> Birds (swallows) may make some impact on the skeeters, but when they are
> swallow-food, the mosquitoes are already out and biting things and laying
> eggs. The best predators are those that eat the wriggler larvae of
> mosquitoes, and the so-called "killifish" or mosquito-fish of the genus
> *Gambusia* are known to be very effective as mosquito control agents.

Oops. Gambusia ain't killifish! They're livebearers, closely related
to the common guppy.

Killifish are egglayers from Africa (actually, perhaps elsewhere too,
but these are the ones I know about). They live in essentially
seasonal mudpuddles. Lay their eggs in the mud as the pond dries
out, where they lay dormant until the next year's wet season.

Some species only live a few weeks, and the eggs of some species
must be kept out of water in dryish conditions for months before
they hatch.

Actually, come to think of it, I'm almost certain there are killifish
or close relatives here in the new world. I'm sure, though, that
one of you birders will probably turn out to be an icthyologist and
set us straight.

Tweeters! Gotta love it!
> I'm
> told these fish can be readily obtained and released, and are hardy. And they
> are in turn fed upon by the fish-eating BIRDS (kingfishers, herons, grebes,
> etc.)!

Gambusia have fallen out of favor in at least parts of the country,
due to the fact that they compete with native species.

Don't know about here in the PNW, though.

The species of mosquito most common in western Oregon marshes can
be controlled by controlling water levels. This is being done
in Portland's Oak Bottoms wetland area. The mosquito lays its
eggs in moist mud at lower water levels, which then hatch when
water gets high (hey, sounds a lot like killifish!), so the
area is controlled to keep water levels constant during the season.

This changes the character of the wetland considerably, but as it's
in a populated area chemical control had been proposed. Controlling
water levels was adopted as the less harmful management technique.

-Don Baccus-