In article , "Joe Morris"
wrote:

I just started using the beer for slugs approach using a tuna can sunk flush
with the soil level. Did not catch any the first night. Topped off the can
tonight to try again.

Regards,

Joe Morris

[Repost; I didn't test to see if all links provided are still active.]

The alcohol content of beer is harmful to a slug or snail & will kill it
even in a "shallow" tray of beer, but the alcohol evaporates out of beer
very rapidly (the shallower the pool of beer & the larger the surface, the
briefer the effect, perhaps only an hour's effectiveness). The majority of
slugs & snails climb into & out of it completely unharmed. Controled
studies show these beer traps to be nearly worthless, though beer itself
certainly IS an effective attractant if you can get them to fall into
something they really can't climb out of.

The idea that slugs merely drown in it is partially wrong; they could
drown in three inches of water or more if the wall of the container was
too high for them to reach over with their slimy bodies. Once good &
soaked in beer (or even just in water mixed with sugar & yeast) their
"foot" won't adhere to the wall, but it takes several hours for them to
drown in "stale" beer that has the alcohol evaporated out of it as nothing
else in it is toxic to the snail.

If the beer were changed daily it would be more effective even in a
shallow trap, or would kill whatever climbed through the first hour of the
night. If the trap were three or four inches deep, however, more slugs
would drown in that (however slowly) even if it were in nothing but water
(though plain water wouldn't attract many). The best recommendation for a
home-made trap is a Yoplay Yogurt cup, which has inward-sloping slick
plastic walls that a radically self-sliming slug-foot cannot afix itself
on. Beer bottles per se also work because the wetted sliming foot cannot
hold onto the glass wall well enough to crawl upside down & back out of
the small hole. Such traps have to be buried to within an inch of the rim,
close enough to the ground that slugs smell the fermentation, but not
flush or beneficial insects will fall in.

Near-beer also works as a good attractant, though without the alcohol
content it is all the more important that the trap be one they cannot
reach themselves out of. STALE near-beer let alone stale beer does not
attract them; the Univ. of Colorado study said it worked only one full day
& beer had to be changed every other day to keep working, but in Univ of
Ohio study they changed the bait only once a week (though they were not
killing the slugs, they were taking population measurements).

The study at the Universitiy of Colorado whimsically discovered that slugs
dislike some beers & just won't pay attention them, but rather liked
Michelob & Budweiser, & were totally enamored of Kingsbury Malt (which is
not alcoholic & did not kill many slugs, but the Colorado study used
professional traps deep enough to drown whatever climbed in). The
Universitiy of Ohio study wasn't so much to test control measures but to
take population & size/age & species statistics for a given area. A slug
hide-habitat was set over a sunken container of beer as the bait, &
changed weekly. The slugs were not killed. They accumulated in the habitat
above the beer where they were counted, size & ages recorded, & species
identified, then discarded. The traps did not kill many of the slugs that
hid comfortably in the habitats after being attracted by the beer. In
this study beer was found to be a mediocre attractant overall, because
population estimates based on number of egg masses located was far greater
than could be shown with beer-traps.

But another study done inside greenouses found the attractant-rate of beer
to be very high in comparison to metaldhyde-based baits (unfortunately
they didn't compare to Slugo or EscarGo which is safer stuff). The study
was for four days only, performed in a series of greenhouses by the
Entymology Society of America, & they caught 300 slugs with beer but only
28 with metaldehyde bait. The Entymology Society did use the relatively
ineffective shallow pans flush with the ground.

Other findings from the whimsical Colorado study:
Slugs don't like Rainier Beer, Strohs, Pabst Blue Ribbon, Coors, or
Millers. Anyone who likes these beers lacks even the good sense of a slug.
Anheiser-Busch beers were across the board better liked, inducing one
soul to suggest a new brand, Slugweiser; but nothing equalled
non-alcoholic Kingsbury Malt in slug appeal.
Slugs don't like flat beer at all, they want it fresh.
Slugs don't like wine. Gallo Wine was slightly more appealing than
plain water, but not by much.

