# Scale



## justagirlart (Jul 12, 2019)

What can be used to kill scale on Phrags?


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## Ray (Jul 12, 2019)

The best product will be a systemic, since the adults are quite well protected from topical treatments by their shells, while they suck the juices out of the plant.

My preference is acephate.


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## tomkalina (Jul 12, 2019)

FYI - Acephate is highly toxic to bees.


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## CarlG (Jul 12, 2019)

If you only have a few plants, repeated scrubbing with a soft brush and soapy water may do the job. If you have a substantial collection, acephate is better. Careful where you spray it (and it stinks, too).


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## abax (Jul 12, 2019)

orthene, which is a drench, is very effective on
scale. However, it is destructive to insects in
general. Unless you have a contained area like
a greenhouse, don't use it. Yeah, it stinks.


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## NYEric (Jul 29, 2019)

If its a few plants, use 91% alcohol on a paper towel. If its many you need a spray.
We use a solution of Dr. Bronner's peppermint soap, Neem Oil, alcohol, water, and for the kicker Merit 75.
BTW, we have about 200 Phrags and know a little about growing them.


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## justagirlart (Aug 17, 2019)

Thank you. I am jealous. All I have is a starter kit of 20. Love them. They are my favorite orchid.


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## h_mossy (Sep 12, 2019)

Does a horticultural grade of oil work on scale, too? A local grower mentioned this recently, but did not say if it would work on paphs / phrags.


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## likespaphs (Sep 12, 2019)

h_mossy said:


> Does a horticultural grade of oil work on scale, too? A local grower mentioned this recently, but did not say if it would work on paphs / phrags.



yes, but as it is a suffocant, it is necessary to get appropriate coverage
sometimes the crawlers are down in the leaves and not easy to get


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## Jim734 (Sep 13, 2019)

likespaphs said:


> yes, but as it is a suffocant, it is necessary to get appropriate coverage
> sometimes the crawlers are down in the leaves and not easy to get


I would caution you to try out whatever you use on only one or two plants to see if there is any adverse reaction to the plant. On one occasion I used Safer Soap to get rid of aphids on an Epidendrumm and the whole plant just wilted and died - it was a softer-leaved Epi. Also the temperature should be not be too warm if you use oil spray. Softer-leaved plants seem to be more sensitive.


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## Ray (Sep 13, 2019)

I used to be a big proponent of oils, but have backed off because the "bang" is minimal and the "buck" is quickly consumed by the damage they can do to the plants.

Consider Azamax - it is a concentrated form of azadirachtin, the active ingredient in neem oil, without the oil. It is a contact and systemic insecticide and miticide and, unlike most, does affect eggs and juveniles in addition to adults.


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## h_mossy (Sep 14, 2019)

I don't know anything about Azamax, but I love the name of the stuff. I think I'm going to try to find it locally.


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## Sky7Bear (Sep 14, 2019)

I have been battling white scale for a number of years now, but not mostly on Phrag. It has been difficult to deal with. My latest attempt is an insect growth regulator called Enstar. It has a good reputation, but it also is quite expensive (may see if any other members of my local orchid society need any, as it also comes in quantities that should last a lifetime). I was a little amused to see that insect growth regulators are also used in anti-flea medications and home treatments (don't ask).


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## Ray (Sep 15, 2019)

h_mossy said:


> I don't know anything about Azamax, but I love the name of the stuff. I think I'm going to try to find it locally.


Hydroponics shops often carry it, but Amazon might be the easiest source...



Sky7Bear said:


> I have been battling white scale for a number of years now, but not mostly on Phrag. It has been difficult to deal with. My latest attempt is an insect growth regulator called Enstar. It has a good reputation, but it also is quite expensive (may see if any other members of my local orchid society need any, as it also comes in quantities that should last a lifetime). I was a little amused to see that insect growth regulators are also used in anti-flea medications and home treatments (don't ask).


Boisduval scale can be VERY difficult to eradicate.

I had an outbreak once, and the only way I was able to get rid of it once and for all was to make a blend of acephate, imidicloprid and kinoprene (Enstar), and soak the entire greenhouse - plants, media, structure - three times at one-week intervals.


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## Sky7Bear (Sep 15, 2019)

Well, Ray, that was very ambitious of you! I just finished by 3rd weekly general spray, although I did not drench the pots or the greenhouse, and only used Enstar with acephate. Actually, I have seen no bugs since the first spraying (and that includes mealies). I'll now wait a month, and inspect every plant individually. IF anything comes back, I'll probably drench the plant at that point. There are, of course, a couple of the systemics that come in the form of surface mini-pellets, including imidicloprid, which they would also get. I remain concerned about the root-dwelling mealies. 

Since I've just been fighting dog fleas, it's interesting that both the topicals put on the dog as well as the professional house treatments include insect growth regulators--some the same ones we use on plants.


