Above ground mealybugs without pesticides

[SpriteFish]

Hello! I'm in the process of repotting all of my succulents with a new potting mix, and moving all of them outside. When I had my plants indoors, I thought I wouldn't need an area dedicated to quarantining plants... Long story short I have alot of foilage mealybugs, amd I'm yet to discover if they also have root mealies.

I know this will probably be difficult, but I want to try to treat this without using pesticides due to the numerous drawbacks due to pesticide toxicity. I can use IPA, hydrogen peroxide, and dish soap, even though realistically they won't be harmless either. I will also be taking precautions such as doing treatment at night when pollinators aren't active, and prepaphs keeping my plants indoors for a few days after treatment. My assumption is these methods would act as a contact insecticides, instead of a systemic insecticide, which should mean it's less harmful due to the pesticide not staying in the plant for ages after treatment. (My current understanding of systemic insecticides, is that they've been found to stay in the plant for awhile after treatment, so you can't put them outside a week after treatment)

I've tried to look for less damaging pesticides, but the reality is that even pesticides deemed 'less toxic' to benefical insects, still cause significant harm, and instead of outright killing benefical insects they greatly impair them, eventually causing the population to drop. I even looked at neem oil, and while people use it as a more environmentally friendly pesticide, it's still toxic. The only article I could find that said neem oil wasn't toxic, was one that instead used 'weasel words' and said it was "Practically non-toxic" which is weird to say the least.

Because my plants will be going outside, I dont want to use any of these options. So, I need advice from people here. Here are the methods I've seen for treating mealybugs, if you have advice on wjich to follow or of I should do multiple im all ears! (when I refer to diluted IPA, I mean a dilution anywhere from 50% - 70%):

. Scrub them off with a toothbrush or blast them off with a hose

. Dip a q-tip in diluted IPA (Rubbing alchol is 70% IPA), and use it to wipe off all the mealybugs you can see.

. Spray a plant with diluted IPA (some places say just to use diluted IPA, and others suggest add a little dish soap to help break the pests protective shell, what do you think?). One place I saw recomended to wash the IPA off after 10m, while others didn't. Of course while using IPA the plant must stay out of sunlight to prevent phototoxicity. I also saw differnt places recomend differnt dilutions, although it was always under 70%.

. Pest and insect repellant is listed as one of the plant related used for hydrogen peroxide, so prepaphs this could work: Pests and Insect Repellent (including Fungus Gnats!)

Use during watering for root pests, or as a spray to repel insects that feast on leaves.

For larvae and pests living in potting mix: Wait until top layer of potting mix is dry and plant needs watering. Mix 1:4 ratio. 1 part Oxygen Plus 3% to 4 parts water (eg: 1 cup to 4 cups). Either spray or saturate soil by bottom or top watering as normal. Depending on the insect, adults may continue to lay eggs, so best used in conjunction with treatment such as sticky traps to kill adults also.

For pests that live on and eat leaves: Mix 1:1 ratio. Lightly spray the entire plant. Best used in a fine mist spray bottle. Spray only (do not pour on leaves). Do a spray test first on a couple of leaves, 2 days before treating the rest of the plant.

Whether used as a foliar spray or for treating the substrate, use Oxygen Plus by itself with water (do not mix with other products such as fertiliser).



Seeing how many differnt methods there are, I'm realizing like other subjects in planting, pest control will also require some experimenting.

Along with wondering what method I should use for the above ground mealies (I know how to take care of the root mealies if I find I have them), I'm also wondering what order to do things in. Should I unpot all of my plants, and then treat both the above ground and (if they have them) root mealies, and only repot once both are gone? Or should I unpot all of my plants, treat any root mealies I see, and then repot them even while they still have above ground mealies?

Thank you for reading, hopefully you all will have some advice! Also if you know of other methods that have less downsides I'd love to here, I'll put in all the work needed to do this without pesticides.

[jerrytheplater]

I once had a root mealy infestation during the winter dormancy-maybe December or January. I unpotted all of my plants and soaked/submerged them in a 2% soap solution mixed with Malathion for less than 30 minutes. I don't remember how long really because it was probably in the early 1990's. I know you don't want to use the chemicals, just letting you know what I did. I did not rinse them.

