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.