Despite being generally robust plants, cactus can experience some problems. Your cactus plant may have white fuzz spots as a result of a bug infestation. Be sure to take quick action to prevent serious harm to the cactus.
What exactly is the white, cottony substance on cacti?
The substance that appears to be cotton fibers is actually a fine wax made by adult cochineal scale insects, and the little black specks may be their nymphs. On cholla (Cylindropuntia spp.) and prickly pear (Opuntia spp.) cactus, it is typical in this region. The white beards that resemble those on other cacti, such as the Peruvian old man (Espostoa lanata) and Peruvian old woman (Espostoa melanostele), are not an insect byproduct but rather typical, healthy changed tissues. Landscape chollas and prickly pears have a white waxy coating produced by cochineal scale that helps shield these actual bugs from predators and insecticides.
I’ve seen prickly pear pads covered in that white fluff almost entirely. Mild infestations, like the ones Doa Ana County Extension Master Gardener Dael Goodman and I saw at in Las Cruces earlier new week, are more typical. In New Mexico, there are multiple native cholla and prickly pear species. There are numerous of them in the Goodmans’ front yard, and we immediately noted that some species were more affected by the cochineal scale than others.
Topical pesticides, especially natural ones like petroleum oils and insecticidal soaps, are unlikely to be effective no matter what time of year it is if the insects are shielded by a white covering. Also, keep in mind that the ultimate goal isn’t to completely eradicate cochineal scale from your garden—partially that’s impossible—but rather to control the populations of insect pests until beneficial insects come to the rescue.
You will be shocked to see a bright red liquid that seems to appear out of nowhere if you squeeze a glob of the white goo that has healthy females hidden inside. Carmine, a natural dye used for millennia to color textiles and create artwork, is produced inside the bodies of cochineal scale insects. Because this carmine component is also utilized in red foods and cosmetics like sausages, lipstick, pie fillings, and vividly colored alcoholic beverages, check product labels for it. Before the firm converted to an artificial dye in 2006, it was used to create the vibrant color of Campari liquor, but a new generation of craft distillers and other producers are increasingly adopting it as a substitute for synthetic red components.
Goodman and I attempted to film the flowing red fluids squeezing the white tufts on her prickly pear pads with a small stick, but we hardly noticed any redness. The female cochineal population may be declining at this time of year, or those specific tufts may be so old that the residents have long since disappeared and have only left that waxy material behind. We’ll give it another go with a fresher sample in the summer.
Six cholla species and seven prickly pear species are covered in Robert DeWitt Ivey’s stunning reference work Flowering Plants of New Mexico. There are five yellow-flowered prickly pears in that group. Identification might be aided by paying close attention to the pad sizes and spine specifics. If you intend to approach closely, make preparations and carry tongs.
At the Agricultural Science Center in Los Lunas, Marisa Thompson, PhD, is the Extension Horticulture Specialist for New Mexico State University.
Why is my cactus fluffy white?
We apologize, but Mr. Smarty Plants needs some time to catch up after receiving an overwhelming amount of mail. Soon, we hope to be taking new inquiries once more. I’m grateful.
ANSWER:
Before, Mr. Smarty Plants responded to a query regarding cholla cactus cochineal bug management (similar to your prickly pears). What Larry and Brigid Larson wrote is as follows: Cochineal feeding can harm the cactus and occasionally result in the host plant’s death. The Cactus Doctor talks about getting rid of cochineal. Their advice is as follows: 1) A hose with a power nozzle attached to the end. 2) It was advised to clean the affected areas with insecticidal soap or unscented dish soap to treat them if the infestation gets out of hand. Neem oil was also mentioned as a possible natural remedy.
In response to another Mr. Smarty Plants query about cochineal bugs on prickly pear cactus, Nan Hampton provided the following response. (As you can see, this is a common query.) It sounds like cochineal bugs are infesting your cactus (Dactylopius sp.). They are cactus-eating small scale insects. They generate fluffy white wax that covers their body as they consume the cactus and shields them from predators as well as the weather (especially drying out). The fluffy wax also acts as a sail or balloon to carry the bugs to a fresh cactus patch in the breeze. The carminic acid that the bugs create aids in shielding them from predators, particularly ants. Indigenous peoples of southwestern North America, Central America, and subtropical South America have been using this bug’s carminic acid for centuries—possibly millennia—to synthesize a vivid red dye that they utilized to create exquisitely colored fabrics. Cochineal bugs were formerly only found in the New World. The cochineal bug spread around the world when European explorers came to a place and saw the stunning red cloth made by the locals. Although they have also been employed to help reduce cactus populations, the need for cochineal bugs decreased when a synthetic red color was created. But recently, there has been a resurgence of interest in cochineal bug cultivation for red dye because it was discovered that synthetic red dyes can have harmful side effects on health. Today, food coloring and cosmetics both employ the bug-derived dye. Because of this, managing cochineal bugs hasn’t really been a top concern, and as a result, I haven’t been able to discover a lot of information on managing them. If you only have a minor infestation, I advise scraping them off (slowly, to avoid the cactus spines) and throwing them away. They might also come off with a water under pressure wash. To ensure that you don’t harm your cactus, test a tiny area first. Then, collect and get rid of any insects that you wash off the cactus.
The University of Arizona Extension also suggests a similar set of remedies in a publication on cactus diseases.
