Armoured Scale

[BruceM]

Armoured Scale - What is your method? I've bought a few plants that have scale, picked off what I could see and bought some Chilocorus nigritus to aid in finding those I can't. I doubt they will stay in the greenhouse for that long (even with netting over the door). So, does anyone know a systemic that would kill them/cover those that the bugs miss? Nothing I read online seems to suggest much to kill armoured scale (systemically).

[iann]

Acetamiprid. Not most other neonicotinoids. Which is lucky because it is one of the few left for sale. Also Dimethoate which you could try as a last resort, not because it won't work but because it is hard to find, expensive, not strictly legal, and more toxic. Other organophosphates are also effective but even less likely to be available.

Failing that, use a dormant oil and hope it doesn't kill whatever plants you spray it on.

[BruceM]

Excellent, thank you Iann. Dimethoate is cheaper than the 25 ladybirds, hopefully they will be some use!

[iann]

Excellent, thank you Iann. Dimethoate is cheaper than the 25 ladybirds, hopefully they will be some use!

For a small gratuity, I'll collect 25 ladybirds for you

BTW, the dormant oil suggestion was not entirely serious and that might not have been apparent from my post. It will burn green plant material, and probably kill many succulents outright. It is designed for dormant deciduous trees and shrubs.