Is it my imagination or ..... ?

[Pattock]

I'm old enough to remember signing the poisons register to get neat nicotine to treat my first collection.

I'm told that boiling cigarette ends in water and spraying it has some effect .... but inhaling the spray fumes is a different matter.

Nicotine also absorbs very efficiently through the skin. Enough to have killed both professionals using commercial sprays and amateurs using cigarette teas. Noddy suit would be advisable.

[Pattock]

I wonder what CO2 levels would be needed to have an impact on pests without harming plants? Whether this would be effective or not is going to depend a lot on how air tight you could make the treatment space. I also imagine you'd need some sort of smoke bomb treatment for the greenhouse at the same time to ensure you have eradicated it completely.

Most of the studies have been done with very high levels of CO2 for many hours on bedbugs. I have no idea if the plant would notice with its stomata shut. I wouldn't be surprised if there were some adverse effect. What happens at the roots?

[Herts Mike]

I only had the Big Ears suit. Would that work?

[Paul in Essex]

I used to wear a Mr Plod suit on a regular basis. Not sure that would have helped.

[el48tel]

An interesting idea to drown/suffocate them in nitrogen, but the practicality outside a laboratory environment, I find mind-boggling.
Will Linde supply cylinders to non-laboratory customers? I think not.
How will I make my GH completely airtight? I think impossible, if not, impracticable.
To calculate the amount of cylinders required is straightforward, but the cost of the project is likely to be disproportionate to the benefits.
What is the lowest limit of the partial pressure of nitrogen required to exterminate the beasts? That is an unknown, and relevant since we need to maintain it, again for another unknown, that of the time to exterminate the beasts. And to displace the existing atmosphere, and keep it displaced, without it ingressing again during the displacement is something which again is a practical problem, having all kinds of issues relating to diffusion of the gases.
Then we come to the Risk Assessment, Methods Statement and the like. Getting this wrong, could result in a visit to one's loved ones from the Geheimstatzpolitzei aka the Health and Safety Executive.
I think .... Pattock .... a non-starter.

Doing an entire greenhouse would be wasteful and difficult to ensure that the oxygen is all purged. It is not the partial pressure of nitrogen that is decisive but the absence of oxygen.

https://www.solentplastics.co.uk/27-5-l ... ng-bucket/

https://www.adamsgas.co.uk/product-cate ... food-wine/

There will always be idiots.
https://www.thedrinksbusiness.com/2021/ ... -accident/

I would not recommend this experiment to someone without experience in handling compressed gas and other asphyxiation hazards and silicone sealant.
https://www.youtube.com/watch?v=lGY2HaXd2IU

Helium would probably asphyxiate them faster but is also more difficult to contain and more expensive.

You would need to ensure the temperatures remained high, both for the comfort of the plants and so the bugs remain active and have a higher oxygen demand.

My only concern would be that the bugs might obtain some oxygen from the plant juices they imbibe. Or they are so lazy they don't use much oxygen. Otherwise, bedbugs die in a few hours.

Unfortunately, I have no pests at the moment.

You have re-enforced my points exactly

[el48tel]

I'm old enough to remember signing the poisons register to get neat nicotine to treat my first collection.

I'm told that boiling cigarette ends in water and spraying it has some effect .... but inhaling the spray fumes is a different matter.

Nicotine also absorbs very efficiently through the skin. Enough to have killed both professionals using commercial sprays and amateurs using cigarette teas. Noddy suit would be advisable.

Exactly my point!

[habanerocat]

I wonder how long a cactus could survive in a pure nitrogen atmosphere?

https://academic.oup.com/jee/article/109/3/1310/2648749

Wouldn't that be similar to trying to drown them? And I think it's been proved that that doesn't work.
Depends on the duration again I suppose.

The difference is that their waxy coat keeps the water from entering the spiracles so they can still exchange gases. In this case there would be no oxygen for them to breathe at all.

Informative rating.....

[SimonT]

Cold treatment seems to be a good option as long as the plants with survive this. This might even kill eggs as well.
In the UK I've never seem a mealy bug on outside plants- purely an indoor problem.
Using cold is safe, saves money and is eco friendly. Perfect, just I'm not sure of the dose of cold to use...

[JonNo]

The "bleach bath" method Ali baba kindly suggested to me back in August (thread title "Dilemma") seems to have worked on the Echinocereus Rigidissimus Rubispinus I tried it on. There is no sign at all now of Mealy, which I had struggled to eradicate for an age, and so far as I can tell the plant is still alive... The only side effect I have noted so far is that the red spines are now a straw colour. It is a method I don't think I'd risk on every plant, and it would be impractical for an entire collection, but for the odd plant I think it is an option. Thanks Ali Baba.

[ralphrmartin]

If you wore an Andy Pandy suit, maybe Little Weed would help you...