Woolly Scale Insect

These horrors have been a problem on my citrus trees since the spring. I was relying on the paper wasps, ladybirds and lacewings to polish them off, but it's not working. Although I can clean individual leaves on the lemon, limes and orange, I can't even begin to tackle small-leaved and thorny trees like satsuma and caviar limes. Has anyone had any experience of using a detergent/oil/water mix on them? It's the standard go-to 'remedy' for everything here, now that insecticides are banned, but does it work on scale/woolly scale? I certainly don't want to go down the systemic route, which I would do on ornamentals.
The other question that springs to mind is: If that mixture works by clogging the pores and respiratory organs of the insects, does it also clog the stomata (pores) of the plant's leaves and do more harm than good? TIA for any thoughts.....

 

Cant help much really, I'd just spray with something systemic if its going to be a few months before you pick any fruit.

 

In the old days would have been tar oil winter wash and a systemic in the growing season.
You could consider Neem Oil it seems to be recommended for most pests.
I use an Organic Insecticide based on various organic acids, smells a bit like linseed oil, does it work to an extent yes. Mainly gets used on greenfly on plants overwinter in the greenhouse.

 

Thanks both! The usual recipe here is savon noir (black soap), colza oil and water. Might have a go at replacing the colza with neem oil for the large-leaved ones and see what happens. No issues that you know of @NigelJ with the leaves getting clogged up?
A few of them, like the kaffir lime, mandarin and tiny pink caviar lime fruits I don't use, so will try to track down something systemic for them. The pesky things have got to go before late autumn when the trees will be packed in under the roof along with all the tender climbers! They've already infected a Hymenosporum

 

Oh @noisette47 - the tiny caviar limes are brilliant - the little blobs rise and fall in a G&T like a miniature lava lamp and give a pop of sharpness. So please try them and delay the systemic!
I have used cotton buds dipped in methylated spirits to rub off scale, but it's a tedious process, and you always miss some.

 

Hi Caroline It's true that the pink caviar limes have the authentic 'bubbles', but I tend to use the green ones more. Those and sweet limes for the Mojitos I'll harvest and freeze what's there, though.
I've spent all summer poking the egg sacs off with a pointed stick, and squashing them, but even with the help of the wasps, it's a losing battle. A combination of scale and leaf miners is too much!
Hope you've had a good summer

 

Just had a dig around and you might like to look at https://backyardgardengeek.com/can-you-use-too-much-neem-oil-on-plants/
and What should neem be used for on plants?

 

Just a quick update...after reading up on neem oil, I tried an experiment with Melia azedarach. It's loosely related to Azadirachta indica, the true neem tree.
I macerated leaves and fruits for a couple of days and mixed the resulting liquid with savon noir. Sprayed the trees yesterday. It certainly smelt effective! Will need to repeat the treatment to break the life-cycle of the little beasts, but fingers crossed! If it works, my two big Melia trees will be a never-ending source of joy (They are anyway, but it's lovely when something turns out to be useful as well).

 

I used Neem oil 2 years to clear up a problem of woolly aphids on my Amaryllis plants. I'd lost a lot of my bulbs due to this pest that I couldn't get rid of till I read somewhere about using Neem Oil. It's a bit laborious to set up but once you start to use it you will find it does the job! Being organic it doesn't damage the environment either nor does it kill beneficial insects if used in the right way. It cleared up the problem on my Amaryllis & they haven't returned again & my stock of plants is heathy again & rebuilding their numbers.

 

The thing is...here in France, we tend to get all the scams going, in the name of 'bio' and 'eco-friendly' this, that and the other. After looking at the available 'neem oils', some of which were derived from Murraya, so not even the right tree, I reckoned it was worth a try using Melia. It does seem to have worked and has repelled the wasps too This could be an extremely useful tool in the never-ending battle with France's myriad of nasty insects

 

@noisette47 It's not much different over here either! There are so many people who want to trick you out of your money! I'm very suspicious of all these claims & like to read other people's opinions & investigate a bit for myself before giving up my cash!