Experimenting with CO2 as a pest control strategy

[naoki]

I think that some people use dry ice because they don't have CO2 tank and regulator (but you do).

For mealy, imidacloprid-based one (e.g. Confidor) always worked for me. Even though it is systemic, I do need to apply it a couple times. Insect-hormone based insecticide (e.g. Enstar II) seems to be pretty promising and not so scary for human. It is probably difficult to develop resistance for this (it is important to completely eradicate).

For plants I use for research, I have suffocated bugs (aphids) by submersing the plant under water for overnight or longer. Plants don't seem to mind suffocation too much. Note that respiration of plant cells increase significantly with the temperature.

I haven't had bush snail issues, but it seems like a real 'pest'.

[bil]

Good point about the buoyancy. An individual plant can be put under a hood, so that the air is displaced out by the helium downwards.

---------- Post added at 02:13 PM ---------- Previous post was at 02:11 PM ----------

Originally Posted by naoki

I think that some people use dry ice because they don't have CO2 tank and regulator (but you do).

For mealy, imidacloprid-based one (e.g. Confidor) always worked for me. Even though it is systemic, I do need to apply it a couple times. Insect-hormone based insecticide (e.g. Enstar II) seems to be pretty promising and not so scary for human. It is probably difficult to develop resistance for this (it is important to completely eradicate).

For plants I use for research, I have suffocated bugs (aphids) by submersing the plant under water for overnight or longer. Plants don't seem to mind suffocation too much. Note that respiration of plant cells increase significantly with the temperature.

I haven't had bush snail issues, but it seems like a real 'pest'.

Drowning them? Interesting! Would it be an idea to add a tiny drop (REALLY TINY) of washing up liquid to the water? That would allow the water to penetrate the spiracles of the bugs and drown them quicker?

[Ordphien]

Originally Posted by camille1585

In grocery stores????? Wow. Here I order it from lab supply companies to use to send frozen leaf samples across Europe. But beats me why someone would need dry ice for everyday use, considering that it is something to use with caution...

Oh you know. Witches cauldrons need to bubble and sometimes our morning coffee needs a special kick. Lol.

I'm not entirely sure why it's sold in grocery stores here. We use it alot to show cool science tricks to kids. And i use it alot in my garden.

[NYCorchidman]

Originally Posted by Ordphien

Here they sell it in grocery stores. Normally up front.

It depends. One normally does the trick. But I usually do two to be safe.
The spider mites took 6 treatments! I've been battling those guys for two years on that stupid tree.

How did you do that with dry ice??
Can you explain in more detail?
Apparently plants were not harmed by the cold.
I had no idea dry ice was sold at grocery stores. don't think I've seen it here. I'll have to look.

[Ordphien]

Originally Posted by NYCorchidman

How did you do that with dry ice??
Can you explain in more detail?
Apparently plants were not harmed by the cold.
I had no idea dry ice was sold at grocery stores. don't think I've seen it here. I'll have to look.

I double bag the plant in some garbage bags.
Then I set a dish of hot water in a grocery bag which I cut a few small holes into. That gets placed in the garbage bag next to the plant.
I make sure the container of water is not touching the plant as the container will get cold.

Dry ice is sold by the pound at my store. $3 a pound specifically. So I use about a pound per treatment.

I then drop the dry ice into the water and quickly tie the grocery bag loosely.
The.... is it vapour? The vapour isn't really that cold, and the hot water helps keep it warmer. The grocery bag is so no cold water will splash on the plant. .
After tying the grocery bag I thoroughly knot the two grocery bags and watch it inflate.
I tend to do it before bed and let it sit over night.

One other way I do it is to stick tubing in in the cap of a large bottle. Put the plants in a closed container, and fill the bottle with dry ice and hot water.
The bottle method tends to need refilling a few times.

[Ordphien]

I'd rather use a tank and regulator if I'm honest.

[DavidCampen]

Camille, can you give us an update on your experiment?

[camille1585]

Well so far it seem that the mealies are just about gone. I did 2 treatments a few days apart, and in a few days will do it again to catch any survivors. The Phals took it quite well and are putting out new roots now. The 2 Dens are looking fine, though the new growth of my Den tetragonum didn't like the CO2 and died off. Luckily I see a new one starting already. That plant looks pest free, so I wont treat it again so that I can preserve that new growth.

[DavidCampen]

Originally Posted by camille1585

Well so far it seem that the mealies are just about gone. I did 2 treatments a few days apart, and in a few days will do it again to catch any survivors. The Phals took it quite well and are putting out new roots now. The 2 Dens are looking fine, though the new growth of my Den tetragonum didn't like the CO2 and died off. Luckily I see a new one starting already. That plant looks pest free, so I wont treat it again so that I can preserve that new growth.

How long do you keep the plants in the CO2 chamber?

[camille1585]

The first time I left them in the bag only a couple hours, and the second time was about 8 hours because I was busy and forgot about them all day... It's not pure CO2 though. I removed as much air as possible from the bag before filling with CO2, but I didn't dare leave the CO2 on on to flush out the remaining air. For some twisted reason, the CO2 tap is located in a closet sized room that has limited ventilation, rather than being in one of the labs which are extremely well ventilated. So I didn't feel like killing myself along the bugs...