I dried the plants off by laying them on newspaper sheets and moved them around and changed the paper until they were dry. Since they were dormant, I did not repot them until Spring. I did check them weekly to be sure I didn't see any more mealies. Don't remember if I saw them.

I had another infestation last Spring on a Trichodiadema purchased at a big box store. I must have missed it, so it spread to another Trichodiadema. Both were in 2" pots. I treated them manually using only a commercial soap solution made to label concentration. I sprayed the whole plant and then used a fine paint brush and a magnifying headset to look for the mealies and to spot apply the soap. (The magnifying glass is kind of like a pair of glasses. It clamps around your head and fits over my normal glasses. It can flip up and out of the way too.) After treating them, I picked them off with tweezers. I had to treat weekly. On the succeeding weeks I used my fine tweezers and the magnifying headset to pick off the bugs. I ended up pulling away the dead remains of bark and branches as I looked for the mealies. I probably spent 45 minutes examining each of the two plants every week for maybe 5 weeks. The weather finally warmed up to allow me to move the plants outside and natural predators like spiders finished the job. They are growing well now and are mealy free.

It is a laborious job to do it chemical free. But it is possible.

[keith]

Spray a plant with diluted IPA (some places say just to use diluted IPA, and others suggest add a little dish soap to help break the pests protective shell," the IPA breaks the waxy coating the soap dries the insect out .

3% Hydrogen peroxide wont do anything in my experience. If you have root mealies you could add diatomaceous earth to your mix it may help.

The IPA and the soap will take care of the mealy bug if it doesn't add nicotine I have a video on this. cactusduty on youtube

[Steve Johnson]

Spray a plant with diluted IPA (some places say just to use diluted IPA, and others suggest add a little dish soap to help break the pests protective shell," the IPA breaks the waxy coating the soap dries the insect out...

The IPA and the soap will take care of the mealy bug if it doesn't add nicotine I have a video on this. cactusduty on youtube

Question for you, Keith -- will IPA (AKA rubbing alcohol) and a dilute soap solution kill above-ground mealy eggs too? If so, excellent. If not, the problem will be mealy eggs hatching into new generations of mealybug, in which case a further discussion with SpriteFish here would be a good idea.

By the way, some growers refer to what they call spine mealies -- those are actually mealybug egg sacs. Although it's a bit labor-intensive, you can remove them from the spines with a pair of tweezers.

[SpriteFish]

I sprayed the whole plant and then used a fine paint brush and a magnifying headset to look for the mealies and to spot apply the soap. (The magnifying glass is kind of like a pair of glasses. It clamps around your head and fits over my normal glasses. It can flip up and out of the way too.) After treating them, I picked them off with tweezers. I had to treat weekly. On the succeeding weeks I used my fine tweezers and the magnifying headset to pick off the bugs. I ended up pulling away the dead remains of bark and branches as I looked for the mealies. I probably spent 45 minutes examining each of the two plants every week for maybe 5 weeks.

I think my plan is similar to this at the moment. Scrub the mealies off with a spare toothbrush, spray with diluted IPA and dishsoap and keep out of sunlight while drying, and then keep inspecting and physically removing mealies once a week for about 5-6 weeks. I wonder if it would be worth also spraying with IPA once a week while also physically removing them, or if that would be too much.

Also speaking of magnifying glasses, I'm thinking of ordering one to keep an eye out for pests (especially mites!).

the IPA breaks the waxy coating the soap dries the insect out .

3% Hydrogen peroxide wont do anything in my experience. If you have root mealies you could add diatomaceous earth to your mix it may help.

Awesome, I've just ordered some more spray bottles for my plants and for cleaning, so I'll dedicate one of them to an anti mealybug solution of IPA and dish soap.

