The past couple weeks, several customers have brought in pieces of Ruellia (Mexican Petunia) with worrisome white splotches on the leaves. At first glance, it could appear to be a fungal issue or even a chemical or paint residue, but that’s not it… Here’s what to look for and our recommendation for treatment.
The white funk is actually a type of growth distortion called erineum caused by tiny mites called eriophyid mites (Acalitus ruelliae). So that means fungicides would be a waste of time and money to solve this issue. We recommend treating organically with All-Seasons Oil Spray (a horticultural oil). Repeat the treatment every 5 to 7 days for a total of 3 treatments, wait until Spring, then cut the plants down to ground level. This should kill the mites and the plants should grow back out and look beautiful again. Another approach would be to use organic Spinosad soap or Bee Safe 3-in-1 Spray to treat the mites, then cut to ground level in Spring and wait for clean regrowth.
-DeAnna
Samuel Bolton says
Not actually Acalitus ruellia. That mite is not present in Florida. All cases of erinea on Ruellia in Florida are instead attributable to Acalitus simplex.
Samuel Bolton says
My mistake I thought this nursery was based in Florida for some reason. I would love to see specimens of eriophyoids from Texas on Ruellia to confirm the presence of A. ruellia.
Chelsea says
I’ve got photos of mine, I’m in Texas. Where would you like me to send them
In my case my coleus became infected first and started spreading the love. Im fixin to throw them away, pots and all. Is this an over reaction? I have somewhere close to 50 or so plants and I love them all. I’ve accepted sacrificing these few to save the rest If necessary ????