I got rid of them on my orchids once and for all by using a systemic. Not sure if this would work or be safe for other plants, but no issues with orchids. I think I used a bayer rose systemic. I made the solution fairly dilute, and dipped the entire plant, pot and all into a bucket, let it soak into all the substrate and then let it drip dry. Mine were all indoors, so I didn't worry about bees. I hated to do this, as I hate using poisons, but I battled them for years. I also carefully cleaned the shelves they were on, and actually found some little "clumps" of mealy bugs in the crevices of the wire rack I was using. Those little creeps are awful. Good luck.

The best way is to never let them into your collection. So quarantine your plants when you first get the them, repot into fresh soil/mix once quarantine is over, and be proactive:).

I personally use rubbing alcohol when I find them. Beneficial bugs help like little spiders and lady bugs.

Keeping your plants clean of detritus helps too. It allows for better airflow and makes it easier for the bigger beneficial bugs to go through and clean up your plants.

Then there’s always systemic, but I rarely use this because the systematic kills the bad bugs, but also the good bugs. So if I do use it I don‘t let that plant flower, but I keep my plants outside where there are bees and hummingbirds. If you keep your plants inside then I wouldn’t worry too much about systemics.

I had a terrible outbreak of mealybug this past summer. I got rid of them.

Week 1;

I would spray each plant with alcohol (Caution not all plants can tolerate alcohol). As soon as the alcohol dried, I sprayed with neem oil. (Caution do not put your plant back in any direct sun for a day or two after using neem. Also, some plants are suffocated by neem oil.) I diluted the neem with water and insecticidal soap as the emulsifier. (Caution not all plants can tolerate insecticidal soap). That was week one.

Week 2;

I sprayed all my plants with Triazicide (Gamma-Cyhalothrin) The stronger of the two dilutions. I would spray the soil as well as the plant.

Week 3;

Repeat week 1.

Week 4;

Repeat week 2

I did this for 2 months.

After that I would spray only monthly.

I did all of this indoors, I never spray insecticides outdoors.

I did not use systemics. Studies have showed that because mealybug often feed on the thicker part of the plant they never penetrate the phloem/vascular layer. If they do not break the vessels they do not eat the systemic.

Mealy bug is inevitable no matter how clean you keep them. If you have plants you will have bugs at one point or another for most. They come in through screen windows, open windows and doors, they hitch a ride on your clothes if shopping near other plants, from leaving them outside, on plants bought and on plants handed down.

Someone said to be pro active and that can't be understated. I treat all mine all of the time even if I can't see them and I constanly inspect them No matter how much work I put into preventlng them, they still show up somehow. The key is to keep them under control. Once they have gotten into the root zone, either throw them out, wash all the mix off and root and spray, or pray they have not spread. The root ones are the worst.

I agree Meyermike. No matter how well you care for your plants, infestations will occur. They may be more likely on sick plants but healthy ones also get hit. The same species seem to attract them in my collection eg Ferocactus robustus, Sulcorebutia arenacea, Astrophytum myriostigma to name a few.

I use a systemic insecticide called Suscon G which are granules mixed in with my potting mixture when repotting. I have not had a case of root mealies for over 10 years, even when the plant has not been repotted for many years. Mealies on the plant body are another matter and are dealt with as needed with a contact insecticide. With a large collection, it is impractical to seek them out and manually deal to them eg by squashing them or paint brush dipped in alcohol.

S g funny you should say that. For anyone that does not want to toss their plants even though the roots are infested either has to soak the whole plant in an alchohol water like mixture like I have done or use systemics. Especially with a huge collection.

Funny you should name certain plants. I can tell you that no matter what you do and how clean you keep certain ones, they will get bugs no matter what. To name a few, which is the reason why I try not to grow them, plumeria, desert roses, palm trees, banana trees, croton, purple passion, hybiscus, black prince echeveria, and most annuals held over winter just to name a few.