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.