Avid knocks 'em out quickly and efficiently.

It won't be too strong will it? Will it damage the plant at all? I've heard several pesticides will be too strong for the cactus's skin.

Your photos are not too convincing, in my opinion. These red mites you see...do they move around quickly? Predatory mites, which I have seen on occasion, scamper around readily. They are beneficial. Bad mites barely move, when you blow on them gently they get agitated and start to move some more.

If you think you have bad mites, before you resort to harsh chemicals, make sure your cactus plants are being watered well. Sucking animals prefer dehydrated plants because the juices are more concentrated. Also, frequent spraying of plain water on the skin may be enough. Do this twice daily for a few weeks, it really seems to disrupt them. It's easier with cactus plants, than it is with leafy plants which need spraying under the leaves.

Situate your plant outdoors for as many months as possible if you can. Fresh air and rain cures many ills. Plants kept indoors in stagnant air are not healthy.

x

If it isn't mites then what is causing all the scarred up parts on my plant? I water it once or twice a week so I don't think it's dehydrated.

You would see fine spider-type webbing, were it red spider mites.

There are a few wispy webs around some of the damaged areas

Though I have never tried it on cacti, on other plants I have used a dilute solution of dish detergent spray to wipeout mites.

However, as X mentioned, you should make sure that the issue is actually mites and that the mites you are killing off are not the predatory mites. The bright red mite you photographed on the lip of a pot is a predatory mite. Besides being large for a mite and screaming red in color, predatory mites can easily be recognized by their movement. As X mentioned, spidermites and other pest types move around slowly and only if they must. Predatory mites tend to scurry all around -- not unlike someone who is late for work trying to find their missing car keys.

I asked my grandpa and he said to spray a half and half mix of original listerine and water onto my cactus and that worked like a charm! I have noticed no further damage from whatever pest was harming my cactus. Thanks for everyone's help and insight. :)

I asked my grandpa and he said to spray a half and half mix of original listerine and water onto my cactus and that worked like a charm! I have noticed no further damage from whatever pest was harming my cactus. Thanks for everyone's help and insight. :)

Not spider mites. Go out around dark and kill the slugs that are eating the epidermis on your plants. Been there, have the scars.

Slugs really like the skin on Opuntias, Peniocereus and Oreocereus, rarely bother Mammillarias and Ferocactus, eat Rebutias wholesale. You will find the flowers will open damaged on all cactus species. Slugs hide under the pot and come out at dark or before if it is raining.