On 16/08/2014 07:48, Martin wrote:
On Fri, 15 Aug 2014 22:54:08 +0100, Sacha wrote:

On 2014-08-15 19:31:45 +0000, David Hill said:

On 15/08/2014 19:27, Nick Maclaren wrote:
In article ,
Sacha wrote:
snip

I was thinking mainly of the garden of a hotel in Corfu which had
(apparently) been sprayed with paraffin. It absolutely reeked and it
does seem a very dangerous method! This was back in the mid-70s.

Ah, no, that's not what they had done. Mosquito larvae hang from
the surface of stagnant water, which is why draining the Fens
eliminated marsh ague a century or two back. The usual method
of preventing that is to put a small amount of oil in, and that
kills the larvae. Paraffin is cheap and not very volatile, so
is safe, but it does stink when it evaporates (e.g. on a hot day).

You can also use detergent, but that usually needs a LOT more and
taints the water worse.


Regards,
Nick Maclaren.

I've found that if you give a quick spray with an aerosol fly spray
over the surface it kills off the mosquito larvae and doesn't leave any
deposit on the water surface.

Good tip!

Olive oil works too.

And doesn't kill the fish.

This is printed on every fly spray can I've ever seen:

"Very toxic to aquatic organisms. May cause long-term adverse effects
in the aquatic environment. "
--
Phil Cook