A study by Mig Living
Darkness, moisture, sliminess, hunger, thirst: tasting, drinking, drowning. Death.
Brief explanation of the study:
Motivated by a desire to protect my vegetable garden from slugs without the use of toxic chemicals or spending an arm and a leg on tin slug fences of unknown effectiveness, I performed a study last Saturday night to see whether placing beer in containers in said vegetable garden would kill slugs and, if so, which shape/size of container was optimal. In order to test slug beverage preference, I employed several brands of beer and one non-beer beverage.
- Catfood cans (both the full-size cans and half-size cans with the same radius but only half as tall.
- Plastic flower-pot saucers about ten inches across and one inch deep.
All containers were buried so that the top edge was even with the top of the soil. A total of eight containers were used. Six catfood cans (containers #1-6) were placed in the lettuce patch. Two saucers (containers 7 & 8) were placed two or three meters away, between the red beets and the radishes.
The containers were filled to capacity with the beverages and left in the garden overnight.
Contents of the containers (1-6 are the catfood cans, 7&8 are the plastic saucers):
- Ottakringer Helles
- Red Bull
- Red Bull/Heineken mixture
- Mixture of the other 4 beers
No slug preference for beer brand was expected. Some slug drownage was expected on the basis of previous reports. Random distribution of a few slugs per container was thought likely. No slugs were expected in the containers containing Red Bull, although ants were expected to construct a three foot-tall anthill overnight.
149 dead slugs were counted the next morning. Distribution between the containers was as follows:
Container depth plays no role in slug-trapping. Container radius seems to be important. The two saucers, which had much greater circumfrence/surface area, caught more slugs than the cans.
The biggest surprise was slug beverage preference. As you can see from the graph, there is a clear preference among arion distinctus for Schwechater, and their least-favorite beer is Heineken, tied for last with Red Bull (although the theory has been put forward that more slugs may have drunk Red Bull, but then jumped back out of the can afterwards; a second experiment utilizing time-lapse photography is planned once funding becomes available).
Something that has not yet been conclusively interpreted in this connection is the fact that the two larger saucers each caught an equal number of slugs despite containing, on the one hand, a mixture of the most popular beers and on the other the two least-popular beverages. It is possible, although unlikely, since it was only 2 meters away, that a different slug population inhabits the beet patch. It is possible that container size is a more important factor than contents. It is possible that the Heineken in the Red Bull in the saucer made the slugs drowsier and unable to jump back out.
It is also questionable whether the 6 beverages used in this experiment were sufficient – a larger-scale study with more types of beer would be useful.
Further research is necessary before a final conclusion on the beverage preference of arion distinctus can be drawn.