drenching root mealy bug

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mary44
Posts: 157
Joined: Sun Jun 07, 2015 10:44 pm

drenching root mealy bug

Postby mary44 » Sat Sep 09, 2017 7:35 pm

I was horrified to find a lot of root mealy bugs on some of the roots of my lithops this autumn as I started doing some potting up. I am pretty sure I know which pots the culprits arrived in, for once I did not pot up some lithops I purchased as the pots seemed ok on arrival. A cautionary tale.

Now I find the infestation has moved through most of my greenhouse and including a lot of 12 month old seedlings too :(

So I have removed all the soil and washed the roots as best I can of those pots and am in the process of going through the whole greenhouse drenching every pot with provado vineweavil killer the white emulsion that you dilute and pour into the soil rather than spray the plants. It is going to take some time and a lot of chemical but I cannot afford the time to wash the roots of every plant right now.

My question is, if I drench them presumably I will need to repeat this fairly often to kill any eggs hatching, and how do I know if it has worked? will the white bodies and signs remain once the pests are killed or will the evidence disappear? Has anyone done this before to advise me?

Also am I using the best chemical for the job? I have another chemical, I also have a bottle of Bug Clear Vine weevil killer which is a different chemical acetamiprid but says it does the same job. I have not used it before to know if it harms lithops. I am super cautious as I don't want to accidentally damage my plants.

The plants all look very well and do not seem bothered by their visitors. More my horror at finding so many..

Edited to say I see Alan recommends on the other thread to repeat in 3 to 4 weeks which I will do.

Limania
Posts: 85
Joined: Sun Jul 02, 2017 3:35 pm

Re: drenching root mealy bug

Postby Limania » Sun Sep 10, 2017 12:56 am

Drenching is an appropriate measure.
I never had the need of doing this more than one time, but this surely depends on the active substance. A as far as I know Provado contains Imidachloprid, which is a systemic poison, so maybe some eggs will survive, but not the slipping bugs.
By the way: I never washed the roots till now.

Allan1
Posts: 271
Joined: Fri Jan 23, 2015 7:24 pm

Re: drenching root mealy bug

Postby Allan1 » Mon Sep 11, 2017 6:17 am

Hi Mary, it is too late in the year to drench again. You would likely lose more lithops by drenching in October than from Root Mealy.
I would not use a chemical in my first watering next spring. If they were mine, I would let them wake up first then drench them twice --approximately 3 weeks apart. ( I am a belt and braces type person )
Allan
Orkney
Lithops,Cacti,Conophytums,Tylecodons,Sempervivums and Sedums

Limania
Posts: 85
Joined: Sun Jul 02, 2017 3:35 pm

Re: drenching root mealy bug

Postby Limania » Mon Sep 11, 2017 8:01 am

6 months with mealy bugs? Perhaps this would kill more Lithops than drenching.
In fact: Provado contains Imidachloprid - a systemic poison. So you'll nead no drenching! Pour as usual, but add Provado to the water - once. So if you really could not kill all bugs, you'll reduce them to a minimum.

Allan1
Posts: 271
Joined: Fri Jan 23, 2015 7:24 pm

Re: drenching root mealy bug

Postby Allan1 » Mon Sep 11, 2017 6:13 pm

Hi Limania, I based my reply on the facts that Mary had washed the roots of the worst and drenched everything. You your self said, you do not need to drench twice. I therefore estimated, that she would have very few Root mealy over the winter, if any.
Sorry if I gave the wrong impression.
Allan
Orkney
Lithops,Cacti,Conophytums,Tylecodons,Sempervivums and Sedums

Limania
Posts: 85
Joined: Sun Jul 02, 2017 3:35 pm

Re: drenching root mealy bug

Postby Limania » Mon Sep 11, 2017 6:32 pm

Hi Allan,

I think, it's not a "wrong impression" - more my "wrong comprehension"...
Sometimes I've to invest more energy in translating vocabulary than grasping the sense of the text .... :roll:

Perhaps washing the roots is beneficial, sometimes it seemed to me, that dead bugs fostered fungal diseases - because they opened the epidermis.

mary44
Posts: 157
Joined: Sun Jun 07, 2015 10:44 pm

Re: drenching root mealy bug

Postby mary44 » Tue Sep 12, 2017 2:50 am

Hello Allan and Limania,

I appreciate your replies. I only washed the roots of a few lithops (the ones I had bought in unchecked) and rapidly realised the enormity of trying to do this with a rather large collection :shock: And it seemed to me that doing so might kill more than it cured at this point in the season. I hear you regarding the thought of an October drenching Alan, probably not wise unless we get a very warm autumn.

My drenching is only partly done due to the amount of chemical required to soak through so many large pots... I found 8 litres of diluted chemical went nowhere... and have just bought some more chemical so round 2 of primary drenching will happen sometime this week.. Time permitting.

So it sounds like giving all pots a good drench with chemical now a.s.a.p and then waiting until they are ready to be watered next year and then drenching again and repeat 3 weeks later to ensure all are dead.... It is made more complicated by waiting until the leaves have been reasbsorbed before watering.

I hope that the initial drenching will kill sufficient mealies for them not to decimate my collection in the mean time. To be honest they all look very healthy, the mealies do not appear to have caused any damage despite being a large infestation. I would not have known if I hadn't suddenly decided to do some repotting.

Some of the plants were so incredibly badly infected I just gave up and cut the roots off and planted them with just a short stalk of root remaining in the hope they will reroot themselves. An experiment I may regret later.. None of these plants were my special lithops I hasten to add, if they die it will not be the end of the world...

Australian
Posts: 353
Joined: Thu Jul 16, 2015 12:08 am
Location: Australia

Re: drenching root mealy bug

Postby Australian » Wed Sep 13, 2017 7:38 pm

I recently bought a product called Microbe Lift TMC which is supposed to take care of infestation to root systems of plants. It's like lactobacteria which attack eggs of insects so they cannot attack roots. It is harmless to plants. I still need to try it though.

mary44
Posts: 157
Joined: Sun Jun 07, 2015 10:44 pm

Re: drenching root mealy bug

Postby mary44 » Sat Sep 16, 2017 9:00 am

Well I used up 2 large bottles of bug clear vine weevil drench today, and still have almost half the Lithops to go.... :shock: I will be doing this forever, haven't even thought about the cacti lol.

mary44
Posts: 157
Joined: Sun Jun 07, 2015 10:44 pm

Re: drenching root mealy bug

Postby mary44 » Sat Sep 16, 2017 9:01 am

Australian wrote:I recently bought a product called Microbe Lift TMC which is supposed to take care of infestation to root systems of plants. It's like lactobacteria which attack eggs of insects so they cannot attack roots. It is harmless to plants. I still need to try it though.

That sounds a great idea if it works.


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