have isolated the plant inside now, and spread slug/snail bait around it's pot. The pests that go for the bait are killed, instead of killing my orchid...It is not nice..I have read that barriers can be used..such as sticking a copper barrier around a pot, or sharp pebbles/salt, or a sticky honey layer..I am sure if you Google this, more tips will come up too.
However physical removal of the pests, and not leaving the plant on the ground, may be your best security.