Mystery Problem with Bellina 'Ponkan'. Need Help.

[realoldbeachbum]

This tiny plant has been in my care for one year. About 6 months ago, tiny silver pitted indentations began appearing on both under & tops of leaves. I treated it twice with Bayer 3in1 Rose & Flower Spray (Tau-fluvalinate & Tebuconazole) thinking it was thrip damage, although no thrip were seen even with a magnifying glass.

The treatment seemed to slow expansion of the silver pitted areas. Now, however, a dense pitted area on one leaf has turned brown on the leaf surface. The brown area does not appear on the underside of the leaf -- only the pits. More worrisome, though, is a brown area in the crown.

It is in seedling mix with a layer of spagh and is watered every 10 days or so with weak K-Lite. Once a month it is drenched with Quantum Total & Kelp Max – same treatment as my other phals.

It was a TINY plantlet when I received it one year ago. I was not sure it would make it from the beginning, but it has hung on. (Yes, it is in a plastic wine glass – with good drainage.) Roots are bright green and healthy.

Environment: Inside under grow lights 11 hours per day, along with my other phals. Temps are between 70 F to 90F and humidity is between 50&70% with slow fan during heat of the day.

Any idea what might be the problem? Treatment?

Thanks so very much, ROBB

Phal bellina 'Ponkan' 05212022 — Postimages

[Leafmite]

This mystery illness has come up in the past and in my orchid society. Some say it might be a type of mite that cannot be seen. Some say that it can be cured by spraying with alcohol (or brown listerine) every day. No idea. Hope someone else can help.

[estación seca]

It sure looks like tiny mealy bugs, scale or mites to me. Can you see any with a strong magnifying glass?

Take it to your county agricultural extension office, or to a university with a biology department. It would be good for somebody to scrape off some of that and look at it under a microscope.

I don't use neurotoxins on my plants for bugs because they develop resistance so rapidly. I find rubbing alcohol or soap spray works much better.

I don't know what that is, but I would unpot it completely, let the roots get almost dry, then submerge the entire plant in slightly soapy water for 8 hours. That will drown almost any bugs plus eggs.

Then I would use a cotton swab gently to rub off anything I could, and a water spray into the crevices to dislodge anything I could. Do you have a Water Pik for your teeth? They also work well on bugs in crevices - run slightly soapy water through it.

[Ray]

“Mites” is what first jumped into my mind. I would try another round of 3 treatments of the 3-in-1 product.

Phal. bellina is one of those “hot” growers, so you might try upping the temperature and humidity, as well. Read ES’ summary of Norman Fang’s talk.

[realoldbeachbum]

Thanks, es. I will try the soapy water treatment. Appreciate your input very much!

---------- Post added at 10:40 AM ---------- Previous post was at 10:38 AM ----------

Hummm. Mites? I can't see any with magnifying glass.

Is the brown in crown worrisome?

Thanks, ROBB

[realoldbeachbum]

Originally Posted by Ray

“Mites” is what first jumped into my mind. I would try another round of 3 treatments of the 3-in-1 product.

I found the source of the silver streaking (turning into brown patches) on my Phal bellinas: False Spider Mites - sometimes called Flat Mites (yes, purchased a microscope for proper identification $$$).

Does anyone have experience with these rascals? They are slowly killing my bellina collection and have now spread to Paphs!

I tried water emersion from ES, but drowned two bellinas in the process -- bad orchid mom here. Also tried BioAdvanced 3in1 with no success.

[Dusty Ol' Man]

I hate to keep pushing the big guns, but if you haven't tried the malathion route, now would be a great time. It won't hurt you or your mammals. The state of California used to do aerial spraying with it to kill Mediterranean fruitful infestations back in the 80s. I've used it with great success. That said, I have not had to deal with this particular critter.

[Roberta]

If mites, use a miticide. (There's a little in BioAdvanced but it's mostly insecticide) I have used Bifentrhrin - it is used for termites and more reasonably priced than most miticides. Remember, mites are not insects, they are arachnids so likely insecticides will be of no use against them. "smothering" treatments like Neem oil may work but for a persistent infestation, don't mess around.

[realoldbeachbum]

Dusty - Is malathion OK for basement grow room with outside entrance only? No house entrance, but could it come through the AC duct work?

---------- Post added at 05:50 PM ---------- Previous post was at 05:46 PM ----------

Thanks, Roberta. I will check out Bifentrhrin. Is it safe for basement grow room -- like, is it harmful if it gets into the AC duct work, entering our living space?

[Roberta]

Both Bifenthrin and Malathion are rated for spider mites. For either one, apply surgically... just on the plants. You're treating a small area, so exposure is minimized even if some gets out into living areas. Toxicity is fairly low for either. In the case of Malathion, you'd want to minimize the quantity in the air anyway... the stuff stinks to high heaven. Bifenthrin not so bad.