How to get rid of orchid snails?

[JanS]

Greetings!
I've been in a battle with "orchid snails" (also called bush snails) for quite some time and have done quite a bit of research on them. I've followed various web discussions and suggestions and thought members of this forum would appreciate a summary...as well as for me to pose the on-going question - How to best get rid of the bastards?

Orchid snails are the very small snails that hide in the potting medium during the day, crawl out at night and eat the new root tips of many orchid species. Other bigger snails and slugs seem to be much more easily controlled with readily available baits, but these little guys do not seem to be attracted to them. Here's an excellent summary scientific article showing photos and discussing the best tested treatments:

http://www.ctahr.hawaii.edu/oc/freepubs/pdf/MP-1.pdf

I was ready to buy the 25% metaldehyde "Slug-fest" liquid and get rid of my problem once and for all - only to find out it is unavailable - the EPA banned it a few months ago. Note that the research in the above article states that metaldehyde-containing baits are NOT effective! Lilly-Miller still sells a spray (made for them by the Slug-fest company) but at much lower concentrations. I guess I'll give it a try (it appears soaking the metaldehyde into the bark to create actual contact with the snails is the only way to go).

One other note: Some years ago there was research claiming that caffeine in 3-5% concentration will kill the snails - apparently by giving them a heart attack. I've seen a lot of discussion about how to use this method, or using coffee grounds, etc. Short of purchasing pure powdered caffeine from a chemical supply, the only way to even get close to a 3-5% solution is to buy caffeine tablets at a drug store, grind them up and dissolve them in the appropriate amount of water. I did just that but there are complications: First, the tablets consist of mostly chalky filler, so for 50 tablets' worth you end up with less than a liter of liquid (to get close to 4%) and a huge amount of chalky mud, which I settled out and just recovered the liquid which I ran through a number of infested orchid pots. At $10 or so for a 50 pill bottle, this procedure is not very economical for even a moderate number of plants. Results? I must say it did seem to help for a while but (at least with a single treatment) the snails were back in a month or so - either not all died and/or the caffeine does nothing to the eggs. Hope this info helps for anyone contemplaiting the "Heart Attack Remedy".

So with this said - does anyone have experience with a truly effective treatment for these extremely destructive pests? What do large orchid growers do?

Thanks!