Caused by cochineal (the same bug used to make red dye). They will eventually kill the cactus. You can try using a hose to physically spray off as much as you can, then spray it with soapy water. May need several treatments.
I work downtown and a lot of the cacti around my office slowly died of this last year. 🙁
coolcaiti
They don’t mean a death sentence for the cactus, in fact they’re native to cacti and only to cacti so if that were true, there would be none left. You have a totally manageable amount on there, and if it gets super covered you can literally wipe them off with your finger if you think it’s ugly. Personally, I believe that the cactus is there for the bug, not just for you, so it’s great that they’re on there. It’s also a really fun and cool thing to tell people what they are and that they’re what make m&ms and Skittles red. In short: if you’re a naturalist who wants to invite native flora and fauna, then you’re doing an amazing job and I’m stoked for you. If you want the prickly pear/cactus to be a flawless specimen, then… maybe plant a cactus you care less about a few feet away and transplant them 😉 haha
56473829110
Spray with insecticidal soap (neem oil won’t do shit) and gently but thoroughly scrub, spray with a decently high pressured hose nozzle (but NOT a pressure washer) and spray with insecticidal soap, again.
Repeat this over and over until you do not see them any more (or as best you can – with spines you probably won’t be able to scrub all of them – spray those with the hose then soap)
Once the population is severely knocked back, cease using insecticidal soap and introduce **native** ladybugs (including Lindorus lophanthae if you can find them) and lacewings.
Edit for note: please don’t use stronger insecticides and/or systemic insecticides. And don’t spray any – including the soap – while the cactus is flowering.
Texas_Naturalist
I just hose these off every few months and the cacti are fine.
5 Comments
Harvest those bugs and make some deep red dye.
Caused by cochineal (the same bug used to make red dye). They will eventually kill the cactus. You can try using a hose to physically spray off as much as you can, then spray it with soapy water. May need several treatments.
I work downtown and a lot of the cacti around my office slowly died of this last year. 🙁
They don’t mean a death sentence for the cactus, in fact they’re native to cacti and only to cacti so if that were true, there would be none left. You have a totally manageable amount on there, and if it gets super covered you can literally wipe them off with your finger if you think it’s ugly. Personally, I believe that the cactus is there for the bug, not just for you, so it’s great that they’re on there. It’s also a really fun and cool thing to tell people what they are and that they’re what make m&ms and Skittles red. In short: if you’re a naturalist who wants to invite native flora and fauna, then you’re doing an amazing job and I’m stoked for you. If you want the prickly pear/cactus to be a flawless specimen, then… maybe plant a cactus you care less about a few feet away and transplant them 😉 haha
Spray with insecticidal soap (neem oil won’t do shit) and gently but thoroughly scrub, spray with a decently high pressured hose nozzle (but NOT a pressure washer) and spray with insecticidal soap, again.
Repeat this over and over until you do not see them any more (or as best you can – with spines you probably won’t be able to scrub all of them – spray those with the hose then soap)
Once the population is severely knocked back, cease using insecticidal soap and introduce **native** ladybugs (including Lindorus lophanthae if you can find them) and lacewings.
Edit for note: please don’t use stronger insecticides and/or systemic insecticides. And don’t spray any – including the soap – while the cactus is flowering.
I just hose these off every few months and the cacti are fine.