Monday, June 1, 2009

Attractiveness of Beer & Fermentation products to the Gray Garden Slug

Below is the link to the full report done by CSU.

I will give just a couple of highlights here.

All trials were conducted in a heavily vegetated yard in Fort Collins, Colorado during April and
May 1987. Attractants were evaluated based on slug captures in a commercially available slug
trap (Slug Saloo#, American Quality Products, Denver, CO) that measured 9.5 cm in diameter
and was covered to exclude dilution by rainfall and irrigation. Approximately 180 ml of liquid
were placed in each trap during trials, which filled the containers to within 2 cm of the container
lip. Traps were placed among vegetation, arranged in a randomized complete block design with
4 replications. Individual traps were separated by a minimum 0.75 m. Traps were collected 48
hours after placement, unless otherwise indicated. All data were subjected to analysis of
variance (ANOVA). Means among the treatments were separated using the multiple range test
of Duncan (1955) at P < 0.05.
Attractiveness Comparison Trials of Commercial Malt Beverages. Trials were conducted to
rank commonly sold malt beverages for attractiveness to slugs. Treatments included 12 brands
of beer, one alcohol-free malt beverage, sugar water/baking yeast, one brand of wine, and tap
water. Comparisons were made during a series of trials involving three treatments against a
standard beer (Budweisera) that was used in all trials. The ratio of slug capture in treatments
was then calculated against the (Budweiserk) standard to establish overall rankings of
Beer Flattening/Alcohol Fortification Trials. The effect of beer flattening and alcohol
fortification on slug capture was evaluated with two beers (Budweise?, Pabst Blue Ribbo$). In
both trials, beer was flattened by decanting into a bowl 48 hours before the initiation of the trial.
To further help define the importance of the ethanol in beer to slug capture, additional treatments
were conducted involving fortification of the baits with ethanol. Ethanol was added at the rate
of 6% by volume in the form of 95% ethanol.

And the results

A wide range in attractiveness occurred among the various malt beverages tested (Table 1). The
non-attractiveness of alcohol, demonstrated by Smith and Boswell (1970), was emphasized in
this trial since greatest attraction occurred using the non-alcoholic malt beverage Kingbury Malt
BeverageR. Among tested beers, there was a three-fold range in attractiveness with the brewer
Anheiser-Busch products (Micheloba, Budweisep, and Bud LightR) attracting the greatest
number of slugs to the traps.
Several volatile components associated with beer have been identified by Selim (1976) as being
attractive to slugs including acetoin, diacetyl and dihydroxyacctone. The range in attractiveness
of various malt beverages are likely due to differences in the concentrations of these attractants.
For example, Meilgaard (1975) reports a three-fold range in diacetyl exist? among typical United
States beers.
The single wine tested (Gal10 Pink ChablisR) was not attractive to slugs, although Smith and
Boswell (1970) reported that unfermented grape juice was a moderately attractive to slugs. Use
of fermenting sucrose solutions to which baking yeast was added produced capture rates similar
to beer. Selim (1974) had previously reported sucrose fermentation byproducts as attractive to

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