Update Phalaenopsis with Mealybug Infestation

[monivik]

I thought I would do an update on the following post, which was a couple of months ago: Treatments against Mealybugs

So my two badly affected orchids were the Phalaenopsis Schilleriana (which was practially a baby plant that I had just bought, I say baby because of it's size, it is small so I assume it is a young plant) and the Hieroglyphica.

The Schilleriana lost practically all of it's roots, it was partly my mistake because I didn't have bark to repot in at first and had it in spaghnum moss, and it was just too wet so they all rotted away. Fortunately I used some of that root hormone stuff and it's really been making some roots, there's like 5 of them coming. Also a new leaf.

The Hieroglyphica is a little better, I think because it had more roots to start with. It does indeed seem to have crown rot unfortunately (I think caused by the mealybugs), but nothing to do about that. This little plant is still hanging in there. There's a new root coming as well I can see.

To my horror I saw something just two weeks ago. They still have some sort of bugs on them. What it is I have no idea. I treated them with the "poison" (I mean I really brought in the big guns that time) last summer. Anyway I'm not sure what sort of bugs these are, they don't look like the mealybugs, which were white and "hairy or fluffy". These are microscopic insects. I mean they're hard to spot, if it wasn't for the fact that I was looking really closely I saw something moving around.

I do think they're also affecting the plant, in this case in particular the Scilleriana, because one of the leaves is now turning yellow. I am so disappointed! I thought I got rid of all the bugs.

What I do find strange is that the spray bottle that I used last summer, says use a maximum of 3 times in a year. I've used it 3 times already on these orchids, because I sprayed them I think once a week, three weeks in a row because that is what the instruction read. So does that mean I can't use it anymore on these orchids?

Anyway I don't know if there's any point to keep the Schilleriana? I've tried hard so far but it feels like we're losing the fight. There aren't many leaves left now.

[Leafmite]

If nothing else has worked to get rid of the infestations, try spraying thoroughly with olive oil, letting it sit about six hours, then wash off with dish soap and water.

Many years ago, I brought some new plants into the home and, apparently, they were infested with spidermite, whitefly and aphids. This was in February and I could not use pesticides indoors and I did not have any indoor-friendly oils or soaps. My plants were suffering terribly. I doused every plant in my collection with olive oil (I did not worry about what was under the soil/potting medium), let sit overnight, then washed off all the olive oil (which can be time-consuming if you have many plants). I didn't see any pests for nearly three years after. Olive oil snuffs out everything. I do not like using it because it takes a while to wash every leaf with dish-washing soap and warm water to remove the oil.

When using any treatments, it is important to treat every plant in the collection even if you do not see pests on the plant. Also clean the surface of the table or shelf where you are growing the plants with soapy water. I now sprinkle Food-grade diatomaceous earth on the shelf or table just to make sure that something isn't going to crawl back onto the plants. Good luck!!!

[SouthPark]

Originally Posted by monivik

IAnyway I don't know if there's any point to keep the Schilleriana? I've tried hard so far but it feels like we're losing the fight. There aren't many leaves left now.

That orchid still has a leaf or leaves, so naturally ----- we keep it.

One of my juvenile paphs developed some rot after a mite attack or something. It was down to 1 leaf and maybe one-third of another leaf. But it is making a great comeback after I dealt with whatever was causing that rot.

For my two phals, I just do the usual - maintain nice temperatures, and nice gentle air movement, and nice lighting, and provide adequate amount of water for the roots, and not allowing the roots to drown. And also provide once-a-month weak fertiliser and weak mag-cal.

And those phals are doing really well.

For the media ------ sometimes just have to watch it with the sphagnum etc ...... if the media becomes too wet, then that can have significant negative impact on the roots. There are always exceptions though.

Maybe check the temperature and also check the pH of the media in the pot.

Just attaching pics of my pot set-up. Good drainage pots. Nice gentle air-flow. And my phals have no problem with roots becoming temporarily dry. In fact, my paphs have no problem with it as well.

In the attached pics, some portions of leaves 'appear' to be yellow or even blemished, but they're not actually yellow or blemished. The light shining on those leaves just gives that appearance. The leaves are actually very nice and healthy.

This doesn't mean that I'm after unblemished leaves. The leaves of orchids in the wild and even in the growing area can certainly get blemished ------- circumstantially.

[SouthPark]

monivik - also provide some details maybe ------ about the growing environment - temperatures, humidity, air-movement, how wet the media gets, media temperature etc.

Also - maybe could try pyrethrum type sprays too. Mealybugs.

[monivik]

Well, the Schilleriana since the roots are so short they don't really reach into the medium yet, so I've got it on a bit of spaghnum moss which I spray with water to keep it moist, it does however dry out pretty quickly. So I also give the Schilleriana "baths" every two days, for an hour or two and then take it out.

I also have both a grow light, and a heating pad. I'm not sure how much of the heat of the heating pad is actually reaching the Schilleriana, but the pot is standing on it anyway.

Yeah, I'm concerned though because I think that that leaf turning yellow and super thin and shriveled is caused by whatever insects are still there.

By the way the olive oil, good idea thanks.

I've also got a small bottle of some mixture of neem oil and other oils and stuff that I started using. It says on the bottle to spray every 48 hours.