mosquito spraying and ponds

Hmmmm, I guess I'll have to respectfully disagree after using Malathion LD
50 (per Dr.J's instructions in his book) for the removal of flukes in my
pond. Unless they're gonna rain droplets over the pond, I'd say the fish
are safe and the carbon would remove it after one pass.

Sorry to hear about the deer & car meeting, I doubt I could have even typed
anything close to legible after such an event. ~ jan

On Thu, 17 Jul 2003 23:36:11 GMT, "Gregory Young" wrote:

First off, the bacteria is actually Bacillus thuringiensis.. sorry about
that. I was in a bit of a hurry, and upset.. a deer and my car had an
encounter yesterday, (last one was back about 1984, so I guess I have been
lucky) so my typing was sloppy.
Malathion is, as I believe Ingrid said, very toxic. It is a cholinergic
poison, not very dissimilar from what you would know as a "nerve agent".
It is toxic to all animal life, only the LD 50 (lethal dose) varies from one
species to another.
I would not rely on charcoal, as Malathion will be absorbed by your fish
most likely well in advance of making a pass into a filter system!
Best advice is to cover your pond with a plastic, nonpermeable tarp (the
common blue plastic one works fine) on the day they spray.
You are looking for a tarp that can cover the surface, to catch falling
droplets/aerosols, so just have a couple of feet overlapping you pond on all
sides and you will do fine.
I would float some tires, etc to keep the tarp off the water surface, esp.
if it's on during the day, to allow air exchange.
Be careful when you remove it, so that any droplets won't roll off into the
pond.
You could of course ask them to "skip" you, but I wouldn't chance that the
message you leave gets through to the individual doing the spraying, so play
it safe and cover your pond..
I don't understand why quite a few of the local health departments are still
using Malathion. The larvicides work great, and are safe. Malathion is of
course cheaper, so that may be a factor... Fortunately our county
commissioners have agreed with our recommendations to stick with larvicides,
(even though we have a significant amount of WNV isolated from dead crows in
our region).
Happy ponding,
Greg


See my ponds and filter design:
http://users.owt.com/jjspond/

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
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