Withdrawn resources: Rickia wasmannii shortens the lifespan of Myrmica scabrinodis (original) (raw)
Related papers
Journal of invertebrate pathology, 2015
The order Laboulbeniales (Fungi, Ascomycota) is a little-studied group of microscopic ectoparasites of invertebrates, mostly insects. The effects of Laboulbeniales species on their hosts are mostly unknown. Rickia wasmannii Cavara, 1899 is a common Laboulbeniales fungus occurring in Europe and is currently known to be a parasite of at least eight Myrmica ant species. R.wasmannii serves as a good model organism for Laboulbeniales-host interactions, as this species covers the host in a very high density, and infected host individuals can be easily collected in high numbers. The effect of R. wasmannii on the survival rate of its most common host species, Myrmica scabrinodis Nylander 1846, was therefore investigated in a laboratory experiment on an individual level. To enhance the results, environmental stresses were simulated by depriving infected and uninfected workers of water and food. The survival of individuals was recorded hourly until the death of the last individual. Infected s...
– Myrmecophilous arthropods and their manifold relations to host ants are interesting from an evolutionary perspective. Rickia wasmannii is an ectoparasitic fungus belonging to the Laboulbeniales order. Here, we show that inquiline mites can become infected by R. wasmannii, which was thought to be restricted to the genus Myrmica (Hymenoptera: Formicidae). This is the first report of R. wasmannii from an alternative host in another subphylum (Chelicerata). We also found immature fruiting bodies on a larva of Microdon myrmicae (Diptera: Syrphidae), which represents the first report of any Rickia species on flies. This fungus is capable of infecting alternative, unrelated host species as they co-occur in the ant nest ''microhabitat''. These observations provide direct evidence for ecological specificity in Laboulbeniales. The presence of R. wasmannii on inquilines in Myrmica ant nests suggests that the parasite may have adapted to the ant nest environment and is less dependent on acquiring specific nutrients from the hosts. However, the alternative cannot be excluded; these infections might also represent chance events if the fungus is incapable of fulfilling its life cycle. Résumé – Études sur les Laboulbeniales des fourmis Myrmica (III) : les Arthropodes myrmécophiles comme hôtes alternatifs de Rickia wasmannii. Les arthropodes myrmécophiles et leurs relations multiples avec leurs fourmis hôtes sont intéressants d'un point de vue évolutif. Rickia wasmannii est un champignon ectoparasite appartenant à l'ordre Laboulbeniales. Ici, nous montrons que les acariens inquilins peuvent être infectés par R. wasmannii, que l'on croyait limité au genre Myrmica (Hymenoptera : Formicidae). Ceci est le premier signalement de R. wasmannii chez un hôte différent dans un embranchement différent (Chelicerata). Nous avons également trouvé des fructifications immatures sur une larve de Microdon myrmicae (Diptera : Syrphidae), ce qui représente le premier signalement d'une espèce de Rickia sur une mouche. Ce champignon est donc capable d'infester des espèces hôtes non apparentées qui sont présentes dans le « microhabitat » des nids de fourmis. Ces observations fournissent la preuve directe de la spécificité écologique des Laboulbeniales. La présence de R. wasmannii sur des inquilins dans les nids des fourmis de genre Myrmica suggère que le parasite peut s'être adapté à l'environnement des nids de fourmis et est moins dépendant de l'acquisition de nutriments spécifiques des hôtes. Cependant, l'alternative ne peut être exclue : ces infections peuvent également représenter des événements accidentels si le champignon est incapable de finir son cycle de vie.
Parasite
Fungal species identities are often based on morphological features, but current molecular phylogenetic and other approaches almost always lead to the discovery of multiple species in single morpho-species. According to the morphological species concept, the ant-parasitic fungus Rickia wasmannii (Ascomycota, Laboulbeniales) is a single species with pan-European distribution and a wide host range. Since its description, it has been reported from ten species of Myrmica (Hymenoptera, Formicidae), of which two belong to the rubra-group and the other eight to the phylogenetically distinct scabrinodis-group. We found evidence for R. wasmannii being a single phylogenetic species using sequence data from two loci. Apparently, the original morphological description (dating back to 1899) represents a single phylogenetic species. Furthermore, the biology and host-parasite interactions of R. wasmannii are not likely to be affected by genetic divergence among different populations of the fungus,...
Ectoparasitic fungi Rickia wasmannii infection is associated with smaller body size in Myrmica ants
Scientific Reports
Parasitism-generated negative effects on ant societies are multifaceted, implying individual and colony-level responses. Though laboratory based evidence shows that the sublethal fungus Rickia wasmannii is responsible for physiological and behavioral responses that may negatively affect individual workers’ resilience and life expectancy in Myrmica ant workers, colony-level stress response to this parasite is largely unknown. Here, we focus on understanding of a long-term, colony-level effect of Rickia infection on Myrmica scabrinodis ant populations by tracking trait size-based changes. We collected worker specimens from infected and uninfected colonies from the same population in order to: (1) compare body size in response to parasitism, (2) assess the extent to which possible changes in size are associated with the severity of infection, and (3) investigate shifts in body size in response to infection over time by testing correlation of workers’ ages and sizes. We found that worke...