Slug mite
Encyclopedia
Riccardoella limacum or the slug mite is a member of the Acari (mite) family which is parasitic on slug
s and snail
s. Slug mites are very small (less than 0.5 mm in length), white, and can be seen to move very rapidly over the surface of their host, particularly under the shell
rim and near the pulmonary aperture
. While once thought to be benign mucophages, more recent studies have shown that they actually subsist on the host's blood
, and may bore into the host's body to feed.
Once infected, individual gastropods take longer to mature and show reduced mating, activity, and feeding. Infected slugs and snails lay fewer eggs than uninfected individuals. Infected gastropods also show decreased winter survival rates.
At least 31 species of mollusks are exploited. Common hosts include the following:
. Three species were subsequently named, though they were synonymized as Riccardoella limacum in 1946.
Mites have two sexes. Their five-stage life cycle is as follows: Females lay eggs in the host lung, and then the eggs hatch in 8–12 days as six-legged larva in the lungs of hosts and undergo three nymph stages. The whole life cycle can take place in 20 days under ideal conditions. Eggs do not hatch while the host is hibernating.
. Countermeasures include regular washing and introduction of Hypoaspis miles
, a predatory species of mite which feeds upon slug mites.
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s and snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s. Slug mites are very small (less than 0.5 mm in length), white, and can be seen to move very rapidly over the surface of their host, particularly under the shell
Exoskeleton
An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...
rim and near the pulmonary aperture
Pneumostome
The pneumostome is a feature of the external body anatomy of an air-breathing land slug or land snail. It is a part of the respiratory system of gastropods....
. While once thought to be benign mucophages, more recent studies have shown that they actually subsist on the host's blood
Hematophagy
Hematophagy is the practice of certain animals of feeding on blood...
, and may bore into the host's body to feed.
Hosts
Mite infection among gastropod populations varies greatly. Dense gastropod population favors infection; isolated populations may remain uninfected. Older and larger gastropods are more likely to show infection. Mites have been observed to move from host to host when hosts mate, and when gastropods congregate in moist soil and under rocks during the day. It has been shown that mites move preferentially towards fresh mucus when they travel along mucus, enabling them to follow mucus trails to new hosts.Once infected, individual gastropods take longer to mature and show reduced mating, activity, and feeding. Infected slugs and snails lay fewer eggs than uninfected individuals. Infected gastropods also show decreased winter survival rates.
At least 31 species of mollusks are exploited. Common hosts include the following:
- Agriolimax agrestis
- "Arianta arbustrum"
- Arion ater
- Arion hortensisArion hortensisArion hortensis, common name the "garden slug", "small striped slug" or "black field slug" is a species of small air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae, the roundback slugs....
- Helix aspersaHelix aspersaHelix aspersa, known by the common name garden snail, is a species of land snail, a pulmonate gastropod that is one of the best-known of all terrestrial molluscs. The species has been placed in the genus Helix, in all sources between 1774 and 1988 and in most sources until recently...
- Helix pomatiaHelix pomatiaHelix pomatia, common names the Burgundy snail, Roman snail, edible snail or escargot, is a species of large, edible, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae...
- Limax maximus
- Milax budapestensis
- Milax gagatesMilax gagatesMilax gagates, common name the "greenhouse slug" is a species of air-breathing, keeled, land slug, a shell-less terrestrial gastropod mollusk in the family Milacidae.-Description:...
- Milax sowerbyi
Taxonomy
The slug mite was first identified in 1710 by entomologist René Antoine Ferchault de RéaumurRené Antoine Ferchault de Réaumur
René Antoine Ferchault de Réaumur was a French scientist who contributed to many different fields, especially the study of insects.-Life:Réaumur was born in a prominent La Rochelle family and educated in Paris...
. Three species were subsequently named, though they were synonymized as Riccardoella limacum in 1946.
Life cycle
Slug mites are a one-host mite. It is possible for a mite to be born, live, and die on a single host.Mites have two sexes. Their five-stage life cycle is as follows: Females lay eggs in the host lung, and then the eggs hatch in 8–12 days as six-legged larva in the lungs of hosts and undergo three nymph stages. The whole life cycle can take place in 20 days under ideal conditions. Eggs do not hatch while the host is hibernating.
Economic impact and treatment
Slug mites are a concern for commercial and hobbyist breeders of snails; as little as six mites can sicken an individual and make it susceptible to infection by threadworms and bacteria such as Pseudomonas aeruginosaPseudomonas aeruginosa
Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
. Countermeasures include regular washing and introduction of Hypoaspis miles
Hypoaspis miles
Hypoaspis miles is a small light brown mite that lives in the top ½ in layer of soil. As a natural predator of fungus gnat pupae and snail parasite Riccardoella aspersa it is used by gardeners for biological pest control....
, a predatory species of mite which feeds upon slug mites.