Hi, Jan! It does look like scale on all of the plants. You can try rubbing them off with a Q-tip dipped in 50% rubbing alcohol. Although several plants look to be infected, and yes it will spread, you don't appear to have a heavy infestation. If you choose to use the alcohol method you will need to keep an eye on your plants for their return from eggs that are probably already there.

If I just find one or two on my plants, I try the alcohol first. If a lot of my plants are impacted, I go ahead with a drench. I use Bayer 3-in-1. Any pests that nibble on my plants are then killed and cannot multiply.. It protects for 3-6 months.

Others may have a different idea for treatment. Good luck!

Hey Crenda, thank you for your recommendation:) I have to trouble you if these questions below as most answers I found are directed to rose plants and other type of ornamental plants. My plants are succulents. Can you share how often you use to spray this on an infested plant in a day? Is this to be carried on until it has stop spreading? Does the soil need to cover during spraying? Can this be used as health maintenance/prevention of pests for succulents? I intent to get a bottle of ready to use 3-in-1. Thank you once again.

Hi guys, truly appreciate advise for the following:

I have circled the picture leading to the problems of the pad.
Is this a disease ? Can it be pass on to another cactus / succulent?
Can the health of this plant be reversed?

Please help! and thank you in advance:))

I am not sure there are scale on most of your plants, merely spots which occasionally appear on succulent leaves. Perhaps it is a scale on the last of the photos but the others do not appear to be a regular shape or appearance typical of scale. If it is just a few, try scraping them off rather than use chemicals. I sometimes get some scale on my Aloe plicatilis but just rub them off the leaves with my fingernail.

The marks on the Opuntia pad look like normal marks which occur on older pads for no obvious reason. I wouldn't worry about these.

Dear S G, thank you so much for your comment:)
When come to infestation i am pretty loss.
I tried scraping and using water to flush it. It doesnt help. Is it safe to use alcohol and also place it together with other succulents?

If it doesn't scrape off, then I don't think it is scale, just a scar from some physical damage. Why try alcohol if it doesn't appear to be scale?

Separate it from other plants if it makes you feel better, otherwise just keep an eye on them to ensure it doesn't spread.

Thank you SG:) i will try your recommendation:))
I havent get a chance to see it turn purple, hope this plant stays and grow.