I'm wondering what order I should do things in. I have to repot all of my plants, so I can also take that opportunity to check for root mealies. But if I were to find that they didn't have any root mealies, and only had foilage mealybugs, should I repot them into fresh potting mix right away, or hold off repotting until I get rid of the foilage mealies to avoid them infecting the new pot and potting mix? (For reference it is the growing season at the moment)

[jerrytheplater]

This magnifier is not what I have, but it looks pretty good. https://www.amazon.com/Magnifying-Glass ... SY3VT?th=1

[keith]

will IPA (AKA rubbing alcohol) and a dilute soap solution kill above-ground mealy eggs too? " I don't know good question might have to repeat if they show up again or add nicotine .

[Steve Johnson]

Hi SpriteFish,

Here's something to consider -- from cactuspath.com (https://cactuspath.com/unveiling-the-my ... d-deserts/):

• "But how do cacti store water? The answer lies in their unique structure. Unlike other plants, cacti have a thick, waxy coating on their surface that prevents water loss. Inside, they have a sponge-like tissue that can absorb and hold water."

Constant application of IPA will break down the waxy coating, leaving cacti vulnerable to water loss. It can also disfigure the skin of many species. Furthermore -- unless someone can tell us for a fact that soap and IPA kill mealybug eggs, those eggs will hatch into new generations of mealies which you'll need to knock down with more soap and IPA. There are only two long-term solutions to the problem, and the one you can get in New Zealand is a neonicotinoid called Imidacloprid. I understand your objection to pesticides, but there's a big difference between using them indiscriminately and using them responsibly in a targeted manner. I'll explain what that means in a moment.

Imidacloprid can be used either as a foliar spray or as a systemic. The long-term solution I mentioned involves applying it as a soil soak for the systemic effect. As Imidacloprid is taken up through the roots, the plant's juices become toxic to mealies, an inside-out approach that scrambles their tiny brains and kills them. And it kills their eggs too. Soil soaks must be applied while the plants are in growth, so when you do it depends on the growing seasons for your cacti and succulents. The systemic effect lasts for 3-6 months.

Imidacloprid has also been known to kill bees in agricultural applications, but this doesn't happen when it's applied responsibly for home use. Here's how to do it:

• When you do the soil soak, use a large container to capture the Imidacloprid-laced runoff from each pot. Make sure that the pot stops dripping. I use a large cake pan so that I can soak several pots at a time.

• Take the runoff in the container, pour it into an empty jug, and keep it in a safe place.

• Take the jug to a local hazardous waste center for disposal.

Not sure where you can go, but this may help:

https://www.gw.govt.nz/environment/land ... ing-waste/

I think Agrecovery is your best bet for finding a place to dispose of Imidacloprid-laced runoff water, so check out that section in the link.

If you decide to go with my Imidacloprid recommendation, find the product you'd like to use, give me the percentage, then I'll give you the proper dilution.

[SpriteFish]

Here's something to consider -- from cactuspath.com (https://cactuspath.com/unveiling-the-my ... d-deserts/):
"But how do cacti store water? The answer lies in their unique structure. Unlike other plants, cacti have a thick, waxy coating on their surface that prevents water loss. Inside, they have a sponge-like tissue that can absorb and hold water."
Constant application of IPA will break down the waxy coating, leaving cacti vulnerable to water loss. It can also disfigure the skin of many species. Furthermore -- unless someone can tell us for a fact that soap and IPA kill mealybug eggs, those eggs will hatch into new generations of mealies which you'll need to knock down with more soap and IPA.

In regards to the waxy coating, it does regenerate right? Breaking the waxy coating would be my main concern with this method, as im alright with having to retreat once a week for 5-6 weeks to wipe out the hatched eggs. Scrubbing the mealies off is another option, but I assume that would affect the coating aswell.

If the waxy coating doesn't regenerate then this will be quote problematic, but if the coating does regenerate it may still be worth treating with IPA. If you know more about the downsides of losing that coating or of it regenerates let me know.

If I do end up finding that this doesn't work, or if affecting the waxy coating is a very big concern, then I will resort to pesticides.

[Steve Johnson]

If the waxy coating doesn't regenerate then this will be quote problematic, but if the coating does regenerate it may still be worth treating with IPA. If you know more about the downsides of losing that coating or if it regenerates let me know.

