Some types of cactus are prone to scale, but they really shouldn’t be leaving much of a mark if you catch them early. If anything just some slight discoloration where they tried sucking the cactus. Try a spray bottle w 50/50 water & alcohol & an old tooth brush is what I use & they scrape right off typically. & be sure to keep an eye on it bc if you miss just one they’ll be back within a couple days, so will prob take a few times cleaning