I had root mealies on a bunch of my plants (not Hoya, mostly cacti and Euphorbias) and imidacloprid worked like a charm. Unfortunately it's no longer available in some states.

The Bonide systemic granules contain imidacloprid. I've been wondering if you could steep them to make a liquid form. If not, applying to the soil should work.

There's a list of products that contain imidacloprid here. But I noted that some of them have changed the formula and eliminated imidacloprid.

This product still has imidaclorprid in it.

Just have to figure out a mix ratio for houseplants.

Thank you both! Based on the Vermont Hoyas recommendation for general pests, I just purchased some of the Bioadvanced Tree and shrub yesterday, which includes imidacloprid. For the plants that I do repot, I was thinking of soaking the roots in a solution of it for 30 minutes, and then watering with it too. Hopefully the ones that I can repot will be okay with just watering with it......

I think that the ones you don't repot will be fine with just watering it in. This is what I did with most of mine (I used Bonide tree & shrub). I have too many plants to repot them all :-)

Just wanted to add, I figured out the concentration from information on a thread over on Cactiguide (a really good thread on root mealies and other pests).

If you have a link for the thread on Cactiguide, I'd be grateful!

I'm so sick of mealy bugs!

Gee, doesn't that make you feel like you should grow all plants in see through cups. You would of never known they were even there if you had not been able to see them and catch them before it was too late.

Popmama, here you go... https://www.cactiguide.com/forum/viewtopic.php?f=24&t=42129

Mike, see through pots would be a great help. I didn't notice a problem with mine until it was pretty advanced, and I did ultimately lose some plants.

Wendy, so did I a couple years back. I lost two huge beautiful Hoya I had for years. I kept loosing leaves, then vines and I knew I was watering correctly. So just for kicks I de potted them to see how the roots were just to find massive cotton balls of those ugly looking things. So gross I didn't even bother to try to kill them. I just threw the plants out(

I did find a mass on my 'black prince' succulent this past summer when I was getting no growth for week's That one I soaked in soapy water for about 20 minutes and have not had a problem since, thank God.

Thank you all for the suggestions. I thought I'd give an update in the hopes of preventing people from being overzealous like I was (duoh). I tried 3 things, based on the scale of infestation, and how precious the plant was: (1) uprooting the cuttings and soaking in insecticide solution. Then repotting in coco coir soaked in insecticide (2) no soak, just repotting in new coco coir with insecticide. (3) No repotting, just watering with insecticide.

I used the Bayer tree and shrub, 1 oz diluted in 1 gallon of water. Soaking the cuttings was a HUGE mistake. I foolishly didn't realize that it also contains fertilizer. About 90% of the cuttings that I soaked got severe fertilizer burn (RIP mathilde). In contrast, only about 5% of the plants that I watered with the systemic turned yellow. It's only been about a week, so hard to tell how well it actually did for treating the mealies. Side note, this insecticide is highly toxic to bees, so be careful where you apply. Learn from my mistakes lol. Shown are a hoya matilde and merrili, which I soaked then repotted, and a Hoya carnosa which I only watered (one of the few to get burned with this approach)

With my Hoya plants, I stick them under soapy water for 20 minutes or more and then let them drain. I never had any pest issues after that, in soil or above. You should try that. Very simple.

I especially do this with every single plant I have left outside all summer before bringing them inside.

Great idea Mike - I will definitely try this come fall. Now do you have a remedy to get rid of squirrels?!

Thanks Mike, will try that in the future! Much simpler and less toxic. My mom mentioned she's tried something like that for her orchids with success for most pests (didn't work for scale I think)

Mike, what kind of soap, what soap water ratio, and do you stick the whole pot and all hoya under the soapy water?

Stupidlazydog, would the watering with Bonide tree and shrub be okay to use with rooted hoya cuttings of only 1-3 leaves? They are all rooted for at least a few months to a year.

Thank you for any information you may provide.

HI, I use castile soap and put about an ounce in a 5 gallon bucket. Fill it with warm water and submerge the entire plant, pot leaves and all.

I also just started using the Bonide they speak of and I hope it works .

I only use see thru cups for hoyas for this very reason, orchid pots work great! all sizes on amazon. I even buy soft see thru dixie cups for tiny cuttings, 2 oz size, I will never go back to colored pots again for hoyas, anyways :)