The Terminator...

[JonNo]

A few weeks ago, one of my plants was behaving strangely (in fact I posted a question about it on here). Being a quite densely spined Echinocereus Rigidissimus Rubispinus, I couldn't tell if there was anything lurking, crawling, so I sprayed it liberally with Bug Clear Ultra (acetamiprid). A fortnight later, I sprayed it again, and then a week after that I sprayed it with SB Plant Invigorator just for good measure.

A week after that, with the poor plant still looking out of sorts, and having started to wage war against crawlers elsewhere, I decided to use this plant as the flagship and give it the full treatment. I took it out of its pot, carefully removed what compost I could, then soaked the rootball several times in warm, soapy water. Then I "power washed" the entire plant with an oral irrigator before rinsing everything in clean water. As best I could tell it appeared absolutely clean. I let it sit a while, then sprayed everything including the rootball with SB Plant Invigorator. I left it to dry overnight, then the next day re-potted it in a new pot with fresh compost, and set it away from any other plants..

A week on from that, I "power washed" the body of the plant again with the oral irrigator, then, when it had dried, brought out my final weapon and sprayed the whole plant thoroughly with methylated spirits. I returned it to splendid isolation and let it be...

A week on from that, today, I picked up the plant to inspect it and, sitting on top of it was - a Mealy Bug... True, it was in a bad way and virtually motionless, but as I reached for my needle and speared it through the chest it looked at me with its one remaining eye, which was glowing red, and said - "I'll be back"...

The plant is almost certainly dead now but at least I have the satisfaction of knowing it is free of crawlers - or do I? These damned things seem virtually indestructible!

[Tina]

Good story , poor plant.
I still believe they 'TELEPORT' bo other explanation

[Chris L]

The trouble is always the eggs that we cannot see.

As the life cycle is so long once you see them they are more or less certain to have laid eggs already.

I suspect, given that you've only a small collection, the only way you might get rid of them is to de-pot, clean with meths, repot with Diatomaceous Earth* mixed in with the compost and a bit sprinkled on the compost surface. Then it will still be a case of picking of any bugs that you see ASAP as an ongoing battle. It would not surprise me one bit if there are mealies within the compost that we buy.

The DE works as a cutting agent and will kill any bugs that crawl through it trying to get from plant to plant.

I have used DE on my own collection - as mentioned before it was on the plants from September 2019 to May 2020 but in the GH. It has had a drastic affect on how many mealies I've seen this year, but of course the weather has been a bit rubbish lately so that may also have knocked them back.

I usually find that August and September are the worst months for finding them and I am more than likely planning on covering the plants with DE over winter again, but starting much earlier - maybe in August.

You'll also need to thoroughly clean the window sill, frame, seals and glass and any and all trays, plus all the labels and pots.

I don't think there is anything on the market now that will kill them outright because there are always eggs on the go. All you can do is control the population to try and reduce it to as small a number as possible.

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* Mask essential.....

[JonNo]

The trouble is always the eggs that we cannot see.

As the life cycle is so long once you see them they are more or less certain to have laid eggs already.

I suspect, given that you've only a small collection, the only way you might get rid of them is to de-pot, clean with meths, repot with Diatomaceous Earth* mixed in with the compost and a bit sprinkled on the compost surface. Then it will still be a case of picking of any bugs that you see ASAP as an ongoing battle. It would not surprise me one bit if there are mealies within the compost that we buy.

The DE works as a cutting agent and will kill any bugs that crawl through it trying to get from plant to plant.

I have used DE on my own collection - as mentioned before it was on the plants from September 2019 to May 2020 but in the GH. It has had a drastic affect on how many mealies I've seen this year, but of course the weather has been a bit rubbish lately so that may also have knocked them back.

I usually find that August and September are the worst months for finding them and I am more than likely planning on covering the plants with DE over winter again, but starting much earlier - maybe in August.

You'll also need to thoroughly clean the window sill, frame, seals and glass and any and all trays, plus all the labels and pots.

