Laboulbenia slackensisandL. littoralissp. nov. (Ascomycota, Laboulbeniales), two sibling species as a result of ecological speciation

Abstract

The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters. Abstract: Laboulbenia littoralis is described from the halobiont Cafius xantholoma (Coleoptera, Staphylinidae); it previously was misidentified and not properly documented. Morphologically the new species belongs to a group of carabidicolous taxa similar to Laboulbenia pedicellata and especially Laboulbenia slackensis. It is generally accepted that the specificity of Laboulbeniales is based on their need for substances from the host. In this relatively strict context, shifts between unrelated hosts are difficult to explain. We present morphological and ecological evidence supporting the hypothesis that these fungi are capable of shifting between unrelated hosts as long as they share the same habitat. Adaptation to a particular environment, combined with a reduced dependence from specific nutrients of the host, explains the proposed interfamilial host shift.

Studies of Laboulbeniales (Fungi, Ascomycota) on Myrmica ants: Rickia wasmannii in the Netherlands

“…Host shifts have been suggested for morphologically similar Laboulbenia species between Cicindelinae and other Car- abidae living in the same habitat (Arndt et al 2003, Rossi 2011), and De Kesel and Haelewaters (2014 provide morphological and ecological data to support the hypothesis that a species of Laboulbenia shifted between Carabidae and Staphylinidae. To explain the extremely small size of Rickia lenoirii on Messor spp.…”

A new species of Speonemadus from Portugal, with the revision of the escalerai-group (Coleoptera, Leiodidae)

“…This fungus species has only been previously found in Staphylinidae beetles of the genus Sepedophilus Gistel, 1856 (Haelewaters et al 2015), that was also found in these caves (Reboleira unpublished). The remarkable discovery of this Laboulbeniales species on a new host of the family Leiodidae is the first case of host shifting following an ecological opportunity (sensu De Kesel & Haelewaters 2014), in the subterranean environment. Also phoretic undetermined mites were observed on some specimens (Fig.…”

Studies of Laboulbeniales onMyrmicaants (III): myrmecophilous arthropods as alternative hosts ofRickia wasmannii

“…Host shifts are probably an important driving force of speciation among Laboulbeniales fungi [11], as certain morphologically similar species are associated with phylogenetically unrelated hosts. For example, Laboulbenia davidsonii W. Rossi was described from cicindeline hosts (Coleoptera: Carabidae: Cicindelinae), although it is obviously related to a group of species parasitic on Galerita spp.…”

“…These hosts, however, are both halobiont, salt marsh-inhabiting species and occur in close proximity to seaweed and plant debris. Morphological and ecological evidence supported that a host shift between these unrelated but co-occurring hosts had happened, leading to reproductive isolation of populations (on these different hosts), changes in morphology, and speciation [11]. …”

“…Second, plurivory could ultimately lead to (ecological) speciation by reproductive isolation, since the different populations may be using different nutritional resources and environments. It has been suggested that specific nutrients of co-habiting hosts (or, alternatively, nutrients available from the hosts’ environment) may be far more important for Laboulbeniales species associated with multiple hosts than the identity of the insect hosts [3, 11, 37]. The best-known example of a Laboulbeniales species with multiple diverse host groups is L. ecitonis , reported in Brazil [7], Costa Rica [27], Ecuador [29], and Panama (Haelewaters, unpublished data).…”