What happened to this violacea leaf?

[katrina]

It doesn't look like typical mite damage to me. I'm not seeing the usual speck/dot that I see when I've had mite damage show up. Usually I see a teeny tiny dot in the middle of the area and that will look like a little yellow spot inside the bigger spots. If that makes sense.

My guess would be mesophyll cell collapse and that is caused by not only water temp issues but can be caused by air temp issues. It can be hard to identify what caused it or when because most of the time the damage is done weeks prior to it actually showing up.

You mention that you had it on a heat mat for awhile and then not...perhaps the overall temps changes were too drastic in a short period and this is the result.

If you wiped the leaves w/a white paper towel and came away w/no red streaks then you don't have mites. The pics of the insect you showed *might* be thrips (hard to tell, really) but thrips don't typically do damage to leaves...they eat the buds...so I think they are unrelated to your problem. I've had some seedling phals do this and once it's there, it's there. Your new leaf looks good so I would just try to keep the temps consistent and watch the temp of the water you're using.

IME, vios can be a bit touchy w/water and air temps. I grow mine down to 58-60 in the winter but I know it would be happier at much warmer temps. This past winter, for no apparent reason, it developed some of the same issues your pics show and then it also developed a black rot issue in the collar. I didn't change anything about what I was doing for it as I've done for the past at least 4 yrs...and still it happened. At least I didn't think I did but, clearly, something happened. I ended up losing the crown and I'm now hoping for a basal keiki at some point. I would pitch it, if not for the fact that it's the most beautiful deep purple vio I've ever seen. After much thinking on it, I chalked it up to my tap water being too cold for a period...even though I didn't think it was any colder than I usually water with. Like I said, w/the mesophyll situation the damage is usually done weeks before the problem shows so it can be really hard to pin it down.

Now, with all of that said, I guess there would be some insect issue that I've never experienced but if you're not finding anything when you wipe then I'm led to believe it's not insects. Plus, insects typically go for the young, tender leaves first so I would expect to see damage on that newest leaf if it were mites.

Just my 2 cents.

[No-Pro-mwa]

What Katrina say's make sense to me. I just wanted to add that last year I had what I think were spring tails in a pot I had gotten at an orchid nursery. I just mixed up some neem oil and sprayed the top of the pot. It seemed to do the trick as I haven't seen the little critters sense. I have also been known to just water with it as well.

I don't know if it has any systemic ability but some one told me that once. I love neem oil and have had good luck in using it. And that's my 2 cents.

[PaphLover]

katrina,

Thanks for your informative post. It is possible that the plant was exposed to cold previous to my getting it in November. I've been back to that nursery and touched other phal leaves they've had that were cold to the touch and a chartreuse green (Mine was a similar colour when I bought it. The owner said it was due to too much light.) She admitted they'd been in a cold greenhouse and were just brought in to the warmer one.

I'm not sure if that is too long ago to be the cause of this now, but I did read that with mesophyll cell collapse the symptoms often don't show up until the plant is in/ gets stressed by warmer temps (which would be the heat mat/ T5H0 light situation).

I'm careful to water with room temp water, although, in writing about it now and thinking... I wonder if that might have affected the plant. If it's on a heat mat at 10-20 degrees higher than ambient temp and you water with room temp water, would that shock the plant?

I've removed the violacea/bellina from its old media and soaked it in water overnight (I read this could eradicate critters). I trimmed off any dead roots and it still had a mass of lovely green ones. They are less thick than other phals and a lot of them were flattened and had brown lines running width-wise across them. (If this provides any clues.) I'll repot this morning.

Any thoughts on whether to stick with sphagnum or repot in something else? I have lava rock, LECA, bark, I could mount it.

Thank you all very much for your knowledge and feedback.

[katrina]

I can't say whether or not watering w/water 20 degrees cooler would do this but in the summer my hose water is definitely that much cooler and I've never had this happen then so I'm inclined to say that likely isn't the sole cause. Maybe it's just a combo of things...some of which started before you even had that plant. The new leaf looks really good so I would guess that your culture is good now or that one would be showing signs too.

As to the media...I don't like sphag for potted phals but that's because I grow outside part of the year. Just stick with what's been working for you with your other phals.