Killing the pests or my plants? Mealys and Scale

[ronaldhanko]

Very helpful thread.

[Discus]

I was reading a back issue of the AOS magazine (the one with a Rhyncholaelia digbyana on the cover), and someone was talking about using azadirachtin (the active ingredient in Neem oil) as a pretty potent weapon against scale and thrips. It's supposedly fairly low toxicity.

[lbishop52]

Originally Posted by northernorchids

Ok, my plants (and me) have had a very stressful year. We both survived the house fire last June. Poor plants went w/o lights or care in a smoky house for almost a week before I could get them moved out. Then they lived outdoors all summer. Fall/winter they had to live in the basement of our rental in crowded conditions but at least they had light and heat. During all this Mealy bugs started showing up. I tried to deal w/them but was to busy w/the house mess to keep up, so neglect made things get worse. Now we are back in our house and I'm trying to play catch up and I see scale has joined the mealys. A few plants I've tossed, others I've trimmed back dead stuff and removed ALL flower stocks (the flowers seem to be really attracting the mealys). I've cleaned trays, clips and name tags and sprayed them w/an insecticidal soap. I can't repot right now so I resorted to dipping each plant pot and all into a bucket w/the same insecticidal soup in it, then rubbing each leaf to remove bugs. My goal was to treat plant, pot and soil, getting into cracks and crevices that spraying wouldn't reach.
I've read on these boards to use a Bayer product that has a systemic in it, so I bought a Bayer product for fruits and vegs that is a systemic and plan to water all my plants w/that next week after they've had a change to dry out some. I may resort to dipping the pots in that also.
Any other suggestions? I hope I haven't killed them all, but at this point I figured the bugs were going to anyway.
I have mostly Phals and Oncidiums, a few Paphs, Pfrags and some misc. The Phals seem to have suffered the most.

Hi, use Bayer's Tree and Schrub..... on the orchids at a rate of heaping tsp of the granules per 6 inch pot. It is systemic and will last a long time. Good luck.

---------- Post added at 10:02 PM ---------- Previous post was at 10:00 PM ----------

Originally Posted by Discus

I was reading a back issue of the AOS magazine (the one with a Rhyncholaelia digbyana on the cover), and someone was talking about using azadirachtin (the active ingredient in Neem oil) as a pretty potent weapon against scale and thrips. It's supposedly fairly low toxicity.

How do you use it? spray it like Neem Oil? Where do you get it?? Thanks. lbishop52

[northernorchids]

Update. I got rid of my cactus (yes it did have scale). I just finished week 3 of watering w/the Bayer systemic. I not only watered my orchids, but every plant that is currently in the house (several go out for the summer and come in for winter), whether they had anything visible or not. I figured that would prevent re-infestation from other sources.
SCALE- inspection w/a magnifying glass found none, where before I would find some every week (those I previously found I removed w/alcohol or a insecticidal soap on a cutip or cotton ball). So I'd say that the scale is under control. I'll continue to watch for it.
MEALYS - I still found just a few of them in the leaf axils of a Paph and I found some suspicious sticky residue on the leaf of another plant but couldn't find any mealys on it. I cleaned both w/alcohol and sprayed w/a pyrethruim spray. Next week I if I find any I will switch to the oil or insecticidal soap spray if I find any. The Paph I found it on has been struggling anyway from my former neglect, but it is finally starting to show some new leaf growth so maybe it has a chance.
As a matter of fact, all of my orchids are starting to look better. Partially from getting rid of the pests, but mostly because I've gotten back on track with lighting, monitoring temps and keeping them watered/fertilized on a regular schedule. All but a couple are putting out new growth and a couple have flower stalks.
I'm going to do week 4 of the Bayer drench, then use it every few weeks after that. I'll keep inspecting plants every week and cleaning off pests if seen. I still need to find Malathion, next week we will be in the big city and I will look in the garden and farm supply stores there. But I'm only going to use that if I see problems cropping up again.
Thank you to everyone for ideas and suggestions. I think my collection is getting back on track.

[lbishop52]

I bought it at Lowe's and Home Depot. It is in a granule form so you can put a heaping tsp. per 6 in. pot and adjust up or down for the sizes. It will work systemically for you without having to spray or dip! So says Woodland Orchids guest speaker Linda at our Monthly Orchid meeting. Good luck and sorry for the fire. Hope you recovered. lbishop52

[silken]

One word of caution with the Bayer spray. It has .22% Imidacloprid which is the active ingredient. Merit has more, I think maybe 2% or 5% depending on liquid or granular. I used Merit for about 6 weeks in a row to get rid of scale. It did a beautiful job of that and the plant grew and produced 9 spikes this summer (a Miltassia). However all of the blooms were discoloured and strange looking. Finally the last spike put out some normal blooms. I am attributing this to using the Merit more often than the instructions advised and hope next year the plant will bloom normally. I would definitely use it against scale or mealy bugs again, but maybe not so much. I just thought I would mention that when I saw you were going to continue to use it on a regular basis. It's a systemic so I don't think it needs to be applied regularly once it gets in the plant's system.

[lbishop52]

Hi Silken, I was told to use the granules of the Bayer Tree and Schrub and the blue bottle says once a year? Any ideas on that? 1 heaping tsp to a 6 inch pot. ?? Help?

[silken]

Mine says apply once a year too. I mixed mine with water even tho its granular. Our society bought a huge agric. amount and divided it in small jars to sell to members as we can't get a lot of these things in small amounts or at all. The person who got it couldn't find a lot of info about application and somewhere found the info of mixing in water. I think it's incorrect actually, but it did work. But because the scale was not gone for a few weeks, and I read a thread somewhere on here to treat 5 weeks in a row, I did! It may have been a weaker amount someone was suggesting to do repeat treatments-who knows. I would think what you are doing is likely the correct way to apply it.

[lbishop52]

One can only hope they do not wipe out the whole collection with this experimentation! The speaker was an orchid judge and grower in Charlotte, N.C. called Woodlands Orchids. I can only hope. Her topic was HOW TO KILL YOUR ORCHIDS! and it was Halloween time. LOL. It was a great talk and I think I have done all the things she said to do if you want to kill your orchids. Happy growing and spiking. lbishop52 way down in Naples, Florida.

[Discus]

Originally Posted by lbishop52

How do you use it? spray it like Neem Oil? Where do you get it?? Thanks.

They were mainly using it against thrips, but noted a good result on scale as well.

It's the March 2011 edition, pp138-139. The authors of the article state they tried "Azamax" (1.2% active ingredient) and used 9.8ml (2 tsps) in 3.8l (1 gallon) of water with 1tsp of Dove detergent. They spray once a week for 6 weeks.