Slugs are major pests of horticultural plants throughout the
world. They are destructive pests of home gardens,
landscapes, nurseries, greenhouses, and field crops.
Slugs also pose a health threat to humans, pets and wildlife
by serving as intermediate hosts for parasites such as
Slugs are inactive in cold weather and hibernate in the
Heavy mulching and watering, required for productive and
beautiful gardens create favorable conditions for slugs.
Slugs destroy plants by killing seeds or seedlings, by
destroying stems or growing points, or by reducing the leaf
area. Slug feeding may also initiate mold growth or
Slugs feed on a variety of living plants chewing holes in
leaves, flowers, fruit and young bark. They are also
serious pests of ripening fruits, such as strawberries and
tomatoes, that are close to the ground. However, they will
also feed on foliage and fruit of some trees favoring
citrus. Some plants that are seriously damaged include
artichokes, asparagus, basil, beans, cabbage, dahlia,
delphinium, hosta, lettuce, marigolds, and many more plants
too numerous to list here. To determine if damage is caused
by a slug or other insect, look for a clear, silvery mucous
Under ideal conditions, chemical baits, containing
metaldehyde, can be somewhat effective because this aldehyde
paralyzes the slugs and they eventually die from
dehydration. However, under cool and wet conditions when
slugs are most active and troublesome, they can often
recover. And these chemicals are poisonous to cats, dogs,
birds and curious children.
Biological control provides an attractive alternative to
traditional control practices. Nematodes possess
exceptional potential as biocontrol agents for pest slugs.
In Europe, a product as been successfully developed from
Phasmarhabditis hermaphrodita, that is effective against a
wide variety of pest slug and snail species and it targets
only slugs and snails.
It would be a perfect solution for introduction into the US
but there are no published records of P. hermaphrodita
occurrence in the US. Thus, regulatory issues prohibit it's
introduction and marketing in the US.
Slugs do play a positive role in the environment. Because
slugs are also scavengers eating decaying vegetation, animal
feces, and carrion they help in breaking down decomposing
materials thus helping to release nutrients back into the
Slugs are night feeders so night traps and beer traps are
the best ways to catch and trap them. But there are many
other methods proven successful. One includes a very
common, but not well known, ingredient.
For more information:
This article © copyright Marilyn Pokorney 2005
Author: Marilyn Pokorney
Freelance writer of science, nature, animals and the
Also loves crafts, gardening, and reading.