The usage of insecticides was discussed on multiple websites, and Wikipedia included several natural predators: “The population of the bug on its cacti hosts can be lowered by a variety of natural enemies. Insects appear to be the most significant group of predators. Numerous parasitic wasps as well as predatory insects including ladybugs (Coleoptera), different Diptera (like Syrphidae and Chamaemyiidae), lacewings (Neuroptera), and ants (order Hymenoptera) as well as pyralid moths (order Lepidoptera), which kill cacti, have all been identified.”
Here is more information on the intriguing world of the Dactylopius coccus cochineal scale insect and the carmine dye that was highly sought for fabric dyeing in the 15th century.
How should a white fuzz cactus be cleaned?
White fuzz on cactus can hinder their growth and lessen their visual attractiveness. What then creates the white fuzz on cacti, and how may mealybugs be removed from cactus plants?
Pour rubbing alcohol into a garden spray bottle after combining water and rubbing alcohol in a 1:3 ratio. To get rid of the bugs, spray all the cactus that are covered with white fuzz. You might also add ladybugs to your cactus to eat the mealybugs and get rid of the white fuzz on the plants.
I’ve used the Bazos ladybugs on my plants, and they work incredibly well at organically removing mealybugs and other damaging pests like aphids. You can use them if you don’t want to use pesticides on your indoor plants and outdoor gardens.
How can powdery mildew on cacti be removed?
Depending on the type of succulent you have and the severity of your powder problem, you can utilize a variety of efficient powdery mildew treatment techniques.
The following methods for treating powdery mildew on succulent plants have been shown to be effective.
Neem Oil
Simply combine one tablespoon of neem oil with a gallon of water, and spray your plants with the mixture every two weeks until the powdery mildew on the leaves of your succulent plants is gone.
Dish Soap and Water
Use an eye dropper for small plants or, if you have one, a spray nozzle attachment to apply the liquid to the succulent leaves after thoroughly mixing it up.
Powdery mildew will be quickly eliminated by using this kind of treatment, but you should take care not to get any dish soap solution into the soil as this could harm the roots.
Baking Soda
Simply mix one tablespoon of baking soda with one gallon of water, and then mist the solution onto the leaves of your succulent plants every two weeks to eradicate powdery mildew.
Hydrogen Peroxide
Half a gallon of water should be mixed with one teaspoon of hydrogen peroxide powder. Once the powdery mildew is gone, repeat this procedure every two weeks on the leaves of your succulent plant.
For each use, it is advisable to prepare fresh hydrogen peroxide solutions because, once mixed with water, it loses its effectiveness after a few days.
Insecticidal Soap or Horticultural Oil Spray
Mix one spoonful of powder into a gallon of water before using insecticidal soap or horticultural oil sprays.
Use an eye dropper for small plants or, if you have one, a spray nozzle attachment to apply the solution to the succulent leaves.
This method of treating powdery mildew will quickly eliminate the fungus, but be careful not to get any powder mixture into the soil as this could harm the roots.
Remove Powdery Mildew Infected Leaves
Get rid of powder-covered leaves as soon as you notice them to help prevent powdery mildew on plant leaves.
If the infection is stopped before it spreads to other healthy succulent plants, it may even help to stop an infestation.
Mouthwash
Simply combine a few drops of mouthwash with a gallon of water, then spray the mixture into the leaves of your succulent plants every two weeks to eradicate powdery mildew.
As effective as many other commercial powder treatments is the mouthwash powder blend. Still, it also makes them taste like mint, which helps prevent deer, rabbits, raccoons, and squirrels from eating all of your succulents!
How did mealybugs get on my cactus?
Mealybugs come in a variety of species all over the world. All can be discovered in damp, humid environments. This is why they target indoor plants so frequently. If you notice mealybugs on your cacti, this can be a sign that you’re keeping them a little too damp.
Succulents and cactus dislike humid environments. Mealybug infestations, fungal, bacterial, and viral illnesses, as well as overwatering, weaken and weaken cactus plants.
Is my cactus infested with mealybugs?
When there are several white spots or little white fuzz bits adhering to your cactus, it is most likely that your plant has mealybugs. To make sure, you’ll need to approach near to your plant.
If your cactus has white fuzz specks all over it, you have mealybugs.
By the time you detect this, there will probably be sooty mold or fungus growing, spots that appear glossy or damp (from their excretions), and worse. This is the outcome of the bugs’ production of honeydew.
If there are areas of your soil that appear moist despite the fact that you haven’t watered them, mealybugs may be present in your soil or at the base of your plant.
Your cactus could begin to appear less healthy overall, start to turn yellow or brown, and begin to lean to one side.
Mealybugs can be seen up close with the naked eye and are, at their biggest size, about the size of a pinhead.
These little cactus bugs can be recognized by their dull gray hue and lined back before they settle in and feel comfortable (almost like a hasselback potato).
They create a barrier around themselves for protection and to lay their eggs once they have found the ideal location and are comfortable. This appears to be little cotton-fluff particles.
Male mealybugs can fly in some species, but they mostly transmit by crawling from one plant to another.
Therefore, if you have numerous plants near together or touching foliage, they might spread considerably more quickly.
It’s likely mealybugs if your cactus has white patches or tiny dots that resemble white bugs.