On 2014-08-17 08:08:14 +0000, Martin said:

On Sat, 16 Aug 2014 14:25:46 +0100, Sacha wrote:

On 2014-08-16 07:05:13 +0000, Phil Cook said:

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. "

Two of our ponds have fish in but one is a wildlife pond which has no
fish and if we get mozzies that's where they'll come from. It has an
industrial quantity of duckweed, too, but that's another problem.

One of our neighbours has a small fish pond. Judging from the number of small
frogs and dragonflies we find in our garden fish, and other pond life are not
totally incompatible.

We get those, too but one pond in particular, has a really large number
of fish. We've noticed that the number of tadpoles that hatch and
survive each year has diminished over the 14 years I've been here. So
the wildlife pond is primarily (in our minds) for frogs. We get lots of
dragonflies and damselflies round all the ponds.
--

Sacha
www.hillhousenursery.com
South Devon
www.helpforheroes.org.uk