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This is a discussion on Is there a systemic pesticide for mealy bugs? within the Orchid Ailments / The Compost Pile forums, part of the Orchid Culture category; I've swabbed, dabbed, changed medium, etc, and still today saw a few mealy bugs--they just ...
I've swabbed, dabbed, changed medium, etc, and still today saw a few mealy bugs--they just won't leave will they?? Is there a systemic pesticide? Or if I keep doing the vigilant searching and treating will they eventually go away???
Orthene WP is a systemic a teaspoon per gal. of water,drench in the pot once a week for 3 weeks also spray the leaves with something like Safers to get ones that are present .
It should be used on the plants after moving them outside the smell will go in a day or so .
Here is info. on other sprays , don't think there are any names mentioned of sellers of it , I cleaned it up I hope !. You can PM. me for them . Hope this helps . Gin
Indoor Orchid Pest Control with
Bayer's "Merit" Insecticide
BAYER Advanced Garden Orchid growers are constantly on the lookout for infestations of various
orchid pests such as scale and mealybugs. There are ways of eliminating these insects such as
physically removing them (mostly scale) and topical/contact treatments with Neem Oil, alcohol, or other
common insecticides (e.g. pyrethrums). This is usually only partially effective since the pests in various
stages of development are well hidden and continue to multiply. Pesticides are also available that are
systemic where the chemical used becomes incorporated into the stems and leaves of the plant and
eventually kill the pests.
Orthene in its wettable powder WP form (dissolved in water) is commonly used, but it and similar
products such as Orthenex which is supposed to control certain diseases as well have very penetrating
foul odor and must be used outdoors. There is a granular material with systemic action called DiSyston
sold by Bonide that has been used by some .
The point of this article is to mention that the systemic insecticide imidacloprid, trade name Merit (also
known as Marathon), is a broad-spectrum systemic insecticide that has been used on orchids. It is an
odorless analog of nicotine, a chemical used in the past for controlling aphids. Imidacloprid is of low
toxicity (used in flea collars) and is classified by Consumers Union as a "reduced risk alternative
pesticide." It is expensive and the minimum amount for purchase is larger than most people need ($300
for 100 g . Several recent orchid bulletin board postings have pointed out that while
Merit alone is expensive, it is found as the sole active ingredient in the Bayer Advanced Garden - Tree
and Shrub Insect Control product (see above label). This is readily available at Garden Centers
including for about $19 for a 32 fl.oz. bottle and thus is a reasonably priced
source for this pesticide. Merit is very effective at very low use rates and according to the label remains
effective for 12 months. It is not sprayed on the plants but is used only as a soil drench where the
chemical is taken up by the roots and moved upward into stems and foliage.
This is NOT an endorsement for the product. The label does not say anything about its use on orchids.
Bayer apparently told someone that it was not worth the expense of getting it approved for orchids, but
that it probably could be used safely. I have used this product (recommended rate one tsp/gal) on some
orchids this spring but have not made any definite conclusions. I still prefer to clean any infested plant
with an alcohol rub prior to any systemic treatment and my trials should be more organized. The growth
of the treated plants did not seem to be affected. As with most systemic treatments, you can not expect
a severely infested or weak plant to be cleared of insects overnight, if at all. If you decide to try it,
please follow all instructions.
As an unsubstantiated followup, a note recently has been posted mentioning that there is a
Bayer product available that contains both a systemic and contact insect killer that possibly can be used
on orchids. The label on Bayer Rose and Flower Insect Killer indicates that it contains the systemic
acting imidacloprid (Merit) and contact acting insecticide cyfluthrin. I have not been able to find this
product to test. Please let me know if you find it somewhere or have used it.
Of course the best way to keep pests out of your orchid collection is to purchase bug-free plants in the
beginning. However, the little rascals are adept at hiding, multiplying and spreading quickly. A good
practice is to isolate and inspect all new plants for awhile and watch for any infestations.
Chuck VanDyke (email@example.com) Author of the article .
Last edited by Gin; August 17th, 2007 at 08:26 AM. Reason: oops
I thought I liked that stuff at first, but the mealies were back about 3 weeks later, and pretty soon it was hardly working at all. sigh
I keep a bottle of the concentrated Bayer Tree and Shrub...purchased at my local Big Box store. I use it as a drench into the medium and it works well. I believe in rotating insecticides and due to a recent scale infestation I cleaned 135 plants with a toothbrush and alcohol spray. Removing dried paper sheaths as I went. I then used Enstar II as a drench...it is also a systemic.
I use 2 tbls of vegetable oil in a gallon of water and spray them directly. Do it religiously every week and they'll be gone. Make sure you shake the container very well as the oil and water seems to seperate. This is especially good to use if you have kids or pets around because it's non toxic. BTW welcome!
Good advise! I've been plagued with mealies on my salvia, but not a one on my orchids. AHAA! Sacrificial salvia may be the key! Thanks for all the great info, all.
I experienced quite a bit of scale and mealybugs last winter and spring. I also had an ant farm in progress in the greenhouse. They were the tiny red ants as small as a grain of sand. Virtually invisible they were so small. I sprayed Orthene WP twice at two week intervals and knocked out the ants and other insects at the same time. I have seen no ants in the greenhouse since and the other insects are non existent. I am a strong believer that if you control ant populations you eliminate insect problems.
Great info I'm waiting for the last bloom to fall then I'm going in with shock and awe using one of the suggested pesticides. I bought a better bigger magnifying glass too !!