I don't think there is anything on the market now that will kill them outright because there are always eggs on the go. All you can do is control the population to try and reduce it to as small a number as possible.

.
.
* Mask essential.....

Thanks Chris!

I'm currently just over half way through re-potting, it is surprisingly labour intensive and time consuming if done with care... DE sounds an excellent idea, but given that my plants live in pots on trays in my kitchen and lounge I'm nervous about using it.

So, can meths just be poured onto the surface of the compost (or indeed onto the top dressing with a view to it running through to the compost and thus "cleansing" both) without doing any harm, i.e. damaging the plants? I'm wondering if that might be worth adding to my regime...

[habanerocat]

The trouble is always the eggs that we cannot see.

As the life cycle is so long once you see them they are more or less certain to have laid eggs already.

I suspect, given that you've only a small collection, the only way you might get rid of them is to de-pot, clean with meths, repot with Diatomaceous Earth* mixed in with the compost and a bit sprinkled on the compost surface. Then it will still be a case of picking of any bugs that you see ASAP as an ongoing battle. It would not surprise me one bit if there are mealies within the compost that we buy.

The DE works as a cutting agent and will kill any bugs that crawl through it trying to get from plant to plant.

I have used DE on my own collection - as mentioned before it was on the plants from September 2019 to May 2020 but in the GH. It has had a drastic affect on how many mealies I've seen this year, but of course the weather has been a bit rubbish lately so that may also have knocked them back.

I usually find that August and September are the worst months for finding them and I am more than likely planning on covering the plants with DE over winter again, but starting much earlier - maybe in August.

You'll also need to thoroughly clean the window sill, frame, seals and glass and any and all trays, plus all the labels and pots.

I don't think there is anything on the market now that will kill them outright because there are always eggs on the go. All you can do is control the population to try and reduce it to as small a number as possible.

.
.
* Mask essential.....

So, can meths just be poured onto the surface of the compost (or indeed onto the top dressing with a view to it running through to the compost and thus "cleansing" both) without doing any harm, i.e. damaging the plants? I'm wondering if that might be worth adding to my regime...

I wouldn't like to try that. Generally people just advice dipping the clean roots in it for a few minutes, then washing it off. If you want to use something ongoing try SB Plant Invigorator or make up your own Neem Oil solution as posted in some threads here.

https://forum.bcss.org.uk/viewtopic.php?f=1&t=170190

[FredG]

I thought Neem Oil was banned as a pesticide in the UK.

Neem oil exposure may cause abortion or lead to infertility, and it may cause liver damage in children. Pesticides containing neem oil (Azadirachtin) are banned in the UK.9 Sep 2016

[Tina]

Neem Oil was banned as a pesticide in the UK

ha ha but you can buy it & put on childrens heads for bugs, logic there somewhere. I got mine from ebay.
Using meths if you have had a lot of damage to the skin of the plant it tends to leave marks .

[anders]

So, can meths just be poured onto the surface of the compost (or indeed onto the top dressing with a view to it running through to the compost and thus "cleansing" both) without doing any harm, i.e. damaging the plants?

No. I have tried, but it damages the roots. Cacti with thick roots and cold-hardy types are especially sensitive.

[JonNo]

So, can meths just be poured onto the surface of the compost (or indeed onto the top dressing with a view to it running through to the compost and thus "cleansing" both) without doing any harm, i.e. damaging the plants?

No. I have tried, but it damages the roots. Cacti with thick roots and cold-hardy types are especially sensitive.

Thanks anders (and everyone else), that is very useful information and much appreciated.

[rodsmith]

I use meths as a drip to kill mealies on contact. I have used it on my wife's Aeonim Zwartkop which had a major infestation of root mealies. I de-potted it and soaked the roots in meths after washing off all the soil, then washed well in cold water. It worked but for weeks afterwards the smell of meths was in the conservatory (where the plant is kept in winter).