Welcome to OrchidsForum.com. We are a friendly online community for Orchid Growers all over the world. If you haven't joined yet we invite you to register and join our community. Hope to see you on our forums!

Snail/slug control - The never ending battle

Discussion in 'Issues, Disease and Pests' started by RustyExotics, Jun 5, 2018.

  1. RustyExotics

    RustyExotics Nicholas - It's a terrestrial thing

    Messages:
    410
    Likes Received:
    275
    Location:
    Georgia
    Hello everyone,

    I'm starting this post because I was curious as to how other people tried to control the snails and slugs that love eating new growths and flowers so dang much... I've grown my Stanhopea type orchids outside for the past 3 years or so. They love it outside, so I don't want to bring them in, but it's gotten to the point that I can't even count the number of flowers and new growths that I've lost to snails and slugs.

    I have tried using several "snail/slug pellets" and even dig a huge repotting and cleaning this year where I repotted the orchids, cleaned and disinfected their pots, soaked the orchids in a dilute Hydrogen peroxide solution, and treated them for snails again. And they're back...

    Does anyone have any tips and tricks to controlling them? I was mortified to figure out that the snails found it back into the pots, so I really need some outside help with them.

    Thank you all so much.
     
  2. Ray

    Ray Orchid Iconoclast Supporting Member

    Messages:
    1,645
    Likes Received:
    465
    Location:
    Oak Island NC
    The first thing to think about is a mechanical barrier. They must "walk" into the container to get to the plant, so if you can block that pathway, they simply cannot do damage. There are many ways to accomplish that.

    Copper foil (often sold in a self-adhesive tape form) is the old classic, wrapped around bench legs, or whatever stand or platform the plants are sitting on. A salt perimeter is also very effective, but must be replaced when it gets wet. There is a gel in a tube called "Tree Tanglefoot" that is also quite effective.

    As far as eliminating those that have already gotten to the plants, a metaldehyde bait is the most effective. Marni turned me on to Deadline MPs, but it is quite toxic to mammals, so is best used where access can be restricted.
     
  3. RustyExotics

    RustyExotics Nicholas - It's a terrestrial thing

    Messages:
    410
    Likes Received:
    275
    Location:
    Georgia
    They're actually all hanging in trees which is why I've never done the physical barriers. I do use deadline MP's, but they snails just ignore them... They seem to like the roots and flowers of my plants more... Is there any other brand you might recommend besides deadline?
     
    Last edited: Jun 5, 2018
  4. carl

    carl Active Member

    Messages:
    450
    Likes Received:
    160
    Location:
    Sooutheastern Pencilvania
    Use the "Beer Trick" - in the evening, go out to the plants with a flashlight, hammer, and a bottle of beer. Using the flashlight, when you find a slug (or snail), you slug it with the hammer, then have a slug of beer.

    You won't get them all, but after a little while, you won't mind.
     
  5. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
    I stopped using the Deadline MP. I use metaldehyde 7% granules to spread under the benches. I drench with Sevin/carbaryl and that is quite effective against slugs and snails. It doesn't really seem to do much to the bush snails. There is also Slugfest, a concentrated liquid metaldehyde. You need to let your plants dry after treating with it, which doesn't work out so well with many of the plants I grow.
    I don't know about snails, but slugs can produce a strand and do a controlled drop from above. It is pretty amazing to see.
     
    RustyExotics likes this.
  6. RustyExotics

    RustyExotics Nicholas - It's a terrestrial thing

    Messages:
    410
    Likes Received:
    275
    Location:
    Georgia
    Yeah, I'm not sure how well the whole "drying out" thing would work for my plants, but I think I'm willing to try it at this point. Do you know how long they need to stay dry for? . I'll give the sevin a go, too.

    Thank you all for the help!
     
  7. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
    Nicholas, I don't have an answer to "how long". The Sevin doesn't need a drying out period. I water heavily in the morning and then treat in the ate afternoon or early evening when it is cool. That way the critters are brought out from hiding places and have all night to cruise around. The first time I used the Sevin WP I added a spreader sticker. Maybe I used too much, but it took forever for the residue to disappear. I now use a liquid but never used the spreader sticker again. Good luck!
     
  8. RustyExotics

    RustyExotics Nicholas - It's a terrestrial thing

    Messages:
    410
    Likes Received:
    275
    Location:
    Georgia
    Thank you all! I need all the help and luck I can get...
     
  9. Chuck-NH

    Chuck-NH Well-Known Member

    Messages:
    1,943
    Likes Received:
    1,844
    Location:
    New Hampshire, USA
    Hi, I have used Slug-Fest and know a couple commercial growers as well who do...because it does work on the snails. There is the increased hazard potential when spraying, so not for the casual user as metaldehyde is quite toxic

    Marni - I don’t know where you got the instructions for keeping the plants dry, unless an older formula? The intent is to spray after watering (or rain for outdoor crops) when things are wet and preferably in the evening so the critters are most active.

    The following is from the manufacturer’s promotional literature

    Slug Fest® All Weather Formula
    Slug-Fest All Weather Formula contains 25% metaldehyde in a liquid formulation. This is the only liquid sprayable slug and snail control in the world. Slug-Fest is highly efficacious as a slug and snail eradicant. This product is best applied right after it has rained so you know the slugs or snails are active.
     
  10. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
    Chuck, I water heavily BEFORE applying and let the plants dry AFTER applying SlugFest.
     
