On Dendrobium Leaf? Disease or Pest?

[estación seca]

I don't think mealybugs on plants are a serious enough problem to bring toxic poisons into my house. I think you're going way overboard. From what I can see and read you only have a few. If you keep an alcohol spray bottle with you and regularly spray all the patches you see, the eggs will eventually hatch, you will kill the adults, and with time they will mostly be gone. It's like getting rid of a patch of bad weeds in your garden: It takes persistence for several years, then you can relax.

[c123anderson]

Funny you say that…..

Looking through the photos, I was trying to see if I could pinpoint a culprit or just when then mealybugs arrived.

What I did see what a problem that’s been obvious for a couple of months. Several crawlers are obvious in pictures. At least one or two more mature (though not as big as what I’ve recently killed) mealybugs were obvious. The fuzzy stuff was there for at least a week before I clued in. And I’m no closer to identifying how they came in.

I am very grateful for the tips and thoughts you’ve all provided. It has definitely helped me feel like there is a light at the end of this tunnel and keep a perspective on this situation.

[Dusty Ol' Man]

Originally Posted by c123anderson

And it seems to treat your orchids okay? Little to no phytotoxicity?

I have never seen any ill effects related to insecticides. I have never treated very sensitive plants.

[c123anderson]

Another question on mealybug treatment: what should I be expecting for treatment and outcomes?

I'm just trying to assess if my efforts are working or not. If there are any who've been successful in their process, I'd love to know what to expect.

What I've done:
I have doused and sprayed with rotating insecticide now for two weeks. (Another application in a couple of days.) First application was insecticidal soap the week before that.

What I've observed:
Problem identified three weeks ago. Now looking at orchids mostly clear BUT today identified a V. falcata with what looks like clear signs of it becoming a mealybug buffet.

I've also observed some "stuff" on leaves -- miscellaneous white stuff that I cannot tell if it's residue or mealybug material. I am armed with q-tips and isoprophyl alcohol, which I use to wipe leaves and crevices.

Thank you, everyone, for all your help with this problem. I have really appreciated and absorbed the information everyone has posted.

[estación seca]

Keep a magnifying glass with your plants.

[Roberta]

Just had a thought about mealybug source... Do you by any chance have Cyclamen or Hibiscus around (as house plants)? Those tend to be mealybug (as well as whitefly) magnets.

[c123anderson]

Originally Posted by Roberta

Do you by any chance have Cyclamen or Hibiscus around (as house plants)? Those tend to be mealybug (as well as whitefly) magnets.

Nope. The only non-orchids somewhat nearby are a few African violets.

I have hesitated to repot several orchids. I was hoping the douse would help. Perhaps I’m just seeing in between generations.

---------- Post added at 10:28 PM ---------- Previous post was at 10:05 PM ----------

Ah, okay. Here’s a potential problem: I have a vanilla that’s growing around a pole and it’s lovely and leafy. With white spots around its leaves. It’s also been treated with insecticide, but it’s got loads of hiding spaces.

I wouldn’t suspect it’s any more delicious to mealybugs than my other orchids, but it’s got some great hiding places.

[c123anderson]

Studying the problem a little more, and taking from the advice given here:
1. ES’s thoughts, that mealybugs get in all sorts of places, is true. Even a good first spray may not get them all.
2. The idea of treating for several weeks is because, partially, from #1 and partially that hitting all the generations can be hard with 1 application.
If you can rid an infestation after 1 application, you may share and be hailed the supreme person you are.
3. There’s a variety of ways to treat for this pest, and there’s loads of advice out there. Some of it isn’t so good and can even be harmful to your affected plants. Most of it isn’t bad advice, though, but research your issue.
4. Treatment may cause some damage to your plant. Just because you’ve treated and see a little decline doesn’t mean your plant is a goner. Watch for signs of ill health and, just like treating a sick patient, be sure to nourish your affected plant so it can rebound.
5. Patience is a virtue. If you use a systemic insecticide such as imidacloprid, it’s just gonna take some time for the mealybugs to die out. Develop a plan and stick to it.

I’m just collecting some thoughts for others. Truly it’s been an interesting experience dealing with mealybugs. I hope to come out of this experience wiser.

[c123anderson]

And who may be tired of me posting on this subject?

However, I'd like to share my latest thoughts:
1. I have treated for three weeks (1 week apart) with insecticide. Whatever mealybugs I've found have been few and far between.
2. I have truly appreciated the wisdom of all who've posted. I feel I've learned a lot. I have taken Estación's advice and am using magnification to try to monitor. Wise advice. This has helped me see better what's happening.
3. By not only treating but also nourishing, I am seeing new growth! I've included a picture of my den. Miva Abracadabra bud, but I am seeing some new root growth as well and new shoots.
4. My last treatment will be the Enstar II to try to sterilize whatever mealybugs may be left.
5. What I have done is use not only the pesticides, but spot treat with isoprophyl alcohol and use sticky paper to capture any wanderers/flyers. I caught 1 male mealybug flyer who looked young.

I'm not saying the fight it over, but I am feeling like a corner has been turned.

I have also noticed that the insecticide treatment is harsh on the plants. I hope to evolve to Estación's recommendation of soaking or to treat with insecticide annually or semi-annually as a precaution. Fortunately it seems that all plants seem to be stable if not growing despite the treatments. I had to weigh the chemical treatment versus the damage the mealybugs were doing, and I felt this treatment was going to be the best long-term solution.

I'll continue to post updates, but I have treated as follows:
Week 1: imicloprid douse + cyfluthin spray
Week 2: cyfluthin douse
Week 3: imicloprid douse (using commercial insecticide with an adjuvant.
Week 4: Enstar douse (planned)

Thank you, everyone!

[c123anderson]

Okay, again, another post, but a “happy ending” or, at least, seemingly past the main mealybugs issue.

Attached is a pic of my Bc. Theresa Ricci. After treatments for mealybugs, it had a leaf that didn’t look good. But I’ve watched develop some pretty, new roots. I thought I’d share some happy news. The root tip colors are quite pretty. I got this late 2022, so I’m hoping I might see some blooms from it soon.

The second is a den. moniliforme with its pretty variegated leaf with pink on it.

The third is my den. Jacquelyn Thomas with three new growths!

Partly this is us starting some springtime growth, but, this is why I love spring!

And, this share is a way to give an update and hope but a very big thank you to everyone’s thoughts and shares. It was so helpful. I was also going through some work stress, so everything (stress) seemed amplified. You don’t know how much your kind words here helped in many other ways, too. Thank you.