Using Carbon Dioxide (Dry Ice) For Pests
 

I have read in this forum that dry ice can be used in a terrarium to control pests. I am very nervous to do this. I found these instructions from a dry ice company and wanted to run it by other orchid folks to see what you guys think: Cleaning Terrariums - Airgas(R)

Is letting the CO2 sit for three hours enough?

I'm also not sure how much to use for a small enclosure 12x10x18 and a larger enclosure 24x20x14 (20 gallons).

Thanks!!

It can definitely work, but I'm not certain how long various pests can hold their breath. Plus you'll need to know the life cycle of the specific pest, since it will probably have no effect upon eggs and will need to re-treat to get any new ones that hatch after the initial treatment. As far as how much to use, I used to cut up old underground gasoline storage tanks with an oxyacetylene torch, and we used 20lb per 1000 gal of tank volume to displace the air and prevent us from blowing ourselves up.

One of the things that the article mentions is removing the plants and other (desired) residents. However, bugs, slugs, etc. tend to hide on the plants. So the treatment won't get those unwanted residents. You certainly would not want to expose the plants the cold, and they probably would not be happy with oxygen deprivation. What are you removing the pests from?

I'm not sure why the removal of the plants is suggested, as it does indeed defeat at least some of the purpose of the treatment. The cold could certainly be an issue, but I've left plants overnight completely submerged in water without harm, so I doubt that oxygen deprivation would be an issue in the short term.

Dry ice is very cold, so even if the CO2 atmosphere didn't hurt the plants, that's a big issue - you'd have to somehow keep the dry ice far enough from the plants that the CO2 gas would have a chance to warm up before hitting the plants (maybe include a heat source).

For certain. Fortunately CO2 is considerably heavier than air, so suspending the dry ice above the container will allow the gas to drop into the container.

Thanks for your responses. I was at an orchid show, and I was showing Andy (of Andy's orchids) my setup and he suggested that I might have bugs or some sort in the terrarium. He suggested I CO2 bomb the terrarium using dry ice. I've enclosed the photos in this reply. You can see spots on the middle of my tuberolabium kotoense and there is some discoloration on the dendrobium abberans. I figured the dendrobium is deciduous, but Andy said it is not. I have lost a few other leaves due to this discoloration.

I'm also facing mealybugs on my non-terrarium plants which I have treated on several of my plants, but I suspect I found a baby one today. I have throughly treated these plants and sterilized the growing area. I was going to put them in a large storage bin to treat them with the CO2.

The dry ice itself is only in the enclosure for five minutes. Hot water is added to help counteract the very cold temperatures (to what degree this helps, I'm not sure). After the enclosure is filled with the C02, it has you pour some more of the gas into the enclosure and then seal it up. Essentially, the dry ice is only there for five minutes. I'm guessing that helps with the temperature issues.

hey I dont know if you re still active here in the forum. Just wondering if this CO2 bombing experiment was a success of not.