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HELP! Need to kill mealybugs

Posted by counselor4444 6A NJ (My Page) on
Fri, Sep 25, 09 at 22:15

I think I have mealybugs on my orchids. I have about 16 phals in close proximity to one another and I have no idea how but yesterday I found what I believe to be mealybugs on one and today noticed some teeny tiny whitish/clearish dots on another phals roots. I think these are mealybugs. So, I am going to need to treat all of my phals as a precaution.

I understand that a solution of rubbing alcohol/insecticidal soap/water is best. What % of each should I mix together in a bottle? Will this harm my plants at all? Do I need to wash it off after I am done? How often should I continue to spray? Any other ideas or suggestions would be helpful.

Follow-Up Postings:

RE: HELP! Need to kill mealybugs

sorry, more questions:

1. do i need to change ALL the potting medium on all of the orchids (if so, yikes... that will take time and money to get all new fresh medium considering that I just repotted many) Half my orchids are in bark and half are in moss.

2. how do I apply the alcohol/soap/water mixture to the orchids? Do I soak the entire pot in a bucket of the mixture? Or just spray the plant? My concern is that there are eggs or bugs in the pot that may not be gotten if I just spray.

I'm very concerned about losing my collection.

RE: HELP! Need to kill mealybugs

Can you post a pic of what you believe to be mealy so we can confirm for you?

I killed off a mild infestion of mealy using simply Bayer Advanced Rose and Flower Insect Killer (available at lowes and home depot). Its systemic, containing imadicloprid. Worked wonders on my mealy AND scale! I went the route of insecticidal soap and it just didn't do anything for me. Granted, soap is known (at least in the interior landscaping industry) to be more effective on scale, horticultural oil being more effective on mealy.

RE: HELP! Need to kill mealybugs

The best solution is neem oil mixed with bath soap. Apply in the evening or early morning two times a week. Neem oil is an organic pesticide and there is no side effects. It is also safe for other beneficial insects like honeybees.
All the best.

RE: HELP! Need to kill mealybugs

sorry, one more... what about the use of just "garden safe insecticidal soap" in a bucket and soaking the entire pot?

RE: HELP! Need to kill mealybugs

I came home two nights ago and on one of my phals flowers I found two cottony masses together approx 1/4 of an inch in length. They weren't moving and almost looked like mini balls of thread sitting on the flower stem connected to the flower spike. I was so alarmed that I cut off the flower (and the corresponding bugs) before I could take any photos. So, no photos.

Then last night I was looking at another phal and found teeny tiny dots on its roots (like whitish, clearish). Almost like itty bitty flakes. I used a toothpick and scraped a few off. I know what spider mites look like and that's not it.

Now I see on a few plants leaves this:

Is all of this related?

I don't know if I can find neem oil. I read in this forum about the use of Bayer. Do I just follow the instructions on the bottle? Is there any certain percentage you should use for orchids? I assume the Bayer won't hurt the orchids in anyway? Do you recommend dunking the entire pot into a a bucket of the Bayer solution? Do I need to repot? Thanks!

RE: HELP! Need to kill mealybugs

ALWAYS follow label directions. BAyer Rose and flower works well. For mealies Bonide make a good killer as well, whitefly and mealybug killer.

RE: HELP! Need to kill mealybugs

I am so glad to find other's who have had one HELL of a time getting ride of MB's on orchids. I got a fantastically cheap Phal two years ago (end of year sale in the midwest), inspected it with a microscopic eye, brought it home, stored it in my "triage area", and it began to grow, put out another limb and bloomed spectacularly. Since I'd had it over a year, I put it out in my kitchen (where I have south facing sliding glass doors, and shelf units on the kitchen table) where the shelves are crowded mostly with SUCCULENTS and it bloomed amazingly well for 5 MONTHS.
Then.... I saw the mealy bugs. After over ONE YEAR (I've inspected the others, and will continue to inspect for MB presence) BUT I have done everything to get rid of the MB's on this amazing orchid, including using PURE alcohol, on swabs, on them. The MB's kept coming back. I rubbed with AGAIN with alcohol soaked swabs. Next day? They were back. I then sprayed PURE ALCOHOL on the little bastids: zip. I then did the ultimate: a 50% solution of witch hazel and alcohol/H20 and submerged the entire plant into it for 24 hours. Still there.
The plant is now sitting in the EXTREMELY cold garage. If the cold kills the MB, fine. If the cold kills the orchid, well, I tried.
The most puzzling thing (aside from them NOT DYING) is HOW they got there?? I keep these plants inside, and I PRAY that when I put the orchid among my succulents (when it had NO sign of MB and GORGEOUS flowers) it didn't infect them. My collection is extremely extensive.
If anyone has any more ideas on how to kill these f****rs, let me know at: (always use "Mealy Bug" in the subject box or I will dump the message unread). Thanks!

RE: HELP! Need to kill mealybugs

  • Posted by arthurm Sydney, NSW AUST (My Page) on
    Fri, Dec 6, 13 at 19:13

Did you try a Systemic insect killer such as Confidor? Active constituent: imidacloprid

RE: HELP! Need to kill mealybugs

Agree with Arthur. Use Bayer with that ingredient.


RE: HELP! Need to kill mealybugs

Most of the "Bayer Advanced" series (trees/roses/turf/3-in-1/more?) have imidacloprid (which bayer makes/invented) + other ingredients. imidacloprid is a systemic, it gets absorbed into the plant and kills anything that feeds on the plant subsequently. The other ingredients in each of the different products are usually contact killers, that take care of pests currently on the plant. You can find out the other ingredients for all of the products on Bayer's site and then research them. Just because they label a product for Turf doesn't mean it can't be used elsewhere.

These products are usually applied as sprays, and personally I would not spray them inside, but I do spray outside and bring plants back in after an hour or so. Can be tricky in winter depending on your zone.

I have had success with Bayer Advanced 3-in-1, for both spider mites and mealybugs. Had a very persistent mealy issue, tried neem for 2 weeks, and maybe it would eventually have worked, but I couldn't wait and neither could my plants. Bayer worked for me with a single application.

Imidacloprid also has the effect of killing bees and other pollinators, so maybe read up on it and make sure you are comfortable before going this route.


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