Enemies and diseases of snails

Last update: 12/27/2006

I will divide this large chapter in 6 categories:

A - Predators:

1 - The Flying predators:


The magpie	The geai	The corbel	The heron	The grouse	The dunnock	The pheasant

The blackbird	The titmouse	The redstar	The owl	The falcon	The jackdaw

The thrush	The duck	The goose	The owl	The black-headed gull	The moorhen

The most effective means for fighting against these birds, is to install a net.

It’s the same type of net which we puts above the cherry trees or the strawberry plants for protect the fruits from the starlings.

2 - The terrestrial predators:


The rat	The mulot	The surmulot	The shrew	The hedgehog	The dormouse	The newt

The mouse	The field vole	The lerot	The lizard	The grass snake	The slow worm	The rabbit

The badger	The wild boar	The frog	The toad	The chicken	The fox

The salamander	The long pitchfork	The fitchet	The marten	The weasel	The turtle

All these predators (except snakes) can be captured with this kind of trap which I often use. The hedgehogs, clamping plates and frogs are slackened in another place. Think of adopting a cat: it’s really effective!!!
For rats, I use 2 types of poisons which I put in a tube PVC. That protects the pellets from rain water, and the hedgehogs cannot eat some. Personnaly, I don’t use rat poisonned traps, it’s because I don’t want expose cats and childs.
The "nibbled" apex of the shell is a sign characteristic of an attack of rats.

The largest predator:

Who spread pesticides which make me die ?
Who puts in his garden blue pellets which liquify me ? (the pellets, are of Métarex, not droppings of Schtroumpfs!!)
Who buys nematodes to destroy me ? (on sale in all the good stocked garden-centers)
Who destroys my environment (disappearance of the hedges, urbanization, construction of the motorways, etc.......) ?
Who collects me without being concerned with my period of reproduction ?
Who stuffs me with Burgundian butter ?
Etc .....

Who am I ?

3 - The invertebrates:

The odorous staphylin called "the devil" (Staphylinus olens):

Length: 1.5 to 30 mm. This keen mollusc destructor is used to fight snails in the gardens.
It has a frightening weapon in form of powerful mandibles.

Don’t rub you her, or your small finger will remember it!

The male drile

The yellowish drile (Drilus flavescens):

The female, always larviform, lives in the snail shells of which she eats the contents.

The female drile

Gilded carabe (carabus auratus) or "flower stand" or "vinegar manufacturer".

Carabe grained (carabus coriaceus) 25-37 mm, one of greatest Snail’s eater carabes.

The male lampyre

The lampyre, towards shining or firefly (lampyris noctiluca):

It bites its prey with these appendices and an anaesthetic substance as well as digestive enzymes injects to him. There is thus an extraoral digestion, the prey is liquified and lampyre drink this liquid.

The lampyre female (15 à 20 mm)

Silphides (silphidae)

Adult silphides and larvae (here: ablattaria) is fond of delicacies snails.

Decollata (Linnaeus 1758) oR "The Snail Destroyer ruminated"

A snail, predator of snails, that’s not very current!

Coming from North Africa, them Rumina Decollata live from 1 to 1 year 1/2 and lay approximately 200 eggs per year. Only one coupling is necessary to produce fertile eggs. The eggs usually hatch in six weeks. Once released, it’s the last time where you will have to spend money fighting snails. During a certain time, slugs and the snails will be controlled without use of the toxic chemicals.

On sale on Internet......

And others .....


The lithobie	The opilion	The earwig	The beetle

B - The Undesirables:

The undesirables are not predator as a such bus they are not snail consumers.

	The mole The mole does not eat snails but the small rodents borrow the galleries to penetrate in the parks. To fight against this plague, I personally tested several methods. Two are really effective: the mustard gas and the "detaupor". The detaupor (photo): the detonator kills the mole by effect of blast. It remains often on the spot in small pieces. The gas: to insert in the gallery of chlorine for swimming pool ("shock"). On this last to pour bleach then acid chloridric. A yellow gas heavier than the air will penetrate in the gallery. To stop the latter with a small plank.
	The slug The slug is regarded as undesirable because it consumes the flour of snails. For fighting against these undesirable without chemicals, it's necessary install a board or a paperboard on the ground. A few days afterwards, they are all stuck below. It's then enough plunge them in a chlorinated water. Trap with beer is very effective but isn't selective for our dear snails.
	The fly The fly don't consume snails but she comes to lay on the dead snail. Maggots develop and are quickly propagated in the park (danger to eggs and the youthful ones!). The presence of flies and midges attest of a lack of hygiene and are carrying bacteria contaminating food. The fighting means are numerous: withdraw often died snails, see quotidiennemt. install a UV lamp (electrocution), but only inside. install ribbons of glue. protect them from water! insecticides during the underfloor space.

C - The parasites:

The riccardoella

The riccardoella:

The riccardoella (limacum?) is an acarina of snail.
White and visible with the naked eye, it sucks the blood of its hosts making them sensitive to other parasites.
On the following photographs, we can see them on a slug and a snail (fulica).

Snail’s breeders are particularly afraid by him, treatment : pulverization of pyrèthre when the parks are in underfloor space.