Phosphate baits such as Slugo & EscarGo are the least invasive to a
garden's organic balance; Slugo I believe to be the most effective
bait on the market, but would have to see a study to say for sure,
since individual impressions are notoriously subjective & often
wrong. The more toxic metaldehyde baits (Slug-it, Bug-geta,
Deadline) though relatively harmless do carry warnings about
harming mammals (dogs, children). Stronger muluscides are very dangerous
nerve-toxins & should not be tried. Even fairly "natural" Slugo I would
put inside a box rather than on the garden's soil. Some people complain
these low-toxicity baits are not as effective as toxic muluscides, but it
works well if a few things are understood: It won't work in heavy rains
because the dehydrating effect of the bait is eradicated by rainy wetness.
It won't work on very cold nights because slugs & snails are relatively
inactive. It won't work in an area wider than two to three feet, as if
there is plenty to eat inside a square yard, a slug or snail will only
travel as far as from its daytime hidy-hole to the plant, which could be
scant inches (& baby snails won't leave the plant at all but will hide
within the foliage & seal itself shell against dehydration until
nightfall). So a box laid on its side with bait therein, at under two-foot
intervals, will work best on a dry night after a day of rainfall, when the
temperature is cool but not awfully cold.

Snail-eating snails eat slug & snail eggs, & baby snails & slugs. They do
nothing about adult slugs & snails. So it takes a while to work but over
time there are fewer & fewer young snails or slugs growing up in the
garden. Here's a page about snail-eating snails:
http://creatures.ifas.ufl.edu/misc/g...ing_snails.htm
Here's details how to use them in the garden:
http://users.abac.com/goodsnails/How...te_snails.html
I used them once but may have turned them loose in too cold of weather too
early in spring. I think they worked a bit but the impression was too
vague to know for sure. As a rule there are no baby snails & slugs in the
garden extremely early in the spring, so none to be eaten, & the trick is
to turn snail-eaters loose when eggs are being laid. These snails are banned in
areas where they won't die out in winter, but legal in temperate areas to
release. The adults persist in the garden for two years but do not
successfully complete their life cycle in zones where there are chilly
winters so slowly die out of the garden. I will probably try them again
but at best they're no quick fix.

Snails dislike crossing copper & in raised beds a copper strip all around
the sides of the bed keeps slugs from climbing up into the bed -- but only
if the strip is a minimum of 2 inches wide (as tested at Washington State
University). Sad to say the copper strips sold in garden stores tend to be
one-inch or half-inch & won't stop slugs unless two or three strips are
used to reach the 2" minimum.

Traps can also be made out of dampened loosely rolled newspaper, in which
slugs will take refuge at dawn, & can be discarded by any number of means.
Then even the most moderate poisons won't be required. This also catches
earwigs.

A pet drake will also do away with ALL the slugs in the garden, & will
love you besides. They're very social & lacking a ducky harem will settle
for following you around to be petted & loved & fed going
"kakakakak-burble-gabble-kackakak" at you with deep devotion. But, they do
turn the slugs into slippery little goo spots all over the walkways.

In our area we have many snails & fewer slugs by comparison.
Except for the hostas which they are very hard on, mostly they eat stuff
that grows back so swiftly I barely see any harm done. I've thought of
giving up on hostas then I won't have to control snails for any reason at
all. For two years I made no effort to limit the snails' activity, & it
was only the addition of hostas that got me a little up in arms so that I
bought the predator-snails. By & large I find the slugs & snails
interesting, & capture a few to feed to my salamanders so I don't want any
of them being toxified. It may seem bewildering that anyone could LOVE
slugs, but many people do, & here's a couple of representative websites
for slug fandom:
http://web54.sd54.k12.il.us/schools/...an/default.htm
http://schools.4j.lane.edu/roosevelt.../likeslugs.htm

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/