Can't help you there. I've been using Imidacloprid ever since I did my first soil soak in 2012, and I stopped doing at as an annual preventative once I saw that I simply don't have a mealybug problem after I knocked down a root mealy infestation in 2017. If the mealies ever come back, I'll use Imidacloprid again. I honestly don't know if cacti regenerate the wax on their skins after constant use of IPA, so you'll have to observe the skin and see if it changes color and/or loses its sheen (some species have that sheen, some species don't). If it does and the skin doesn't return to its normal appearance after a short period of time, continuing to use IPA won't be a good idea. And if the waxy coating doesn't regenerate, you'll have to find out about any downsides for yourself.

I put together a very detailed presentation on the subject of mealies, scale, and pest mites, so read through it thoroughly:

https://www.cactiguide.com/forum/viewtopic.php?t=42129

By the way, I stopped doing preventative soil soaks after I updated the presentation in 2022.

I'll mention that Imidacloprid has targeted action against mealies and armored scale, not pest mites. If you encounter red spider mites or flat mites (AKA false spider mites), IPA spray will kill them, but I consider it to be a matter of last resort. If you're unable or unwilling to use a transdermal miticide, IPA is all you have.

[SpriteFish]

I was having a look for more information on IPA and it's effects on the waxy coating on cacti, and found information on its effects on succulents with farina. I'm unsure if something not having an effect on farina would mean it doesn't have an effect on the waxy coating on cacti (unless they're the same thing, as it sounds like they serve the same role), but it's worth noting what I found anyways.

Drenching the bugs with alcohol kills them on contact and their eggs as well. Although it may temporarily dissolve the leaves' powdery coating, I've yet to see alcohol have a lasting impact on the plant.

https://debraleebaldwin.com/pests/how-t ... ucculents/

In case your succulents with farina are infected by bugs, you can treat them using 50% rubbing alcohol and water mix for mealy bugs, then mist it onto farina-covered leaves without any issue.

https://succulentsbox.com/blogs/blog/wh ... CUp8AjVvis



Unfortunately this doesn't automatically mean this information is true, plus both articles dtate contradicting things (e.g one says IPA disolves farina, the other says it has no effect) but it may be worth testing IPA on one of my plants with farina, to see if it has a negative impact. If it does remove farina it will also be interesting to see if the farina can regenerate, although that would take awhile. I did see that the consensus on whether farina grows back is no, or only on new leaves, but there are people saying theyve had it grow back.

It would also be worth seeing if the addition of dish soap makes it have more of a negative impact on farina.

One of these articles also state that IPA can kill mealybug eggs, however there are other articles that say you still have to retreat for when eggs hatch, which implies it doesn't destroy eggs.



I have treated some of my succulents with IPA before, and the mealies ended up coming back. There is however a high chance that this is due to the fact that I didn't treat the pot, and also didn't move the plant, and not due to the IPA itself. I didn't notice any damage to the farina at the time, but I can't say I was looking for damage so there's a good chance I missed it.

[Steve Johnson]

I was having a look for more information on IPA and it's effects on the waxy coating on cacti, and found information on its effects on succulents with farina. I'm unsure if something not having an effect on farina would mean it doesn't have an effect on the waxy coating on cacti (unless they're the same thing, as it sounds like they serve the same role), but it's worth noting what I found anyways.

Drenching the bugs with alcohol kills them on contact and their eggs as well. Although it may temporarily dissolve the leaves' powdery coating, I've yet to see alcohol have a lasting impact on the plant.

https://debraleebaldwin.com/pests/how-t ... ucculents/

In case your succulents with farina are infected by bugs, you can treat them using 50% rubbing alcohol and water mix for mealy bugs, then mist it onto farina-covered leaves without any issue.

https://succulentsbox.com/blogs/blog/wh ... CUp8AjVvis

Unfortunately this doesn't automatically mean this information is true, plus both articles state contradicting things (e.g one says IPA dissolves farina, the other says it has no effect) but it may be worth testing IPA on one of my plants with farina, to see if it has a negative impact. If it does remove farina it will also be interesting to see if the farina can regenerate, although that would take awhile. I did see that the consensus on whether farina grows back is no, or only on new leaves, but there are people saying they've had it grow back.

