Perhaps you wetted plants too much suddenly. Waiting between spraying is likely better to allow leaves to dry up.

I use 90-99% rubbing alcohol without diluting without problems, but some plants may be more sensitive than others.

I know Dawn (or any dish soap) is often recommended, but IMO dish soap should not be used since it is a detergent. It's purpose is to degrease, and it often cause damage to plants leaves. If using any soaps, it should be vegetable-based soap, not detergent.

There is an Insectcidal soap available already pre-mixed, that is supposedly working on mealy bugs. Also, when spraying, plants should not be in full sun (I do not know if that happened in your case).

Your plants may recover, or may not - it all depends if there is any rot (speculating, based on your statement:..."Now almost all the leaves are falling off of some, heavily dense brown spots"...)

If my plants, I would take off any dead and/or rotting leaves, and prune any damaged branches. I would make sure plants are in soil that drains well (soil that is visible in your photo could be water retaining) and containers should have drainage holes.

I am not sure that simply rinsing your plant (using water) helps with mealy bugs, probably just some very light infestation. They are not so easy to get rid of, and more than water is needed to kill them. Rubbing alcohol or other sprays that are recommended to treat mealy bugs will dissolve their skeleton an kill them. Treatment should be repeated in few days (not few times a day) since eggs will hatch in about 7-10 days. Rinsing with strong stream of water helps more with aphids.

Plants that are fertilized could be more attractive to many bugs - most like new growth that is 'juicy'. Etiolated plants and otherwise stressed plants are often weak, and easier to be attacked. Infected plants are best to be isolated, since mealies will spread easily.

Alcohol or some other sprays could damage leaves; it is best to test first. Overusing anything could be "too much of good thing is no good". But lots of plants will get damaged (shows as scars) by bugs themselves, not by using proper spray.

Soap is phytotoxic and damages leaves. Insecticidal soap is just a specific type of soap which is less likely to do so. Concentration is very important as you have found out. Keeping plants out of direct light after spraying is also important.

I also recommend spraying with timing that coincides with the life cycle of the pest you want to kill. Every few days is too much and normally eggs of any pest are very resilient/tough (Only special things can kill them).

About a week ago, leaves were falling off from some of my succulents due to mealybugs.

I have been spraying 70% rubbing alcohol on my plants, including jade plants and every other plants everyday, without any damages. The infestation is under control now.

I wonder if the damages to your plants were caused by either mealybugs or neem oil. My succulents were damaged by neem oil/detergent spray before.

In addition to alcohol, I soaked the soil with a solution including 1 teaspoon neem oil, 1 teaspoon dish detergent and 1 L water. I won't spray neem on my succulents.

All's well now.

Charline,

Are you sure it's mealy bugs? They don't usually cause leaves to drop if I recall correctly. I've never heard of folks soaking the SOIL. I'd be afraid THAT might cause leaf drop.

Karen, rest assured, some folks do soak the soil. The leaf-drop had happened before I treated the plants.

As I said, my plants are well now.

You will learn with time that some plants will tolerate one spray but not the other.

One I would never mix two chemicals. Dawn will strip the leaves and alcohol will desiccate the leaves. Use them together is probably the problem. Always test the tolerance of the plants outside of direct light for 24-48hours before you decide if it's safe to spray on the whole plant. Alcohol will kill the adults and the crawlers, so there is no need for the dawn soap. Insecticidal soap is used to kill the crawlers, but not the adults. So, you just need the alcohol. Then follow-up with a different treatment in a week or two. Rotating back and forth for months, even after you think they are gone they may still be alive, so don't stop until you have not seen any of them in a three months. If you bug that looks like a gnat, but it's not a gnat, it might be an adult male. Even if you don't see any fuzzies, if the male is alive then you have females alive somewhere as well. Keep at it.

I had tried soap solution before and would definitely use it on Echeveria. I found aeoniums had very bad edema where droplets of the soap solution hence I would never use it on them. You will learn from experience. I experiment a lot with my plants.

I don't grow any Aeonium, but a dilution ratio of 16mL/4L insecticidal soap (1/5th label recommendation) did not damage my Greenovia with one application.

Yes I treated my majesty palm tree with the alcohol solution and now all my leaves are brown and dry I had to pull all the leaves off of 3 branches. I may have to throw it in the trash.

