Re: [aroid-l] Amorph Blues

Neil,

I must respectfully suggest that adding vinegar to your spray mix
resulted in a net positive only due to the buffering of your water's
pH, which resulted in greater efficacy of the diluted insecticidal
solution-- and not due to some acidic dissolution of body parts.
May I venture a guess that your tap has a somewhat high pH/
alkalinity/ hardness ?

Certain insecticidal compounds exhibit an "ideal" pH range and
become less toxic to target pests outside of this zone.  Indeed,
many products specify a pH value which the tank mix must be
buffered to prior to application for best results (almost always
towards the acidic side of neutral).

I further suspect -but freely admit I am not an entomologist- that
spraying mealy bugs w/ lightly acidified water; i.e. spraying with only
a vinegar solution & no other insecticide- would merely result in soggy
mealy's with their exoskeletons fully intact.  You're likely to destroy
your plants before you reach a potential capable of "dissolving the
mealy's shells", either in part or whole.

Potential confusion over the effects of acidity may derive from the
common use of boric acid in the battle against cockroaches & other
crawling insects.  In this case however, the insecticidal properties of
boric acid have nothing to do with it being an "acid" but rather, the
absorbent quality each salt crystal or particle has (same principle applies
to diatomaceous earth, silica gel, etc.).  Hence a passing insect which
contacts the material has a patch of cuticle wax absorbed, resulting in
the insect slowly dehydrating via the breach.

In any event, if adding vinegar to your spray results in mealy slaying
synergistic pest control with no visible phytotoxicity, just keep doing it
whatever the reason!

 -Dan





Neil Gordon wrote:

>
> On another note, I had an infestation of mealy bugs last year, and i
> couldnt get rid of them until someone here suggested putting a little
> vinegar in the insecticde as it dissolved their shells.
>
> Does this acidic mix adversely harm or stunt the plants?
>
> The mix worked well on the Aloes they were munching - the bugs were
> unstoppable til i used that stuff!
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