I use a systemic with active ingredient imidacloprid, various brands(bayer, scotts, dominion etc) available in garden centers/hardware stores in california contain it. It does take several applications to work but has helped control scale on various orchid genera.

Nick,

for over one year, I have used:

Bayer Advanced, Complete Insect Killer . The active, long-term pesticide in this product is imidacloprid, 0.72%. There is also a short-term pesticide included in this product but I won't bother discussing it since that isn't a concern. Imidacloprid is an outstanding product for protecting orchids from run-of-the-mill bugs. You will be amazed at its effectiveness.

I purchase/use the product which is dispensed from the hose. It's one helluva lot faster that way!

--Stitz--

Bayer advanced was the first thing I used. I appeared to have little effect. A member in my society swears by it but he applies it several times. The orthene needs a full protective suit with breather but one application is good for 9 month.

Do you apply the Bayer once and you are good for a long period of time or do you use it more often? Scale are the real problem as aphids and mealies are much easier to controll.

Nick

I applied bayer advanced weekly with the normal watering and feeding for six weeks and it was a quite effective control. Orthene(which I successfully used on my roses for thrips) seemed to have little or no effect on scale. But scale is, imho, a very very difficult problem. You are controlling it with Bayer, but given its lifecycle, propagation habits and ability to survive through chemical treatment, once established, will be something that needs to be controlled on an ongoing basis, short of destroying infected plants. I watched an entomoligist lift one scale cover under a powerfull microsope to reveal thousands of "crawlers" invisible to the naked eye. Best I hope for with scale is control not eradication.

Nick,

Bayer Advanced, Complete Insect Killer needs to be treated on a regular basis until the plant is systemically protected. I don't know exactly how long it takes before that process is complete. I didn't "dose" my plants last winter after ~ November until I put them back outside the following March. I had complete protection from insects.

I am relying on this same treatment protocol for this winter, 2010-2011. Prophylactic treatment through time is a far superior strategy.

--Stitz--

Nick,

FWIW, about 4-5 years ago I had a bad issue with brown scale on 20-25 phals. Back then I had tried the Miathalon? and other various treatments with little sucess. I then purchased some Bayer Advanced Tree and Shrub Insect Protector (no longer available, now it's the Bayer Advanced Insect stated above -- I use it 3 times before bringing plants in for the winter--) and treated(watered) all 'kids with it once a week for 5-6 weeks. Never had another issue with brown scale. I know the current stuff will eradicate spider mites, but as stated I've not had brown scale issues lately so can't comment on it's effectiveness in eradicating an existing problem. The old stuff sure did the trick though.

Bob

Bayer Advancedis readily available at HD, also comes in a more concentrated form in a larger container at a local agricultural center. I only used it once on the plants which sounds like it was the mistake. It seems less intrusive than the Orthene so I think I will treat the affected area with it 3 or 4 times.

I did get the outbreak under control, just was flabergasted that they came back despite my efforts, maybe perfection is not the goal. As stated above, limiting them rather than eradicating is the goal. I can live with that however would like to eradicate them if possible.

Nick

Bayer Advanced, spray and granular systemic. You have to go Major Crazy to get these suckers! Spray the heck out of them, and apply the granular systemic every two weeks. I ignored the directions ('provides protection for 90 days), and used the granular every 2 weeks and sprayed every week for a month. What is left of the plant is making some new growth.

One other thing I did was spray the plants with an oil concoction I make. The dying leaves were shiny from all the oil, but the plants are recovering. Smother those suckers!

I had a really bad infestation but it seems 'under control' not cured. You need to really stay on top of them.

(sorry, I get very emotional when thinking about these monsters.)

Jane

I bounced around the internet for a few days and made numerous phone calls. A company called SYNGENTA makes SUPRACIDE which is used by the agriculture types and is super effective against armored scale. Not available in California but can be purchased in Arizona. As I talked to a very knowledgeable sales man in Phoenix, he advised me that, as Stitz pointed out and others confirmed, Imidachloprid is the most effective agent against armored scale. Oil and soap for spot treatment.

Bayer Advanced, Complete Insect Killer is the choice then as it is easy to get and easy to apply. My situation is less critical, I overreacted and shot from the hip a few days ago. I carefully examined every one of my Cattleyas during the last few days and found a small number of scale on a total of 4 plants out of several hundred. The situation therefore is under control and my past efforts were good enough, sort of. Complete eradication was not achieved but no need to hit the panic button, spot treatment is probably good enough, I plan to treat the whole group of plants with the Bayer to keep these kritters down as much as possible.

Nick

I use Merit 75. I use it as a drench (dosage is 1/8 teaspoon to a gallon of water). For several reasons. One, I don't want the spray to go everywhere. And two, I don't have to worry about missing any areas on the plant. Three - the plant absorbs the product as I am watering it into the medium and being taken up into every portion of living tissue. Insect bites - whether it is on the roots, leaf tips or some hiding place of developing leaves/pseudobulbs/flowers - and the product is taken in.

I have used many of the pre-mixed systemic sprays - which are nice - but found that some critters where either not touched or the percentage of ingredient necessary was in minimum dosage for the job necessary.

I apply once a week for three weeks for scale and an extra week for mealys - I suspect they are more a 'traveling' critter and till they 'land' and feast, needs the extra week.

First two weeks you don't notice any difference. By week three the scale blow away like snowflakes. Week four, mealies are like mushy white globs.

After the necessary application I am totally free of scale and mealies. I just have to watch for thrips, but that is a far easier critter to contend with.

Couldn't the Bayer Advanced also be used as a drench?

Another question: Do you guys/gals use breathing masks when spraying your plants? During good weather this could be done outside, but during winter one works in a confined area. I wonder if spraying year after year could become a health hazard? I am still using Melathion in the GH for most of the critters (Investation is not too bad though.)

I don't use sprays (except homemade) inside the house. I do use systemic granular inside. I've been waging a battle with scale and I really think the combination is working. Its really a matter of staying on top of it.

I just can't imagine how dangerous it could be to use those sprays inside. I wouldn't do it. Use a granular systemic.

Jane

Haven't had a scale problem in years but used Cygon 2E with great results as a last resort several times in the past.

I use Bayer Advanced Rose and Flower Spray. It's premixed and very handy for only a few plants. I use it once every seven days for three times, even though it's a systemic. I also drench the soil, as eggs lurk there, and if you keep only treating the top, they keep hatching below. Indoors I'm very careful to control the spray, don't use it as a broadcast mist, and I wear disposable gloves.

Focus on getting rid of ants. They are the farmers of scale and aphids.

Cygon is good stuff. It's like the thermonuclear bomb when it comes to scale insects. I haven't yet resorted to it, yet....

--Stitz--

I, too have been battling brown scale, I finally let go of the super-crunchy, all-hope-is-lost orchids I inherited at work. the bark was crawling with thousands of larvae. Some of the other inherited orchids are now cropping up with scale.

I purchased Rose Rx concentrate with:
Tebuconazole .80% and
Imidicloprid .15%

The instructions say to treat plants 4T to 32 oz h2O per plant every 4-5 weeks for sandy soil (considering bark is fast-draining like sand I was planning on following those directions, however, - I've seen some people in this thread say they treated their orchids every week with imidiloprid in addition to watering and fertilizer. should I ignore the instructions and go that route? if so, should I mix it all together or apply fert, Water & systemic treatment in a certain order? Many, many thanks for any insight / information.