On Dendrobium Leaf? Disease or Pest?

[Dusty Ol' Man]

While I have not had to fight mealies (yet) I have dealt with other insect pests. My go to is malathion. I mix it per label instructions and put some in a spray bottle. Then I spray every surface of the plant until it is running off. I also drench the medium. Three treatments at one week intervals should eliminate anything living on your plant. (The stuff stinks so do it outside.)

[c123anderson]

Originally Posted by Roberta

Did you check out the YouTube video from isurus79, here's the link to his post:How to use hydrogen peroxide on orchids - Orchid Board - Most Complete Orchid Forum on the web !

Thank you! I had seen the link then couldn't navigate back to it.

Originally Posted by Roberta

First, Isopropyl alcohol will be quite useless as a drench, don't know if it will harmful but certainly not going to solve your problem.

What I've seen is some folks mention "sprinkling" isoprophyl alcohol upon seeing mealybugs. My initial reaction is skepticism that this is an effective method.

Originally Posted by Roberta

It is probably time to stop messing around with "organic" half measures and break out some bigger guns.

Done. To be honest with you, I have extremely mixed feelings on the "organic" half measures. The items I bought at the local Lowe's upon identification were labeled "organic" and, well, seemed to be what was recommended in my various Googling "how tos".

What I've learned in the various "how tos" out there is that there is a theme of organic - organic - organic. There's very little information on what to do when you have an infestation. The information, too, is somewhat generic and seems to repeat itself, including information that's really poor advice. Living in an agricultural area with not new plants: once you see one, you've not see all of them. Assume there are many more.

Originally Posted by Roberta

Bayer's BioAdvanced has some systemic properties. You likely can still get imidacloprid....

I actually have a neighbor who's got his PhD in Etymology. What a resource he is! He currently works with crop development and protection from pests. He specifically recommended imidacloprid. As he described it, it's a systemic insecticide, where it will travel through the roots and leaves and travels through the plant tissues. (Note: it is ineffective on spider mites.)

Although he gave me some concentrated pesticide to apply, I was able to find some in the BioAdvanced line. Their "Concentrate Insect Killer" contains both imidacloprid and beta cyfluthrin (which is a contact insecticide). I used that as a douse mixing in appropriate amounts with water.

Note that imidacloprid is the insecticide used on topic flea/tick treatments for animals. Although this makes me feel a little safer with using it, I still use nitrile gloves when applying and keep good air flow.

Originally Posted by Roberta

The schedule... whatever you use, you need to do it weekly for 3 or 4 weeks at least. Ideally, you have more than one pesticide, with different mechanisms, to avoid resistance, rotating the different products.

I have several different insecticides and am rotating. I decided to give plants a rest for a couple of days, but, Roberta, you may have talked me into applying tomorrow morning. I pulled a mealybug off a den. this morning and rubbed isoprophyl alcohol over it.

I'm definitely discouraged after 16 days of treatment. I have found Enstar and am getting some, in the hopes that I can get the pest situation under control.

Originally Posted by KatieM

I am following this.

So I'm including some of what I've found for you, Katie. Although I want to treat my orchids well, I am disappointed and disillusioned with "organic" answers to this pest problem.

A friend/colleague of mine, whose husband teaches in our local college's agricultural department, has an infestation of mealybugs on her succulents, she said. I told her what I had used and had asked her about neem oil. Her response was that many of the organics, in order to be effective or to have similar efficacy as the chemical pesticides, must be used in such a concentration that resulting byproducts cause more damage than the chemical pesticides do.

That being said, I think there's a place for organic pest control, but if I'm not interested in merely providing an expensive meal for mealybugs or willing to throw away my orchids. I feel I'm at a point where "it's them or me".

If my questions or the advice others provide here can be helpful, please lurk. But I've pulled out the big and now bigger guns. They're likely in my phal. potting bark and have taken some of the joy out of my orchids.

Originally Posted by KatieM

I'll be lurking to see what others recommend and sending good vibes to you for the death of all things mealy!

Lurk away! Death to all mealys!

[Roberta]

IPA is fine for killing a mealybug or two It is very satisfying to watch that waxy fuzzy white coating dissolve leaving the naked bug that can then be dispatched. Certainly not up to the task of dealing with an infestation. It's just for the occasional onsey-twosies that might show up on a phal, etc.

Yes, definitely time for the stronger measures. If you use imidacloprid one week, maybe enstar the next , then back to imidacloprid you have a fighting chance.

[estación seca]

I don't find mealy bugs to be nearly as frightening as most other people seem to. I have not used pesticides for mealybugs nor scale in many years, and I have never used pesticides for spider mites. I watch my plants closely. When I see bugs I treat quickly. I usually use 70% alcohol spray for mealy bugs or scale, alcohol or dish detergent in water for spider mites. If there is a repeat mealy bug or scale problem, I submerge the plant completely, pot and all, in slightly soapy water for 4-8 hours. This kills the mealy bugs or scale. There may be leaf damage with soaking from a dense infestation, with water entering the plant through many tiny bite marks. I soak those plants for 2-4 hours.

