Good evening. Two days ago I noticed these spots on my Santa Rita Prickly Pear. Are these spots insects? Any suggestions on what to do? I bought this plant at Cactus Jungle and it’s one of our favorites.
Those spots are insects – Scale insects – the big spots are the adults and the tiny spots are the babies. Prickly Pear Cactus are prone to these and it’s fairly common in the Bay Area. We recommend starting off by dipping a soft-bristled paintbrush into rubbing alcohol and gently brushing as many of them away as you can. The alcohol will break through their shells.
As this is a fairly extensive infestation, you should use a strong insecticide – we recommend natural pyrethrins (not the synthetic varieties) and we do sell a couple brands that are safe for use on cacti – that you can spray on directly. You will need to get into the cracks and crevices around the plant, and even spray the top of the soil. Re-spray after 2 weeks and that should take care of it.