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Hesperomyces virescens on Harmonia axyridis
Scientific classification

Engler (1898)

The Laboulbeniales is an order of Fungi within the class Laboulbeniomycetes. They are also known by the colloquial name, beetle hangers, [1] or labouls. The order includes around 2,325 species [2] of obligate insect ectoparasites that produce cellular thalli from two-celled ascospores. Of the described Laboulbeniales, Weir and Hammond 1997 find 80% to be from Coleoptera and the next largest group to be the 10% from Diptera. [3] Recently, the genus Herpomyces , traditionally considered a basal member of Laboulbeniales, was transferred to the order Herpomycetales based on molecular phylogenetic data. [4] [5] Laboulbeniales typically do not kill their hosts, although they may impair host fitness if the parasite density is high.


Laboulbeniales form individual thalli, and lack vegetative hyphae. A thallus is attached to its host by a simple dark-colored foot cell, or a rhizoidal haustorium through which the fungus penetrates the exoskeleton of its host to draw nutrients from the hemolymph. [6] The external part of the thallus may form male structures (antheridia) or female structures (trichogynes and perithecia), or both. New infections are initiated when spores from the perithecia attach to a compatible insect host. Spore transmission can sometimes occur during insect copulation, which may account for the different site specificity sometimes observed in male and female hosts. These fungi do not grow apart from their hosts.

Foundational work on the Laboulbeniales was completed by the American mycologist Roland Thaxter (1858–1932), particularly in his five-volume, illustrated Monograph of the Laboulbeniaceae (Thaxter 1896, 1908, 1924, 1926, 1931).

Recent molecular phylogenetic work has shown that some taxa are complexes of multiple species segregated by host, for example Hesperomyces virescens. [7] The classification of the order Laboulbeniales follows Isabelle Tavares (1985) but several taxa in that system are polyphyletic. [8] [9]

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Ascomycota Division or phylum of fungi

Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of the Ascomycota are asexual, meaning that they do not have a sexual cycle and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewer's yeast and baker's yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.

Cladoniaceae Family of fungi

The Cladoniaceae are a family of lichenized fungi in the order Lecanorales. It is one of the largest families of lichen-forming fungi, with about 560 species distributed amongst 17 genera. The reindeer moss and cup lichens (Cladonia) belong to this family. The latter genus, which comprises about 500 species, forms a major part of the diet of large mammals in taiga and tundra ecosystems. Many Cladoniaceae lichens grow on soil, but other can use decaying wood, tree trunks, and, in a few instances, rocks as their substrate. They grow in places with high humidity, and cannot tolerate aridity.

Streblidae Family of flies

The Streblidae are a family of flies in the superfamily Hippoboscoidea, and together with their relatives the Nycteribiidae, are known as bat flies. They are winged or wingless ectoparasites of bats, and often have long legs. They appear to be host-specific, with different species of bat flies occurring only on particular species of bat hosts, sometimes with multiple species of flies sharing a host bat.

Laboulbeniomycetes Class of fungi

The Laboulbeniomycetes are a unique group of fungi that are obligatorily associated with arthropods, either as external parasites or for dispersal (Pyxidiophorales).

Arthoniales Order of fungi

The Arthoniales is the second largest orders of mainly crustose lichens, but fruticose lichens are present as well. The order contains around 1500 species, while the largest order with lichenized fungi, the Lecanorales, contains more than 14000 species.


The Baeomycetales are an order of mostly lichen-forming fungi in the subclass Ostropomycetidae, in the class Lecanoromycetes. It contains 8 families, 33 genera and about 170 species. As a result of molecular phylogenetics research published in the late 2010s, several orders were folded into the Baeomycetales, resulting in a substantial increase in the number of taxa.

Mycocaliciaceae Family of fungi in the order Mycocaliciales

The Mycocaliciaceae are a family of seven genera and about 90 species of fungi in the order Mycocaliciales.

Hydrophilomyces is a genus of fungi in the family Laboulbeniaceae. It was circumscribed by American mycologist Roland Thaxter in 1908. The genus contain 12 species.

<i>Psilolechia</i> Genus of fungi

Psilolechia is a genus of four species of crustose lichens. It is the only member of Psilolechiaceae, a family that was created in 2014 to contain this genus.

Everniopsis is a fungal genus in the family Parmeliaceae. It consists of a single species, the bark-dwelling lichen Everniopsis trulla, which occurs in Africa and South America.

Roland Thaxter American mycologist (1858–1932)

Roland Thaxter was an American mycologist, plant pathologist, botanist, and entomologist, renowned for his contribution to the insect parasitic fungi—Laboulbeniales. His college education was completed at Harvard, where he dedicated forty years to mycological and botanical research. His five-volume series on fungi in the order Laboulbeniales laid a solid foundation of research on these insect ectoparasites. He also contributed to the field of Plant Pathology.