[Roberta]

Prevention (and early treatment when a problem appears) are certainly best. Alas, it sounds like for the OP, that ship has sailed. I have been fortunate enough to have not had any problems this bad. But clearly other people have... there comes a a point where one has to get the problem knocked down to get to the stage where prevention/maintenance become options.

[estación seca]

You should see some of the cacti I've salvaged from people who thought they were supposed to be completely white and fuzzy.

[Roberta]

Originally Posted by estación seca

You should see some of the cacti I've salvaged from people who thought they were supposed to be completely white and fuzzy.

Ick!

[c123anderson]

Originally Posted by Dusty Ol' Man

My go to is malathion. I mix it per label instructions and put some in a spray bottle. Then I spray every surface of the plant until it is running off. I also drench the medium. Three treatments at one week intervals should eliminate anything living on your plant. (The stuff stinks so do it outside.)

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

I have a couple of plants, notably a rhyncholaeliocattleya that, although it came to be with an injured leaf, the plant is looking worse for the wear after treatment. I fear/wonder if I have mealys living and feasting in the media.

---------- Post added at 06:05 PM ---------- Previous post was at 04:51 PM ----------

Originally Posted by Roberta

Prevention (and early treatment when a problem appears) are certainly best. Alas, it sounds like for the OP, that ship has sailed. I have been fortunate enough to have not had any problems this bad. But clearly other people have... there comes a a point where one has to get the problem knocked down to get to the stage where prevention/maintenance become options.

Yes, unfortunately, I didn’t recognize the problem until it was a serious problem. This came from my focus on one area and not on the whole plant. Also, too, I observed some decline, but didn’t readily identify it until I posted here.

estación seca, I like your soaking method, and I believe I can get my plants to a point where this is feasible. Are there orchids you do not recommend for this soapy soaking treatment?

[estación seca]

Don't soak think-leafed or tiny or heavily infested things for more than a few hours. Don't soak unless you can dry them quickly and keep them fairly warm while they're wet. I wouldn't want to soak Phals when it's 62 degrees and the tap water makes you shiver.

And remember mealy bugs crawl away from plants to lay eggs. Be always on guard and spot spray when you see just a few.

[c123anderson]

Hi all. Just an update .... really my observations. For any who stumble across this or are otherwise following with their own mealybug issues, here's what I've done and what I've observed.

Every orchid got a soak and spray down this morning with cyflurthin (last week was beta cyfluthrin and imidacloprid).

I am keeping records of when and what I apply. I am keeping a photojournal of orchids and progress, at least until I feel I'm better at observing. If you are reading this and do not otherwise keep a journal, I have found this to be invaluable. I keep a journal of watering schedules, noting when I fertilize. I take pictures of my orchids to help me document changes (usually positive, but, lately, negative).

A few days ago most got a little fertilizer (those who were due for watering). Throughout I have interspersed water with kelp solution (will be switching to the kelpmax). I had not thought about the damage that the insecticide may do to the plants. The fertilizer and kelp/probiotics will, hopefully, help all plants continue to be strong thoughout treatment and withstand infestation.

Speaking of infestation, so far I have documented a few flying what-nots. (I don't have a microscope, but I feel confident that they're male mealybugs.) But I have only seen/killed a few females. That's not to say I haven't seen the white fuzzy stuff around, but I haven't seen a lot. What I mean by that is that I have seen no more than about 10 fuzzy spots. I had one plant that was in poor health, poor roots, and it already had about three fuzzy patches under its leaves. After a short funeral, it was in the trash outside. This was my "infested" plant.

So, here's my question for anyone who's got a thought: with what little I saw, do I have an "infestation" or do I have just a "problem"?

Thinking: in Texas, the mantra as a kid was, "if you see one cockroach, there's many more you're not seeing." Does this thinking apply with the mealybugs? I am assuming yes.

On the one plant where I first spotted a mealybug (Jan 20), I found a second one about the same size 17 days later (Feb 6). Mom and daughter or is this three generations?

Fri, Jan. 20: first spotted
Sat, Jan. 21: insecticidal soap spray (Potassium Salts of Fatty Acids)/insecticide douse (tebuconazole, tau-fluvalinate)
Sat, Jan 28: insecticide douse + spray (beta cyfluthrin and imidacloprid)
Tue, Feb 7: insecticide douse + spray (cyfluthrin)

Note: I found the latest mealybug Feb 6; I sprayed/doused with the tebuconazole, tau-fluvalinate after seeing the first one on Jan 20. Is it fair to assume that the Jan 21 pesticide did nothing? It's not like I had one then POOF a second one appeared almost 3 weeks later.

Also note: I am using the Lowe's/home improvement box store off-the-shelf products, and I'm mixing to label strength. Having some farm stores/ranch stores nearby, I may have access to some stronger mixes, but I am going weaker, first, since I'm applying to orchids.

And, a final note: the value of keeping a photojournal is that I am looking at how long my orchids have had mealybugs. I can spot crawlers two months ago on the plant where I first noticed "the problem". The value is tracking progress and seeing now what I did not see before. It's definitely helping me learn!