Slugs symptoms and treatment

Plant problem database / Information about Slugs

Slugs symptoms and treatment

A snail without a shell.
A mollusc with an elongated, soft body with a shiny appearance due to the slime coating.

Symptoms of Slugs

Similar to that of snails. Foliage is eaten, usually the outer margins where the slug travels.
Evidence of activity is often given by the reflective trails that remain after the mucus trail, which they travel on, dries.

Remedies for Slugs

Cultural controls: Mulch provides an ideal slug habitat so mulch lightly around plants that are attractive to slugs.
Water only in the morning so that the ground will dry by evening when slugs are naturally active.
Prune lower leaves or stake large plants to reduce potential hiding places for slugs and allow better air circulation which helps keep the soil surface drier
Trapping: Beer traps can be used early in the season, when the slugs’ favoured foods are more scarce, as slugs are attracted to the smell of beer. Such traps have various designs, but essentially the slug will venture into a half buried jar, or cut away plastic bottle, containing a small amount of beer (not stout or lager), succumb to the fumes and drown.
Physical removal: Night time patrols for hand collection can be useful. These can be augmented by regularly setting out traps such as boards, shingles, overturned flower pots, or grapefruit halves for slugs to hide under.
Barriers: Slugs have an aversion to copper. Copper pipe can be used and commercial slug rings are available. A 15cm length of plastic pipe with copper foil tape around it can be used to protect individual plants.
Repellents: Grapefruit and other citrus rinds, used coffee grounds, eggshells, and sharp sand can be used in gardens around plants to repel slugs.
They also find dry surfaces difficult to cross since they must extrude a wet slime coat in order to move and this can eventually lead to dehydration, so leave cleared borders or walkways around plants.
Pesticides: Commercial slug pellets containing metaldehyde or methiocarb are available, but are not approved for organic gardening as they can poison creatures at a later stage of the food chain.
Aluminium sulfate can also be used; its proponents claim that it is less toxic to the environment.
Salt will kill slugs, but is also poisonous to plants.
Organic pesticides: Diatomaceous earth is a natural abrasive that can cause small cuts or scratches on slugs, causing them to dehydrate.
Bait pellets containing iron phosphate are also used for this purpose.
The mixture of 50% water with 50% ammonia will kill slugs instantly. This can be applied using a hand spray bottle early in the morning or during a warm rain.
Alternate hosts: Comfrey can be used as a decoy by placing the leaves around plants to protect them. The slugs will eat the comfrey and leave the protected plant alone. This is a honeypot approach, and rarely effective as it merely increases slug populations in the longer term unless comfrey is used as a trap crop and the slugs are controlled on it.
Predators and parasites: Frogs, toads, snakes, ground beetles, ducks, pigs, birds.
Biocontrols (microscopic): A recent development in the control of slugs is the introduction of ‘Nemaslug’, a microscopic nematode (Phasmarhabditis hermaphrodita) that will seek out and parasitize slugs, reproduce inside them and kill them. The nematode is applied by watering onto moist soil, and gives protection for up to six weeks, though is mainly effective with small and young slugs under the soil surface. The nematode is only effective in warm, moist conditions, above about 20°C.
[source http://en.wikibooks.org/wiki/Horticulture/Slugs ]