Amoebidiidae is a family of single-celled eukaryotes, previously thought to be zygomycete fungi belonging to the class Trichomycetes, but molecular phylogenetic analyses place the family with the opisthokont group Mesomycetozoea. The family was originally called Amoebidiaceae, and considered the sole family of the fungal order Amoebidiales that included two genera: Amoebidium and Paramoebidium. However, Amoebidiidae is now monogeneric as it was recently emended to include only Amoebidium. Species of Amoebidium are considered obligate symbionts of freshwater-dwelling arthropod hosts such as midge larvae and water fleas (Daphnia). However, because Amoebidium species attach to the exoskeleton (exterior) of the host and grow in axenic culture, at least some species may be facultative symbionts.

Rickia wasmannii is a species of the widely distributed entomoparasitic order of fungi Laboulbeniales. It is an obligatory ectoparasite of ants of the genus Myrmica. The thalli penetrate outer layer of the cuticle, and appear on the host body surface. Little is known about its effect on the host ant, but it is usually regarded as a rather neutral symbiont. Contrarily, however, a recent study has documented an increased need of drinking water and a shortened life-span of infected ants.

Lepidostromatales Order of fungi

Lepidostromatales is an order of fungi in the class Agaricomycetes. It is the only known order of basidiomycete fungi composed entirely of lichenized members. Morphologically, the fruiting bodies of all species are clavarioid. Six species are known, five of which were described within the span of 2007–2013. Due to its morphological similarity to the genus Multiclavula, its isolated phylogenetic position was not understood until quite recently. The photobionts that have been found in association with members of this group are not known to associate with any other types of lichenized fungi.

Cryptandromyces elegans is a species of fungi in the family Laboulbeniaceae. It is found in the Netherlands.

Herpomyces is a fungal genus in the order Herpomycetales (Laboulbeniomycetes), with species that are exclusively ectoparasites of members of the Blattodea order (cockroaches). As of 2020, 27 species of Herpomyces are formally described. Members of Herpomyces have been reported from all continents except Antarctica.

<i>Amoebidium</i> Genus of eukaryotes

Amoebidium is a genus of unicellular, symbiotic eukaryotes in the Opisthokont group Mesomycetozoea, family Amoebidiidae. Amoebidium species attach to the exoskeleton of freshwater aquatic arthropods such as midge larvae and water fleas (Daphnia). The type species is Amoebidium parasiticum, which is also one of the only species to be cultured axenically.

Paramoebidium is a genus of unicellular, symbiotic eukaryotes that inhabit the digestive tract of immature freshwater arthropod hosts. Paramoebidium is classified in the opisthokont class Mesomycetozoea, and is the sole genus in the family Paramoebidiidae. Prior to 2005, Paramoebidium species were tentatively placed with the fungal group Trichomycetes due to their habitation of arthropod guts, host overlap between various Paramoebidium and fungal trichomycete taxa, and similar vegetative growth form.

Herpomycetales Order of fungi

The Herpomycetales is an order of fungi within the class Laboulbeniomycetes. The order includes a single dioecious genus, Herpomyces, with 27 accepted species of obligate ectoparasites that are associated exclusively with cockroaches. Like the Laboulbeniales order, they produce cellular thalli. However, the thalli of Herpomyces are developmentally and morphologically unique.

Toensbergia is a genus of lichen-forming fungi in the family Sporastatiaceae. The genus was circumscribed by Mika Bendiksby and Einar Timdal in 2013. The genus name honours Norwegian lichenologist Tor Tønsberg, "in appreciation of his important work on sorediate, corticolous lichens". The type species is Toensbergia leucococca, which was formerly classified in genus Hypocenomyce, presumably due to its resemblance to Hypocenomyce xanthococca.


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  2. Kirk, Paul (2019). "Catalogue of Life".
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  6. Tragust, Simon; Tartally, András; Espadaler, Xavier; Santamaria, Sergi (2016). "Histopathology of Laboulbeniales (Ascomycota: Laboulbeniales): ectoparasitic fungi on ants (Hymenoptera: Formicidae)". Myrmecological News. 23: 81–89.
  7. Haelewaters D, De Kesel A, Pfister DH (2018). "Integrative taxonomy reveals hidden species within a common fungal parasite of ladybirds". Scientific Reports. 8 (1): 15966. Bibcode:2018NatSR...815966H. doi:10.1038/s41598-018-34319-5. PMC   6206035 . PMID   30374135.
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  9. Haelewaters D, Page RA, Pfister DH (2018). "Laboulbeniales hyperparasites (Fungi, Ascomycota) of bat flies: Independent origins and host associations". Ecology and Evolution. 8 (16): 8396–8418. doi:10.1002/ece3.4359. PMC   6145224 . PMID   30250711.

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