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by: Marilyn Pokorney
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 lungworm.
Slugs are inactive in cold weather and hibernate in
the soil.
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 rotting.
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 trail.
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 soil.
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: http://www.apluswriting.net/garden/slugs.htm |
