Snails-Mollusks-Acariosis-Helicicultura-parasitic pathology in snails. Riccardoella limacum - Microscopic exam


Riccardoella limacum (known as the mite slugs) is a parasite of the genus Riccardoella, order Trombidiformes, family Ereynetidae affecting slugs and snails causing acariosis. This parasite, white or yellowish color, is about 0.3 mm and is provided with two pairs of sensory bristles and four pairs of legs in the adult stage with fixing ends that serve as gripping parasitize animals. This parasite is usually found in summer when the temperature increases and the humidity decreases.

The life cycle of this parasite involves a host which multiplies generally slugs and snails of the species Agriolimax agrestis, Arianta arbustrum, Arion ater, Arion hortensis, Helix aspersa, Helix pomatia, Limax maximus, Milax budapestensis, gagates Milax and Milax sowerbyi.

Riccardoella limacum is a hematophagous mite colonizes the mantle cavity (mantle cavity) or the lung of the host, where it feeds blood capillaries perforating Snail by salivary secretions. This parasite moves freely through the mantle cavity and its outer surface, being fixed to the blood capillaries to feed only. As part of their life cycle, the females lay eggs Riccardoella limacum in the lung of the host or between muscle fibers of the mantle cavity. In 3 days the eggs hatch as larvae in the lungs hexápodas host which then pass through three stages of nymph. The life cycle can take place in the next 20 days if ideal conditions are maintained.

Limacum Riccardoella transmission occurs from one host to another through direct contact between snails. However, this parasite can be transmitted through the soil, the plants they feed, clothing workers, waterers, troughs and other utensils. Acariosis is transmitted slowly but progressively. In infected animals, the eggs do not hatch Riccardoella limacum while the host is in the process of hibernation. Likewise, neither it is transmitted in snails in the free state during hibernation because the spiral remains within the outer shell protected by epigrama (operculum). However, in farms controlled environment Riccardoella limacum females lay eggs throughout the year.

Once infected, gastropods take longer to mature, reduce their mating and feeding activity. Likewise, slugs and snails infected manifest weight loss, sagging, anemia, lay fewer eggs and lower sperm concentrations. Furthermore, they have lower survival rates. It is estimated that a colony of mites is harmful, should exceed 100 mites per animal. In these cases, there may be a decrease helicícola population to 80% due to the strong anemic processes which are responsible these parasites. It is estimated that 20% of the remaining snails die within a few months progressive manner.


Recommended tests for diagnosis:


The diagnosis is based on microscopic identification of the parasite

Tests in IVAMI:


  • Microscopic examination for observing parasites.

Recommended sample:


  • Caracol supposedly infected.

Preservation and shipment of sample:


  • Refrigerated (preferred) for less than 2 days (for microscopic examination and / or molecular diagnostics).
  • Frozen: more than 2 days (for molecular diagnostics).


Delivery term:


  • Microscopic examination: 24 hours.

Cost of the test: