Spider mites!!!!
 

I have about 35 catasetinae, all in my indoor greenhouse (a bedroom). At the very end of last season, when about 25% of them still had leaves I had a spider mite outbreak. Being late in the season I simply removed all leaves, drenched with alcohol, and repotted. I haven't seen any since and all are in varying degrees of new growth, some quite large.

Except for one plant... Two weeks ago I detected some brown spots that looked a little like spider mite damage, I drenched with alcohol and moved it to the cattleya section to keep it away from my other soft leafed orchids. I watched it like a hawk for the last two weeks and didn't see anything. This morning I saw one.

I now have that plant on a separate floor. My other catasetinae still look pristine.

a. How to best treat the affected plant?
b. Preventative treatment for the others?

Thanks in advance!

Were it mine, I'd just spray it with alcohol and keep an eye on it.

Thanks for your message and sanity check (I was about to break out the Imidacloprid and start watering early).

Would you spray all of them or just the quarantined plant?

since its inbetween seasons, a good rinse with some isopropyl and soap would be easy to treat everything you think might be infected (or even the entire collection). you can never really get rid of spider mites 100% and catasetinae leaves are like crack for them. just my $0.02

I would spray the one where you found them, then start keeping an eagle eye on ALL of them. For me, I've never been known to treat anything that I wasn't positive already had an issue. But I have been known to look over a plant with a magnifying glass. :blushing:

Just realized a magnifying glass would be a really nice thing to have around the grow room!

I do not envy you :).

I do not believe you will be able to get rid of the mites without using miticides.Best I can recommend is Abameci(t)n.
You should also check other plants.It is NEVER only one plant !!!!!

Looki here :-https://www.staugorchidsociety.org/PDF/SelectedMiticidesforOrnamentalPlants-UFIFAS.pdf

Imidacloprid doesn't work on mites. You need a miticide.

Spider mites are microscopic organisms. I believe there's one specie that can be seen with a neked eye but in general they are too small for the human eye to see them. A magnifying glass of at least x10 is enough to notice them.

Another thing is, one can't get rid of mites. All the treatments are aimed in controlling their population, preventing their number to increase to a level that can be dangerous. But once one of your plants have them, assume that all of them are infestated.

Prepare a solution of 3 tablespoons of washdish soap per gallon of water + 5% alcohol. Spray the whole plant everywhere, medium included but especially on the under side of the leaves.
Wait 10 minutes and spray heavily and furiously water evreywhere on the plant (but without damaging it, an hand spray bpttle is good for it, you can spray directly and more closely the different areas of the plant.

Then repeat this "treatment" every 5 to 7 days for a month.

Then you'll have their population controlled. Ideally you should do it for all the plants you have, which is why spider mites are a #@!!.

Thank you, this helps me understand the containment strategy. I have also moved one of my humidifiers next to the catasetinae as I read spider mites prefer less humid conditions. The infected plant is in the basement.

The species I have is visible (thanks Lasik surgery) I know because I had them at the end of last season. 6 of my catasetums are quite far along with new growth and the leaves are perfect.

I am going to take your advice and spray my whole plant room, plenty of time these days on lockdown and I'm running out of things to do anyway!

Can you clarify what you mean by 5% alcohol?
Most of my catasetinae are still not being watered, so I still soak the media?

Thanks for the support!