Alex Weir

Laboulbeniales on beetles: host utilization patterns and species richness of the parasites

Fungi of the order Laboulbeniales are obligate ectoparasites that are easy to detect on the integument of their arthropod hosts. This apparency, and other characteristics that suit them for the role of ‘model’ group in the exploration of parasite biodiversity patterns, are discussed. Salient features of the general biology of these organisms are summarized and past patterns of species description reviewed. In recent years, much as in the fungi as a whole, roughly equal proportions of new species have been described from tropical and temperate regions. Comparison of the known Laboulbeniales mycobiotas of Europe, Asia and ‘tropical Asia’ reveals that most of the more significant parasite genera are more or less equally well represented in each region. Patterns of host utilization are also largely similar, with more than 50% of host species recorded from each region belonging to the two beetle families Carabidae and Staphylinidae. However, there are indications that parasite species that are not confined to a single host species have significantly broader geographical ranges than any of their hosts. The pattern of host utilization in the relatively fully-inventoried assemblage of beetles of a tropical forest in North Sulawesi is described, in terms of the taxonomic group membership, habitat affiliation and feeding biology of recorded hosts. On the basis of the Sulawesi dataset and other available data on host exploitation patterns at various spatial scales, we suggest that between 2 and 5%, i.e. between ca 40000 and ca 100000 of an estimated 2 million extant beetle species, are hosts of one or more species of Laboulbeniales. Known and predicted levels of host specificity imply that a global figure for Laboulbeniales species exploiting Coleoptera is likely to be between 10000 and 50000 species. A smaller number of Laboulbeniales species, probably no more than half the number associated with beetles, are to be found on other arthropod hosts. Ways in which these estimates might be refined are discussed.

New British Laboulbeniales

Twelve species of Laboulbeniales associated with beetles (Coleoptera) are reported from the British Isles for the first time: Hydrophilomyces hamatus, Asaphomyces tubanticus, Laboulbenia argutoris, L. marina, L. polyphaga, Autophagomyces falcatus, Stichomyces conosomatis, Euphoriomyces liodivorus, Rickia zanetti, Cantharomyces orientalis, Monoicomyces homalotae and M. nigrescens . The genus Drusilla (Staphylinidae) is reported as a new host for Monoicomyces homalotae and at the species level an additional six parasite-host associations are recorded. For each of the new British species diagnostic features are noted and the known geographic distributions and host ranges summarized.

Notes on the Laboulbeniales of Sulawesi. The genus Rickia

Seventeen species of Rickia are reported from Sulawesi. Five are described: R. corylophidorum, R. mammillata, R. pocadii, R. serrulata, and R. sphindidorum. The slime mould feeding beetle family Sphindidae is reported for the first time as host for a species of the Laboulbeniales and R. minuta is recorded for the first time from a beetle, this species previously being known to parasitize only mites. For each of the reported species a detailed description with information on the known geographical distribution and host range is presented along with illustrations and a key to identification.

Further records of Laboulbeniales from collections of British Coleoptera

Seventeen species of Laboulbeniales associated with beetles are reported from Great Britain. Fourteen of these constitute new British records: Acompsomyces stenichni, Botryandromyces heteroceri, Dimeromyces balazucii, Ecteinomyces trichopterophilus, Hydraeomyces halipli, Laboulbenia acupalpi, L. leisti, L. notiophili, L. cf. pseudomasei, L. thaxteri, Monoicomyces fragilis, Rhachomyces canariensis, Rickia hyperborea, and Teratomyces philonthi. Additionally, Idiomyces peyritschii, Misgomyces dyschirii, and Peyritschiella protea are reported from Great Britain for the first time since Thaxters original collection. The diagnostic features, known geographical distributions, and host ranges are summarized for the species described.

New species and records of Laboulbeniales from the subantarctic islands of New Zealand

Until now Rhachomyces kenodactyli Balazuc & W. Rossi has been the only species of Laboulbeniales known to occur on Coleoptera in the Bounty, Antipodes, Auckland, Campbell and Snares Islands, which lie 48° to 35° S. Four new species (Diphymyces depressus, Diphymyces leschenii, Laboulbenia subantarctica and Laboulbenia loxomeri) and five new records for the subantarctic (Cucujomyces phycophilus, Diphymyces penicillifer, Laboulbenia sp. 1, Rhachomyces sp. 1 and Teratomyces sp. 1) are reported, increasing the known number of taxa tenfold. An expanded geographic range for Rhachomyces kenodactyli is reported. A relatively high percentage (12%) of known beetle species in the subantarctic serve as hosts for Laboulbeniales. This host utilization rate is higher than that in tropical and north temperate regions. The high proportion of intertidal coleopteran taxa in the subantarctic fauna probably accounts for the greater number of host species utilized. Fungi on intertidal beetles (Omaliinae [Staphylinidae], Oopterus [Carabidae] and Kenodactylus audouini [Carabidae]) are known from many host individuals and collections, while those on terrestrial species are known from few, and in some cases, a single collection or host. The sporadic occurrence of some species encountered increases the likelihood that a few species of Laboulbeniales on Coleoptera probably remain undiscovered in the region.

Laboulbenia pterostichi and its allies

In an attempt to clarify the taxonomic status, geographical distribution and host relationships of Laboulbenia pterostichi and its close allies, especially in relation to the parasites found on European Pterostichini (Coleoptera, Carabidae), we have examined the type series and a wide range of material from the northern hemisphere. We conclude that the presence of L. pterostichi on European Carabidae is not confirmed and that most records are based on misidentifications of the variable species L. pseudomasei.

Laboulbeniales parasitic on British Diptera

A new combination Stigmatomyces burdigalensis is proposed for Fanniomyces burdigalensis , a species newly recorded for Great Britain. Fanniomyces copromyzae is treated as a synonym. Fanniomyces is reduced to synonymy under Stigmatomyces . Eight additional species of Stigmatomyces are also recorded as new to Great Britain: S. biformis, S. constrictus, S. crassicollis, S. ephydrae, S. geomyzae, S. hydrelliae, S. limosinae and S. trianguliapicalis . The previous reports of two other species, S. entomophilus and S. purpureus in Great Britain are discussed. Diagnostic features and the known geographic distributions and host ranges are summarized for all the species. A key to British species is presented.

Triainomyces, a new genus of Laboulbeniales on the pill-millipede Procyliosoma tuberculatum from New Zealand

A new genus of Laboulbeniales, Triaino- myces, is described and illustrated based on a single species, T. hollowayanus found parasitizing females of the pill-millipede Procyliosoma tuberculatum in New Zealand. Structure and development of the thallus of T hollowayanus is described and distinctive features are discussed. The new genus is placed in the subtri- be Peyritschiellinae of the Peyritschielleae although perithecial ontogeny is similar to that observed in members of the Laboulbenioideae.

The taxonomic status of Corethromyces bicolor from New Zealand, as inferred from morphological, developmental, and molecular studies

Due to the absence of antheridial characters in collected material the precise placement of Corethromyces bicolor has remained troublesome up until now. Recent re-examination of receptacular and appendage characters present in the holotype led to its transfer to the genus Mimeomyces. Fresh collections of this fungus have provided the opportunity to re-assess its taxonomic position. Based on a combination of morphological and molecular characters, this species is re-instated within the genus Corethromyces.

Two new species of Ilyomyces

Two new species of Ilyomyces parasitizing rove beetles of the subfamily Steninae in Sulawesi, Indonesia, are described and illustrated. The taxa are discussed in relation to the two previously known species of Ilyomyces from Europe and an emendation of the generic diagnosis is proposed in order to accommodate the new species.