  11. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
    I just did a bit of investigating about metaldehydes effect on slugs and snails and it seems that they die from dehydration is another myth. So there seems to be no need to dry the plants after treating.
     
  12. naoki

    naoki Well-Known Member

    Messages:
    2,462
    Likes Received:
    1,169
    Location:
    Fairbanks, Alaska
    I was interested in counter-measures against bush snails, so I read a little bit about different methods. I thought that the toxicity of Metaldehyde seems to be reasonable. The warning seems to come from pets eating pellets. But according to Wikipedia (here, and the reference here), the toxicity level is similar to acetaldehyde, which is a fairly "natural" molecule. There doesn't seem to be too much mutagenic effects (long term effect), so the danger is acute toxicity if someone eat it. Also, MH breaks down rapidly in soil and in water, so it doesn't accumulate. I probably shouldn't say that it is safe (especially after seeing people lacking common sense since Nov. 2016), but I have been considering that it is relatively mild.

    I think that this (whether you need to keep them dry after application of MH) doesn't seem to be completely set. For example, Hollingsworth (2003, p.121) mentioned that snails recover better from MH poisoning under moist environment (citing a couple papers). When snails are exposed to MH, they excrete bubbly mucus. Some people think that this causes the dehydration and death. Then, it is more effective to suppress the subsequent watering after application.

    More recently, I was reading a book, Molluscs as Crop Pests by G. M. Barker (ed.)(amazon link), and they mention that the exact mechanism of how MH kills snails is not known yet. They also mentioned that there appear to be other mechanisms than dehydration, and MH can work under moist environment.

    So recently, I'm not keeping them dry after application. Similar to Marni, I noticed that some plants become unhappy if I dry it after MH application. But if I don't do extreme driness, I don't see any Phytotoxicity even if I overdose. Several papers also reported no phytotoxicity (e.g., here), which is a good thing.

    Ref to Hollingsworth's paper.
    Hollingsworth, R.G. and Armstrong, J.W., 2003. Effectiveness of products containing metaldehyde, copper or extracts of yucca or neem for control of Zonitoides arboreus (Say), a snail pest of orchid roots in Hawaii. International journal of pest management, 49(2), pp.115-122.
     
    e-spice and RustyExotics like this.
  13. Chuck-NH

    Chuck-NH Well-Known Member

    Messages:
    1,943
    Likes Received:
    1,844
    Location:
    New Hampshire, USA
    Great information Naoki, The only crop I could find where watering was mentioned was grass: “reduce watering” of grass being grown for seed for two days. In Florida, the State used it to combat the Giant African Land Snails, so its likely that moisture in the ground was quite cyclical in a 24 hour period. The REI is 12 hours, so if you apply in the evening when moist and hold off watering until mid-morning the next day, that would seem to be enough contact time. I have seen one study where mortality was around 65% within 12 hours. I’ve only used it about twice per year without modifying my watering routine with no issues and great results...of note, the manufacturer does state that leaf tip burn has been reported in some “sensitive” orchids.

    I will have to look up the source (I think UFL), but I believe that Slug Fest was actually more effective that the old Measurol in field trials.

    Regarding toxicity, what I was referring was the opportunity for human exposure to 4% metaldehyde in a granular bait form vs a sprayed liquid metaldehyde in a closed up hobby greenhouse.
     
    e-spice and RustyExotics like this.
  14. RustyExotics

    RustyExotics Nicholas - It's a terrestrial thing

    Messages:
    410
    Likes Received:
    275
    Location:
    Georgia
    On the topic of Slug Fest: Do you know where I could buy some? I've been looking on Amazon and found nothing and googles in and found Orcle Slugfest, but wasn't sure if it was the same thing.
     
  15. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
    OrCal is the company. You can contact the company for distributors. Phone: 541-689-4413.
     
    RustyExotics likes this.
  16. Chuck-NH

    Chuck-NH Well-Known Member

    Messages:
    1,943
    Likes Received:
    1,844
    Location:
    New Hampshire, USA
    It is hard to find distributors...I think a place called something like Seed Ranch was one.
     
    RustyExotics likes this.
  17. Marni

    Marni Well-Known Member Staff Member Supporting Member

    Messages:
    13,163
    Likes Received:
    2,931
    Location:
    Santa Rosa, CA
  18. seidenfaden

    seidenfaden Well-Known Member

    Messages:
    350
    Likes Received:
    283
    To stop slugs or snails attacking the flowers on my plants I fasten cotton wool around the stems. Be careful when killing these pests, their relatives are to be found at their funeral.
     
  19. Alex Shepack

    Alex Shepack Active Member

    Messages:
    105
    Likes Received:
    151
    Dredging up this old thread:

    Does anyone have new recommendations for dealing with slugs and snails? I'm thinking to try Sevin. I've heard of some success from spraying caffeine, and metaldehyde of course. One of my biggest constraints is that the plants are all indoors, and I keep them in the same room as a bunch of frogs, so I'm hesitant about using the really heavy duty stuff.
    But - I'll consider anything at this point. The slugs are wreaking havoc and my nightly searches aren't doing the trick.
     
  20. Chuck-NH

    Chuck-NH Well-Known Member

    Messages:
    1,943
    Likes Received:
    1,844
    Location:
    New Hampshire, USA
    If you use metaldehyde granules, it shouldn’t be any problem unless they are in the the same tank as the frogs.
     
    Alex Shepack likes this.