Re: [aroid-l] Mealy bugs on Amorphophallus.
- Subject: Re: [aroid-l] Mealy bugs on Amorphophallus.
- From: Dan Levin email@example.com
- Date: Sun, 16 Nov 2003 15:41:48 -0800
> Did you indeed eradicate root mealy bugs too with that Merrit stuff?
Yes, I did. Merit is a slow but rather effective systemic insecticide. It is a
chloronicotinyl compound which disrupts the post synaptic nervous system
in a number of specific plant sucking pests, root mealybug included. That
said, it's not worth beans as a miticide/ acaricide. I've also observed little
to no efficacy against fungus gnats, but then it's not labeled for any of those
particular pests- so there you go.
Imidacloprid (Merit, Marathon) is most commonly used here in the states on
turf (for cutworms, grubs, etc.), trees (often injected to control chafers, borers, etc.)
and as an alternative to Chlordane in structural pest control (subterranean termites
in soil). Imidacloprid exhibits very low mammalian toxicity, relatively speaking.
> How do you apply it as systemic stuff? Do you drench the soil when the Amorph is
Precisely-- a simple soil drench followed by a light watering in within 24 hours.
Very little product is required for treatment; 1 tsp. of the 75 WP/ 10 gal. water,
equivalent to 15 grams / 100 gal. water.
In my case, I initially applied it as a foliar spray for a faster knock-down of
the adventitious adult/ crawler stages. Imidacloprid will translocate both
upwards & downwards within the plant but is optimally taken up by the roots.
Spraying was immediately proceeded by a good drenching of every pot, to the
point of just draining off. I then watered everything in a bit the next morning for
Though Merit is noted for its long persistence in the soil (can last many months),
personal experience suggests making a follow up drench approx. 4 weeks later
to achieve root mealybug eradication in greenhouse/ pot culture. If I recall
correctly, all of my tuberous aroids were in active growth at the time of infestation
so I have no data to offer re: treating dormant tubers; though I would think the
inherent systemic properties of this compound would still prevail and any lurking
root mealy's would be eliminated. Certainly can't imagine such an application
could do any harm, unless it induced rot due to excessive moisture in the pot.
Hope this answers your questions and you haven't fallen asleep before reaching
p/s- Egads Wilbert! I suddenly realize that I'm extremely remiss in sending
you this year's edition of US presidential portrait(s). PLEASE accept my most
sincerest apologies in this regard. Will write directly under separate cover...