Spots on an opuntia

[Carpkel]

I have unknown spots that form on my opuntia. Some areas are heavier than others. I have had it on the cactus for at least two years and does not appear to affect its health. It is not mealy bugs and does not appear to be scale. Also it does not spread to other cactus.
It sort of resembles the spots on an astrophytum ornatum. Could this be the same as the spots on astrophytums?
I have never heard of opuntia getting spots like the astrophytums

[Tom in Tucson]

My 1st reaction is that the combination of light specks, and tan colored patches, is reminiscent of a soft scale (parasitic) infestation. I would begin a standard Malathion application routine.

[Carpkel]

I will do that. Thank you

[Steve Johnson]

20231115_185859_copy_750x1000.jpg (71.48 KiB) Viewed 3292 times

Appears to be Cochineal insect, which is a type of mealybug. See this:

https://www.cactiguide.com/cactipests/#cochineal

I was around Malathion a lot in the 1970s -- nasty stuff (and it smells nasty too), so I wouldn't recommend it. BioAdvanced has a 3-in-1 spray you can buy on Amazon:

https://www.amazon.com/BioAdvanced-7012 ... r=8-1&th=1

Spray at night while the stomata of your Opuntia are open -- this gets Imidacloprid into the skin. Since Imidacloprid is toxic to mealies (including Cochineal), spraying on a regular basis should keep the problem under control until you can give the plant a soil soak in the growing season. Applying insecticidal sprays in the house must be avoided, so if this is a problem for you, use Isopropyl alcohol instead.

[Carpkel]

Thank you, Steve johnson,, I will do that.