Last year my plumerias were covered in scale, but I didn't know it was scale until recently. In fact, three plumerias died earlier in the year mysteriously but I think it was a result from scale. I looked online and I barely found info on scale bugs on plumeria stems, most sites had info on scale bugs and leaves. I saw a post on a plumeria facebook group that mentioned scale on plumeria stems and that's how I positively identified them. A few plumerias are covered in them because I went this long without treating them. I wondered why they seemed stunted this year and now I know. I sprayed some neem oil on the stems Monday but I still saw them today. I sprayed again this morning so I'm hoping if I keep spraying with neem they'll go away.
Here's a picture of the culprits