It would also be worth seeing if the addition of dish soap makes it have more of a negative impact on farina.

One of these articles also state that IPA can kill mealybug eggs, however there are other articles that say you still have to retreat for when eggs hatch, which implies it doesn't destroy eggs.

I have treated some of my succulents with IPA before, and the mealies ended up coming back. There is however a high chance that this is due to the fact that I didn't treat the pot, and also didn't move the plant, and not due to the IPA itself. I didn't notice any damage to the farina at the time, but I can't say I was looking for damage so there's a good chance I missed it.

The dictionary definitions of farina:
1. A fine meal of vegetable matter (such as cereal grains) used chiefly for puddings or as a breakfast cereal.
2. Any of various powdery or mealy substances.
Definition #2 describes the powdery coating on succulents. We'll see its equivalent on Tephrocactus (from the Greek word "tephra", which is ash in English). Waxy and powdery coatings do the same thing -- help the plant to conserve water.

For whatever it's worth, a blogger by the screen name of Simply Bloom at Stone Post Gardens (https://stonepostgardens.com/) makes this claim:

• "Doesn’t the alcohol damage the succulent?
  
  "Nope! The great thing about alcohol, as opposed to other pesticides, is its completely safe for succulents.
  
  "I’ve pretty much soaked some plants in alcohol for a few days in a row because they had a really bad mealy bug plague. They didn't show any signs of burn or damage from the alcohol. The alcohol itself evaporates quickly, so it's just water that remains. The spray bottle won’t get too much on the leaves, so it will dry out before it can do any harm."

That's his or her experience, so this may or may not apply to yours. Simply Bloom also had this to say:

• "A lot of the time, one round of alcohol spray will kill mealybugs if you catch them early. If you didn't quite get them all though, they may come back in a day or two. Continue to spray them until they don't come back.
  
  "If there were a lot of them, you might want to sprinkle alcohol on the ground the next time you water. This will kill any bugs or eggs that are hiding out in the soil." [My emphasis]

While I don't agree with the first part of statement #1, I do agree with statement #2 -- alcohol is a solvent, so the more I think about it, the more I believe that IPA will kill mealybug eggs. And Simply Bloom is correct -- spray not just the plant, but the entire top of the pot.

In case you haven't read my presentation, I'd like to point something out:

Part 3 -- vectors

A simple, yet fancy word for describing how we get pests to begin with...

There's a vector that won't be obvious to inexperienced growers, and it has to do with the fact that 5 of the 6 pests we're discussing aren't specific to cacti. Neighborhood plant life may be the source of your ongoing pest problems, although the list of possible non-cactus hosts is way beyond the scope of this presentation.

Mealies ending up on (and in) your cacti and succulents could be coming from anywhere on your farm -- you may not realize how mobile they are. If they keep coming back again and again even though you're thorough about using IPA whenever you see them, Imidacloprid soil soaks are the only way to go as an effective long-term solution.

[SpriteFish]

Oops, forgot to respond earlier but I'm here now.

For whatever it's worth, a blogger by the screen name of Simply Bloom at Stone Post Gardens (https://stonepostgardens.com/) makes this claim:
"Doesn’t the alcohol damage the succulent?

"Nope! The great thing about alcohol, as opposed to other pesticides, is its completely safe for succulents.

"I’ve pretty much soaked some plants in alcohol for a few days in a row because they had a really bad mealy bug plague. They didn't show any signs of burn or damage from the alcohol. The alcohol itself evaporates quickly, so it's just water that remains. The spray bottle won’t get too much on the leaves, so it will dry out before it can do any harm."
That's his or her experience, so this may or may not apply to yours. Simply Bloom also had this to say:
"A lot of the time, one round of alcohol spray will kill mealybugs if you catch them early. If you didn't quite get them all though, they may come back in a day or two. Continue to spray them until they don't come back.

"If there were a lot of them, you might want to sprinkle alcohol on the ground the next time you water. This will kill any bugs or eggs that are hiding out in the soil." [My emphasis]
While I don't agree with the first part of statement #1, I do agree with statement #2 -- alcohol is a solvent, so the more I think about it, the more I believe that IPA will kill mealybug eggs. And Simply Bloom is correct -- spray not just the plant, but the entire top of the pot.

