HELP! Fungus in my phalaenopsis?
 

Hello,

I have two phalaenopsis that present some irregular spots in their leaves. One of the orchis has these spots since i bought it (two years ago), and they are getting worse. The other one started to present the infection 6 monts ago (I have the orchid since 2019).

Do you know what kind of infection could be? Can you recomend some treatment?

Thanks a lot!!

I don't think it is fungus. Pest such as spider mites maybe - especially if it is spreading to another plant. They are microcopically tiny so yo won't see them, but they suck the juices out of leaves. Especially look at the underside of the leaves - if they have a "silvery" appearance, for sure. Or wipe the underside of the leaf with a tissue... red streaks on the tissue would be another indication.

Specific treatments require first knowing what you are treating. But you could spray the leaves (top and bottom) with 70% isopropyl alcohol for a start, and repeat in a week. That will greatly reduce a pest infestation. (The repetition is important, to kill succeeding generations... you will never get them all)

I checked several times and I did not see any spider mite. In fact, I've treated for spider mites one plant that is outside, but I haven't seen anything in these particular plants.

As you can see, the flowers are still perfect. The orchid has had these flowers for 3 months. Spider mites can distroy flowers, no?

What do you think?

Thanks!!

Spider mites don't necessarily destroy flowers, other pests to that. Perhaps another member has some ideas...

In my experience, spider mites do not attack thick leaves such as Phals (or at least, it's a lot more difficult for them).
As a side note, spider mites are everywhere. This means they're vistually impossible to erradicate. But you can control their population to a minimum.
About your plant, it seems to be some kind of insect damage. Which one, I don't know.

I know some people on the FlytrapCare Forum swear by Captain Jack's Insecticidal Super Soap as a starting treatment for pests, one being spider mites.

https://captainjacks.com/product/ins...uper-soap-rtu/

You can get it at most hardware/gardening stores. You can squirt some on a paper towel and wipe the tops and bottoms of the leaves of your phal.

I'm not one of the super experienced people here, so I'd listen to others here over my advice, but that's what I would do as a start.

Note that the OP is not in the US so likely will not have the same products available in their local store. The concept of insecticidal soap is a good one - that, or any soap solution, kills insect and arachnid pests by clogging the pores of their body and basically drowning them. Like any "contact" remedy, it only affects the ones that it hits, doesn't get them all so needs frequent repeating. And also only kills adults, not eggs.

Ah, so would a full soak in something besides soapy water work?

I've tried using the cinnamon leaf oil I got from Ray for other things, and it seems like a lot of bugs don't like it. Don't know if it would do anything to eggs or larvae, though. I know a popular solution lately where I live for mosquito prevention is something that contains lemon oil from lemon peel, and something else that's "natural" or plant-based.

I mention those as I don't know what the Spanish government or even the EU says you can use for insect control, but I know the more "natural"/plant-based solutions are favored/not as controlled.

Before prescribing a treatment, it is really necessary to gain more understanding of what is causing the problem.

---------- Post added at 12:41 PM ---------- Previous post was at 12:26 PM ----------

One possible pest that comes to mind, that could produce those small "scars" on the top of the leaves... bush snails. If you pour water through the pot (get it very wet) they may show themselves - look like little "flying saucers", size only a few milimeters. If you see those, search the Forum for notes on using coffee to kill them. (Look for posts by rbarata on the subject)