There is also the biological fight: the hypoaspis miles. This last is an acarina predator (of which the riccardoella), larvae of flies, millipede, plant louses, etc.... Possiblity to treat with snails in the parks.
	Hypoaspis miles

The angiostoma aspersae (nematode)

Angiostoma aspersae meets in an adult state in the snail pulmonary cavity where he produces larvae. It is a big size nématode (more than 2 mm). The larvae place themselves between the body and the Snail shell and can disunite the coat from the shell.

Means of fight

Phasmarhabditis hermaphrodita

The phasmarhabditis hermaphrodita (nematode)

It’s a parasitic nematode which penetrates under the coat by the respiratory opening: it’s there that the bacteria living in symbiosis with the nematodes proliferate causing the gastropod death.

One can distinguish in tranparence the nematodes devouring this snail.

Means of fight

Fasciola hepatica

The fasciola hepatica (the liver fluke)

The liver fluke (Fasciola hepatica),fasciolose trematode responsible, is a liver parasite and bile ducts, prosperous in the liver’s sheep and is occasionally met in horses. Very frequent and very pathogenic in ruminants, the fluke nourish imself
by blood and hepatic cells, grows then lays its eggs. But eggs of flukes can’t hatch in the sheep liver. A whole tour awaits them.

Eggs leave their host by the excrements. They are found then in the external, cold and dry world. After one ripening period, they hatch to let leave a tiny larva. This larva will be consumed by snail. In the snail body, the ditch will multiply before being ejected in the mucosities which the gastropod spits in period of rain.

These mucosities, in white pearls bunches shape, frequently attract the ants. They don’t remain a long time in the social jabot of ants. They leave there while boring it thousands holes, transforming ants into strainer which they close again with an hardens adhesive and this makes possible ant can survive this incident.

Means of fight

Means of fight:

Actualy, There doesn’t exist specific product to fight against the nematodes and parasitic snails trematodes.Tthe preventive methods calling upon the rigour and the care of the stockbreeder are most effective; a periodic disinfection of the material with bleach lower parasitism rate.

Here is an exhaustive list of the active matters used in fattening parks treatments (Source: wallex.wallonie.be)

Cyanamide
Calcic cyanamide
Delthaméthrine
Pyrèthrines
Pyrèthre
Dazomet
Formaldéhyde
Quicklime
Métaldéhyde

With regard to the nursery and the hibernation builging, they can be disinfected using a solution containing active chlorine or formol at least once the year.
3 months an underfloor space will be carried out on the whole of the interior and external buildings.

Personally, I use 2 products for the parks disinfection (or of the « escargotières »): the bleach and the quicklime.

1 - The bleach:

I don’t preconise the use of chemicals such as the "Grésil" for example. I prefer to use bleach.
I use it to disinfect all the material (mangers, tiles, stuck boards, stakes out of wooden, fabric out of plastic, etc.....). This disinfecting is pulverized.
The amount:
I buy bleach by 250 ml, proportioned to 9,6% a.c. (active chlorine) that is to say 36° chl (chlorometric degree).
The amount that I use is 1,2 °chl.
And how I make to proportion with 1,2°chl ? (very good question!!!)

Pour the 250 ml in one liter of cold water. You thus have 1 liter of bleach to 9°chl (36/4 = 9)
Then, apply the good old rule of three: 9/1,2 = 7,5
Now pour your liter with 9°chl in a bucket, and supplement with cold water to have on the whole 7,5 liters.

Your mixture is made!! the bleach diluted is unstable and isn’t effective if is old.

2 - The quicklime:

The quicklime will be widespread on the ground after the park ploughing, with the amount of 2T/ha (either 200g/m2).
There will be a second ploughing in spring, before sowing (grass, clover, radish, etc.....)

D - The diseases:

The mycosis of the layings

The mycosis of the layings appears because there is an excess of moisture or a bad quality of compost.
The abnormal colored eggs (pink, clearly, yellow or gray) are dehydrated or rotted. They should be withdrawn before they contaminate all the batch.


Above: a laying desiccated (the eggs retract)	Above: a laying with development of mycoses.
To compare, on the left, a normal laying.

The 90 days disease

This disease is not very known to date.
The snails let themselves die and a light blue liquid invades the shell.

That "would come" from special snail food containing copper traces which with the passing years concentrate and generate "the 90 days mortality".
Called 90 days because mortality generally intervenes at this period.

A study on the total colony count of the helix aspersa in breeding confirms this copper concentration problem in snail rearings. If copper seems to be the principal cause in charge, a bacteriological infection is not drawn aside by the biologists.

Another study carried out on the contaminated sites raises the heavy metals accumulation problem in the the snail food.

A prevention consists in sowing mustard in the fatening parks after several years of exploitation because the latter fixes copper.

E - The accidents:

The "accidents" arrive from time to time and can come from several causes: predatory, falls, electrocution, etc....
Useless thus to panic.....

F - Conclusion:

Part conceived and carried out by Jose Matéo (thank you with him!!!)

Are exposed in these pages the various predators, parasitic and pathogenic agents that a snail is likely to meet in nature wild state, and especially, in what imports us, in breeding, as well as the suitable remedies. In order to make it possible for any snail rearing candidate to understand that, when there is concentration individuals’, there is concentration of problems. And is preferable to know first of all, which allows to anticipate for avoid them and in the worst case better curing it.

Don’t forget that hygiene is the best remedy for all the evils, and that to park its livestock this isn’t only to deprive they of freedom but also, and especially, for protect they from the predatory ones.

Your snails will thank you !!!

On left: summary of all that precedes.