Do you think it would be a good idea to test out IPA on one of my plants with farina to see how it reacts? If it reacts poorly, then I'll go out and get a pesticide, but I may aswell do a little test first. (I'll also test if the affect on farina is worse with dish soap added)

Mealies ending up on (and in) your cacti and succulents could be coming from anywhere on your farm -- you may not realize how mobile they are. If they keep coming back again and again even though you're thorough about using IPA whenever you see them, Imidacloprid soil soaks are the only way to go as an effective long-term solution.

I have read your presentation (Which in turn alerted me to getting a magnifying to help spot mites, thank you!) and while being on a farm may definitely be increasing the chances of mealybugs, I don't think that's the main reason I got them this time. All of these plants got mealybugs while inside, so I suspect it was due to ventilation, I may very well find that once I move them outside (so that they're more healthy), I'll get more mealies, in which case soil soaks will most likely be what I have to resort to.



In regards to something I said earlier, what are you thoughts on this?

I'm wondering what order I should do things in. I have to repot all of my plants, so I can also take that opportunity to check for root mealies. But if I were to find that they didn't have any root mealies, and only had foilage mealybugs, should I repot them into fresh potting mix right away, or hold off repotting until I get rid of the foilage mealies to avoid them infecting the new pot and potting mix? (For reference it is the growing season at the moment)

This only matters if I find IPA is a good option, but it's worth asking.

[Steve Johnson]

Do you think it would be a good idea to test out IPA on one of my plants with farina to see how it reacts? If it reacts poorly, then I'll go out and get a pesticide, but I may as well do a little test first. (I'll also test if the affect on farina is worse with dish soap added)

Yes -- all growers have to go through a certain amount of trial and error.

I have read your presentation (Which in turn alerted me to getting a magnifying to help spot mites, thank you!) and while being on a farm may definitely be increasing the chances of mealybugs, I don't think that's the main reason I got them this time. All of these plants got mealybugs while inside, so I suspect it was due to ventilation, I may very well find that once I move them outside (so that they're more healthy), I'll get more mealies, in which case soil soaks will most likely be what I have to resort to.

Ventilation issues don't cause mealybug problems, and if I was a betting man, I'd be willing to bet that the mealies came from other plants in your house. Check this out:

https://urbansproutsstore.com/blogs/spr ... -adversary

Mealies in the crawler stage move from pot to pot, a big problem for nursery growers, although this may not apply to your situation. Believe it or not, ants have been known to bring mealy eggs along for the ride -- if ants come into your house, that could be where your mealies are coming from.

In regards to something I said earlier, what are you thoughts on this?

I'm wondering what order I should do things in. I have to repot all of my plants, so I can also take that opportunity to check for root mealies. But if I were to find that they didn't have any root mealies, and only had foliage mealybugs, should I repot them into fresh potting mix right away, or hold off repotting until I get rid of the foliage mealies to avoid them infecting the new pot and potting mix? (For reference it is the growing season at the moment)

This only matters if I find IPA is a good option, but it's worth asking.

If IPA doesn't harm the plant's skin -- physically remove the stem mealies with a toothpick or tweezers first, spray the stem thoroughly and let the skin dry out second, then repot. Stem mealy eggs that end up in the soil won't survive below the surface, but it's still a good idea to spray around the base of the plant after you repot.

[SpriteFish]

Update!

I tried the spray on two plants that are very obviously covered in farina, and I noticed no effect on the coating. Now I've treated half of my plants, only spraying severe cases (only 2), and manually removing the rest. I will make another update in a few weeks to see how it goes.

I did look at systemic pesticides in nz and the only one I could find must be sprayed on the plant (and is then absorbed through the skin). If IPA turns out to have a negative effect on some but not all of my plants' coatings, wouldn't this pesticide also affect the coating? If the IPA doesn't work or ends up having negative effects not readily apparent, and the nz systemic I found would also have a negative effect, I may need to order one from overseas.