Scale on Desert Rose

I have these little things on my Desert Rose. I wash them off and they reappear in a day or so. Can I spray with Neem Oil weekly?

I am not sure about weekly. Read the label for directions for it will take in account their life cycle so you get them in all stages.. Usually insecticides tell you plants cannot tolerate it. I bet adeniums do fine with it.

Years past I have used neem, alcohol, neem mixed with insecticide soap. The scale always come back.

I finally had a row of white oleanders, each were covered in scale. Totally covered. 2 were about dead. So I bought Bayer Tree & Shrub systemic. It was a gift from God. I mixed it with water per instructions and then poured it round the base of the trees. It lasts 1 year!!! No spraying which always ended with more on me than the insects. And it worked with 1 treatment. The only drawback was the dead scale didnot drop off. But they were so dead.

I also used it on a huge staghorn which had scale in the deep recesses of those leaves and in between years of shields. 1 treatment with Bayer and they were dead.

Good luck!!

Would that systemic also work for mealy bugs?

Would that systemic also work for mealy bugs?

I am pretty sure it does. It kills sucking insects. I recall using it on my clivia in small doses I guessed at, where the mealies would get down into the fan of leaves where I could not even reach. The problem being, I recall you were not supposed to use it on houseplants which some of my more prized ones were. So I treated them outside and was so careful with the water the spilled out the bottom each watering. Though from what I have read the active ingredient Imidacloprid is low on the toxicity to humans, I still try to use insecticides only when desperate. I could not grow clivia in large numbers without mealie control.

I just checked online and Merit (Imidacloprid) the active ingredient is effective -
"Imidacloprid was found to be more effective than methidathion on all mealybug developmental stages. In addition to its outstanding, up to 100% efficiency, imidacloprid provided an interesting long-term control of mealybugs."

"Toxicity: Imidacloprid has a relatively low toxicity to humans. It is highly toxic to bees if used as a foliar application when bees are foraging. The toxicity to fish is moderate to low. Seeds treated with Imidacloprid can be toxic to birds especially the house sparrow. It is moderately toxic to earthworms."

Bayer Tree and Shrub comes in several ways. I used the liquid form applied to the soil around the base of the plant, with no fertilizer added. I felt I had so much more control than I had with spray. Lots of their products have Imidacloprid.