Mites? Scale? Please help ID the problem.

[Lani]

Hi all,
I believe this is an Australian native cymbidium, it was donated to me in a rather lifeless way so not sure (possibly cymbidium madidum?)
Anyway, I'm having a bug problem. Nasty little spots on the leaves. They don't rub off like scale and the little black dot in the center of some spots seems to be inside the leaf. Any help would be much appreciated!

[Orchid Whisperer]

Fungal disease also known as Phyllosticta or Guignardia: Orchid Diseases
It is treatable: http://www.staugorchidsociety.org/PD...idDiseases.pdf

[Lani]

Thanks for the tip. Would you consider neem to be worth a try or do you think this type of infection needs something stronger? It's really hot and humid here currently so haven't been game to try anything...

[euplusia]

Seems that young weak leaves in the center are more affected. The fungal infection is often secondary following a primal cause.
I do not know the primal cause. Might be standing water droplets, high humidity, insect crawlers, mites.
I would start off by watering only in the morning hours and increase air flow. If the place is too hot and humid, some Cymbidiums might suffer and want to be moved to cooler fresh air. Fungizides are additional.

[Ray]

You might try an alcohol infusion of cinnamon. (Recipe here.)

The alcohol will kill the mites (if that's the issue), and the cinnamaldehyde is a pretty good fungicide.

[Orchid Whisperer]

Originally Posted by Lani

Thanks for the tip. Would you consider neem to be worth a try or do you think this type of infection needs something stronger? It's really hot and humid here currently so haven't been game to try anything...

Hi Lani

I have used neem to stop the spread of this fungus (it is listed on the St. Augustine OS chart for this fungus). Of course, the damage you see will remain, as with any fungicide. If you want something stronger, try the Thiomyl or Cleary's, which are systemic fungicides (both of those may be more difficult to find than neem).

You will note on the chart that not every fungicide works for every fungus. Neem is widely available, and works for this problem. It is also an insecticide and miiticide. It is a good first line solution to a variety of problems.