Experimenting with CO2 as a pest control strategy

[camille1585]

I’ve read about CO2 being used to kill pests in terrariums, but haven’t come across much info on using this technique on individual plants, or which insects it works on, other than reading that spidermites are unkillable this way.

I’ve been dealing with mealybugs on my orchids since 2008. Most of the time they are under control, but during the nearly yearlong period of neglect my collection got, I’ll let you imagine the situation with them... I’ve thrown out many of the plants that are in bad shape, but some are favorites that I’d like to save. Pesticides never got them all in the past, so I want to try other methods to deal with these insects once and for all. CO2 gassing being my current experiment.

I brought one infested Phal to work yesterday, since we have CO2 cylinders in the labs. I placed the plant in a bag, removing as much air as possible, then filled it with CO2 and tied it shut. I then put it in my greenhouse compartment (where I grow plants for my research) hoping that the warm temperature in there (26C) would increase the insects metabolic rate (and so the amount of CO2 they breath in). I left it like that for 2 hours, and it seems that the majority of the mealies have died! So today I’ll be repeating the treatment (I’ll do 4 hours this time), and I’ve brought a few more infested orchids...

I plan to do repeat the treatment every 3-4 days for 2 weeks (to be sure that I got them all), and leave the plants in the warm and humid greenhouse to recover, before taking them home again, and then leave them in quarantine for another 3-4 weeks. I’m hoping that the CO2 will lead to a nice growth spurt as well, the plants need it.

I’ll post my progess in this thread, in case some of you are interested in the final outcome!