Intensity of parasitic mite infection decreases with hibernation duration of the host snail

Abstract

Temperature can be a limiting factor on parasite development. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. The prevalence of infection by R. limacum in populations of the land snail Arianta arbustorum is highly variable (0-78%) in Switzerland. However, parasitic mites do not occur in host populations at altitudes of 1290 m or higher. It has been hypothesized that the host's hibernation period might be too long at high elevations for mites and their eggs to survive. To test this hypothesis, we experimentally infected snails and allowed them to hibernate at 4°C for periods of 4-7 months. Winter survival of host snails was negatively affected by R. limacum. The intensity of mite infection decreased with increasing hibernation duration. Another experiment with shorter recording intervals revealed that mites do not leave the host when it buries in the soil at the beginning of hibernation. The number of mites decreased after 24 days of hibernation, whereas the number of eggs attached to the lung tissue remained constant throughout hibernation. Thus, R. limacum survives the winter in the egg stage in the host. Low temperature at high altitudes may limit the occurrence of R. limacum.

Parasitic infections in mixed system-based heliciculture farms: dynamics and key epidemiological factors

“…Regarding the first possibility, only the mean abundances of R. limacum were significantly affected by the process, which is in accordance with recent studies indicating that larvae, nymphal stages and adults of this species are unable to survive prolonged exposure to 4°C (Schupbach and Baur, 2010;Haeussler et al 2012). Eggs of this mite, however, can resist hibernation in the host pallial cavity without hatching (Haeussler et al 2012). In agreement with these findings, no reduction was observed in the presence of R. limacum eggs detected in H. aspersa after artificial hibernation (data not shown).…”

“…These findings could be suggesting that certain parasites are especially sensible to the low temperatures used in the process, and/or mortality associated with starvation occurs more frequently in snails supporting mixed infections. Regarding the first possibility, only the mean abundances of R. limacum were significantly affected by the process, which is in accordance with recent studies indicating that larvae, nymphal stages and adults of this species are unable to survive prolonged exposure to 4 °C (Schupbach and Baur, 2010; Haeussler et al 2012). Eggs of this mite, however, can resist hibernation in the host pallial cavity without hatching (Haeussler et al 2012).…”

Parasitic mites influence intra- and interpopulational variation in sperm length in a simultaneous hermaphrodite land snail (Gastropoda: Helicidae)

“…The elevational decrease in sperm length could at least partly be explained by the lack of parasitic mites in alpine populations, because mites do not occur in snails living at elevations above 1500 m (Baur & Baur, ). There is experimental evidence that mites do not survive the long hibernation period of host snails in alpine sites (Haeussler et al ., ). In A. arbustorum , shell size as well as egg and clutch size decrease with increasing elevation (Baur, ; Baur & Raboud, ; Baur & Baur, ).…”

“…To examine the prevalence of parasitic mite infection, we dissected the snails and carefully checked their lung epithelium for the presence of mites and/or their eggs using a binocular microscope (for method see Haeussler et al ., ). To control for snail size, we measured the shell width of each individual to the nearest 0.1 mm using vernier callipers (the shell width of one individual could not be measured).…”

Morph-dependent nematode infection and its association with host movement in the land snail Cepaea nemoralis (Mollusca, Gastropoda)

“…One of the main differences between the present study and Dahirel et al (2021) is the collection date. While here snails were collected several weeks after the onset of spring activity and kept active throughout, in Dahirel et al (2021) 2020 for a species-specific possible counter-example), or mite infection in Arianta arbustorum (Haeussler et al, 2012). Aestivation also slows down parasite development in two smaller species of land snails (Theba pisana and Trochoidea seetzenii), and reduces parasite numbers in the latter (Solomon, Paperna & Matkovics, 1996).…”