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## Ray (Sep 16, 2019)

With an IGR or not, I'd not stop now and wait a month.

Neither product is 100% effective, so there will always be survivors that either were missed by the treatment or managed to be less- or unaffected, so waiting gives them the opportunity to reproduce. That is exactly how resistant strains are developed.


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## southernbelle (Sep 16, 2019)

Ray said:


> With an IGR or not, I'd not stop now and wait a month.
> 
> Neither product is 100% effective, so there will always be survivors that either were missed by the treatment or managed to be less- or unaffected, so waiting gives them the opportunity to reproduce. That is exactly how resistant strains are developed.


Tristar was recommended to me and I’ve done 2 sprays, 7 days apart spraying foliage and pots/mix thoroughly. Was planning one more spray at same interval. Are you saying more than 3 sprays is needed? Also, since I’m only spraying 5 plants, can I keep the mixed spray from week to week or do I need to remix each time? I’m keeping the leftover cool and dark.


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## Ray (Sep 16, 2019)

southernbelle said:


> Tristar was recommended to me and I’ve done 2 sprays, 7 days apart spraying foliage and pots/mix thoroughly. Was planning one more spray at same interval. Are you saying more than 3 sprays is needed? Also, since I’m only spraying 5 plants, can I keep the mixed spray from week to week or do I need to remix each time? I’m keeping the leftover cool and dark.


No, the general recommendation is to do three treatments at the recommended intervals, then if the infestation resurfaces, do three more using a pesticide with a different mode-of-action (MOA).

Generally speaking, the recommendation is to NOT store diluted pesticides, but I believe that is primarily a safety measure. Folks rarely label their application devices, so it's possible to end up with a container of an unknown substance. A week or two is probably fine, but I'd put a piece of duct tape on the sprayer and use a marker to ID it, the dilution, and the date, and you should be good to go.


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## NYEric (Sep 17, 2019)

BTW, scale on Phrags is not common. ??? Wipe them all off and then treat with chemicals, soaps and oils.


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## Sky7Bear (Sep 18, 2019)

Southernbelle, was Tristar effective? Ray, I only stopped a month after 3 weekly sprayings of a combination of acephate and Enstar. I'm in that period now. Next month I will inspect each plant. I'd rather not do more general spraying, if it's not needed. If I find infestation at that point, Ray, what would you recommend next. Enstar and something else? I'm also inclined at that point to isolate any plants with infestation and only treat those, or throw some or all away. I'm aware of the possibility that they will achieve resistance, if they haven't already.


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## Ray (Sep 18, 2019)

Tristar is a neonicotinoid, MOA Group 4A, so you want to avoid anything in that group (Merit/imidicloprid, for example). Personally, I'd go with acephate, group 1B, organophosphates.

OHP published a good chart of MOA's


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## southernbelle (Sep 19, 2019)

Sky7Bear said:


> Southernbelle, was Tristar effective? Ray, I only stopped a month after 3 weekly sprayings of a combination of acephate and Enstar. I'm in that period now. Next month I will inspect each plant. I'd rather not do more general spraying, if it's not needed. If I find infestation at that point, Ray, what would you recommend next. Enstar and something else? I'm also inclined at that point to isolate any plants with infestation and only treat those, or throw some or all away. I'm aware of the possibility that they will achieve resistance, if they haven't already.


It was recommended by Jerry Fischer of Orchids Limited for scale. I’ve sprayed twice 7 days apart, thoroughly spraying foliage and medium after removing any visible scale with alcohol. One more spray to go, but so far, so good.


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## littlefrog (Sep 22, 2019)

Distance (Pyriproxyfen) has a similar (same?) mechanism of action as Enstar, and is translaminar. Which means it gets into the plant - a systemic, basically. This is what I use. Usually in combination with a couple other pesticides with different mechanisms of action.


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## justagirlart (Sep 24, 2019)

Acephate on one leaf killed the leaf


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## Ray (Sep 24, 2019)

justagirlart said:


> Acephate on one leaf killed the leaf


I have used acephate on my plants for decades and never seen any damage. What was the starting material, and how was it diluted and applied?


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## Sky7Bear (Sep 28, 2019)

I'm now back from a short trip to Southern California (with an expensive stop at Norman's Orchids!). I stored up some questions and comments while I was away and reading by tablet or phone. Ray, why do you recommend not using Tristar? Because it's a neonic and probably killing bees? I believe one of the other poisons you use is also a neonic. I don't mind using it in a greenhouse because I have no bees there. I would not and do not use it outside.

In looking in Amazon I see other brands of pyriproxyphen which are much less expensive than Tristar. Safe to use one of those after adjusting for differences in formulations. Has anyone tried any of these?


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## justagirlart (Oct 5, 2019)

Since acephate is systemic and had never used it on phrags I was cautious putting it on one leaf to see what happened. That particular leaf died. The rest of the orchid is still alive. The scale was not rampant, only a few spots, I just removed all the spots by hand daily, It never became a big problem. I am new and exploring different things. All I know is my results.


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## Ray (Oct 5, 2019)

justagirlart said:


> Since acephate is systemic and had never used it on phrags I was cautious putting it on one leaf to see what happened. That particular leaf died. The rest of the orchid is still alive. The scale was not rampant, only a few spots, I just removed all the spots by hand daily, It never became a big problem. I am new and exploring different things. All I know is my results.


You still didn't answer my questions about the starting material, dilution or application...


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## Ray (Oct 5, 2019)

Sky7Bear said:


> Ray, why do you recommend not using Tristar? Because it's a neonic and probably killing bees? I believe one of the other poisons you use is also a neonic. I don't mind using it in a greenhouse because I have no bees there. I would not and do not use it outside.


I did not and do not recommend that Tristar not be used. What I said was that if someone had been using another neonicotinoid-based pesticide, they should use one with a different MOA for the next round of treatments. For example, if you've been using Merit (imidicloprid), Tristar - also a neonic - is not a good choice.


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## likespaphs (Oct 5, 2019)

Ray said:


> ...if you've been using Merit (imidicloprid), Tristar - also a neonic - is not a good choice.



i completely agree (for what it's worth)
the only way that, in my mind, it would be okay to use tristar if you have used imidacloprid is that you never use imidacloprid again.
although tristar and imidacloprid are both neonics, the active ingredient in tristar is much stronger than imidacloprid. 
NEVER go from tristar to imidacloprid


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## Ray (Oct 5, 2019)

likespaphs said:


> i completely agree (for what it's worth)
> the only way that, in my mind, it would be okay to use tristar if you have used imidacloprid is that you never use imidacloprid again.
> although tristar and imidacloprid are both neonics, the active ingredient in tristar is much stronger than imidacloprid.
> NEVER go from tristar to imidacloprid


Sorry, but that simply doesn't make sense to me.

The idea of changing pesticides' MOA is to reduce the chances of breeding resistant bugs.

If you use imidicloprid and have failed to kill every last critter (typical of ANY pesticide application), the remaining ones may have a genetic tolerance to the action the pesticide uses to kill. Using an insecticide with the same MOA, like Tristar, will do nothing to remedy that except maybe "hone" the resistant strains to be even more resistant. So, you switch to an insecticide with a different MOA to increase the odds that those resistant critters will not be resistant to this mode, and will die. Using imidicloprid or tristar in the future is totally independent of that.


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## Frederick (Oct 6, 2019)

Hello, I find the most effective treatment is Cryptolaemus montrouzieri, a species of ladybird originally from Australia. They are unbelievably voracious and will rid you of scale within a few days. I have used them in my garden (and on my Paphs out for the summer) several years ago to extraordinary effect. You should be able to buy the larvae in your country (they are available in the E.U.).
Cheers.
F.


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## likespaphs (Oct 7, 2019)

Ray said:


> Sorry, but that simply doesn't make sense to me.
> 
> The idea of changing pesticides' MOA is to reduce the chances of breeding resistant bugs.
> 
> If you use imidicloprid and have failed to kill every last critter (typical of ANY pesticide application), the remaining ones may have a genetic tolerance to the action the pesticide uses to kill. Using an insecticide with the same MOA, like Tristar, will do nothing to remedy that except maybe "hone" the resistant strains to be even more resistant. So, you switch to an insecticide with a different MOA to increase the odds that those resistant critters will not be resistant to this mode, and will die. Using imidicloprid or tristar in the future is totally independent of that.



imidacloprid is not terribly soluble, somewhere around 600 ppm in water
Tristar (acetamiprid) is significantly more soluble ~2950 ppm
Safari (dinotefuran) is super soluble ~39830 ppm

as such, if you are changing your pesticide rotation and the imidacloprid is no longer effective (ie the pests have developed resistance to it), if you switch to tristar or safari to reintroduce neonics as a moa, switching back to imidacloprid (or even tristar if you've switched to safari) would definitely lead to developing resistance.
i believe that q-biotype whitefly are resistant to every neonic except safari


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## Ray (Oct 7, 2019)

I'm no expert on pesticides, but greater water solubility does not necessarily equate to more efficacy.


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## likespaphs (Oct 7, 2019)

Ray said:


> I'm no expert on pesticides, but greater water solubility does not necessarily equate to more efficacy.


with these, it does as per Dr Raymond Cloyd and other people who are pesticide experts as i am not


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## Ray (Oct 7, 2019)

Yes, I've communicated with him.

I'll take it as true that they might be stronger.


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## likespaphs (Oct 8, 2019)

Ray said:


> Yes, I've communicated with him.
> 
> I'll take it as true that they might be stronger.



they are


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