If that were my plant, I would cut off every branch as short as possible and let it send new growth out. I would also do a systemic soak that kills the mealy in the pot and throughout the plant when it gets absorbed. Wash the whole grow area down including pot, and use a fresh mix to start washing off all the roots before using the systemic.

Thank you i will do this in the morng. i hope i can save them

SaSame isissue aand tthey lolook hhorrible i re hope they wwon’t didie

A couple of things I wrote about the practice of using:

Household Detergents/Surfactants

The advice to use solutions of dish soaps/ detergents is short-sighted for a number of reasons. Dawn, Palmolive, Joy, ...... dish soap, as examples, are each and all a multiformity of chemicals, at least eleven of which are phytotoxic. If the above-ground parts of a plant are sprayed thoroughly with even mild detergent solutions such that all surfaces including leaves are covered, the detergent can easily dissolve the protective coating of cuticular wax on the leaves of the plant. Cuticular wax 1) prevent leaves from excessive water loss 2) provide a protective barrier to fungal and bacterial pathogens, which denies them a pathway by which to enter the plant 3) acts as a sunscreen to protect the plant from harmful UV rays 4) acts as a deterrent to many forms of insect herbivory. Some solutions will even dissolve cell membranes, costing cells their viability.

If a detergent solution is used as a soil drench or makes its way into the soil as a consequence of over-spray or run-off, the effect on roots is immediate. Because one of the main function of roots is to absorb water and nutrients dissolved in water, they lack the waxy protective coating that benefits leaves. Detergent solution in contact with root cells can quickly dissolve the lipid membrane surrounding cells, killing the cells and inhibiting water/ nutrient uptake. Hair cells growing as appendages off larger roots do the lion’s share of assimilating water and nutrients, and these very delicate cells would be the first casualty of any detergent in the root zone.

There are widely available insecticidal soaps, designed to be used topically and made mixing potassium with only long chain fatty acids, carefully selected and specifically formulated to be safe for mammals & birds, death on most insects they contact, and most important, safe for plants. If you need something "soapy", it would be much better if you selected a product intended for use on plants than one intended for other purposes; and, it doesn't matter how many growers attest to the fact they've used it for a hundred years with no problems. If 50 million people practice an imprudent measure not recognizing it's imprudent, it's still imprudent.

While a water/ dish soap solution might rid the plant of some insect pest, it can also leave the plant much more vulnerable to the next wave of insect predation, render it more vulnerable to fungal/ bacterial pathogens, increase the risk of damage from solar radiation, limit the plant's ability to remain appropriately hydrated because of increased evaporative water loss.

……………………………………………………………………………..

The killers

Sodium laurel sulfate and sodium laureth sulfate are very effective surfactants used in shampoo and other cleaning products used to remove oily stains and residues. It's effectiveness on oil and grease also extends to the cuticular waxes in the leaf cuticle and periderm of plants. These ingredients are so effective at dissolving oil, grease, and wax they are the primary component of engine degreasers and industrial strength detergents. Let's not forget the perfumes, dyes, and a plethora of other phytotoxic ingredients in shampoos and cleaning products like dishsoaps are a multiformity of phytotoxic (poisonous to plants) ingredients; e.g., Dawn dishsoap contains no less than a dozen phytotoxic ingredients.

Dissolution of cuticular wax in the leaf cuticle (skin) leads to an increase in moisture loss through the cuticle, diminished ability of plants to resist entry of fungal and bacterial pathogens, diminished efficacy of cuticular wax as a barrier to insect herbivory, diminishment of the wax's ability to protect the plant against harmful UV rays, potential injury to the plants photosynthesizing machinery, and an increase in the rate of leaf senescence (aging).

Unfortunately, the logical fallacy (appeal to tradition) that 'having used it for x years without a problem' does not hold water. It's not a question of whether or not the SLS sisters cause damage to plants, rather, it's how bad will the damage be. Too, any discussion about specific surfactants and detergents should include the fact that initial damage often goes undiagnosed, or misdiagnosed, being attributed to some other cause long after the damage was done.

A relatively safe surfactant for use on most but not all plants would be a product based on long-chain fatty acids of potassium, the active ingredient in insecticidal soaps. They are specifically formulated to be as safe as possible for use on plants.

Al