Marvin C. Williams

Tasmanian Trichomycete gut fungi in aquatic insect larvae.

A fourth species of the Australasian genus Austrosmittium, A. biforme (Trichomycetes, Harpellales), has been found. This gut fungus from Chironomidae larvae collected in a Tasmanian stream has the unusual feature of producing two distinctly different sizes of trichospores. Two new Tasmanian species of the more common genus Smittium, S. compactum and S. fastigatum, are described from lotic chironomid larvae. A new species of Harpellales from Tasmanian mayfly nymphs is also described and illustrated, but not named; it may represent a new genus that has similarities to Bojamyces repens recently described from the USA. New records of other Tasmanian trichomycetes from aquatic insects are provided.

Two unusual Trichomycetes in an aquatic midge larva

Description et diagnose latine de 2 especes nouvelles: Smittium dimorphum sp. nov. et Stachylina pedifer sp. nov.

Three new species of Smittium (Trichomycetes) with notes on range extensions

Three new species of Smittium (Harpellales) are described from the hindguts of dipteran larvae collected near Gothic, Colorado. Smittium perforatum, from Chironomidae, is the second species of the genus known to penetrate the gut cuticle. Smittium coloradense was dissected from chironomids and possibly from simuliids. Tipulid larvae are the hosts for S. tipulidarum, which was cultured axenically. The range of S. pusillum and S. typhellum is extended from France to the United States.

Western Australian species of Smittium and other Trichomycetes in aquatic insect larvae

Three species of Smittium (Trichomycetes, Harpellales) that may be endemic to Western Australia are described from the hindguts of midge larvae (Diptera, Chironomidae): S. fruticosum, S. angustum and S. microsporum. Axenic cultures were obtained of the latter two fungal species. The occurrence in Western Australia of six geographically widespread species of other Harpellales from dipteran guts is reported together with records of Paramoebidium spp. (Amoebidiales) in Chironomidae and Ephemeroptera.

A new Legeriomyces (Harpellales) with variable trichospore size

ABSTRACTLegeriomyces aenigmaticus, a new species of a previously monotypic genus, produces trichospores which fall into three class sizes. It is known only from one stream in northwestern Montana, ...

Ejectosporus, an unusual new genus of Harpellales in winter-emerging stonefly nymphs (Capniidae) and a new species of Paramoebidium (Amoebidiales)

Ejectosporus magnus belongs to a new monotypic genus of Harpellales (Trichomycetes) found in the hindgut of Allocapnia spp. nymphs (Plecoptera, Capniidae). The mature sporangiospore is forcefully e...

TWO STACHYLINA AND TWO SMITTIUM SPECIES (TRICHOMYCETES) FROM MONTANA

Four new species of Harpellales are described from the midgut and hindgut of aquatic Diptera larvae: Stachylina manicata and Stachylina lotica (Harpellaceae), and Smittium gigasporus and Smittium ouseli (Legeriomycetaceae). Stachylina lotica is the first Harpellales reported from Psychodidae; the other three were found in Chironomidae. Stachylina manicata was collected in a cattail swamp, whereas the other species were taken from clear mountain streams. Stachylina species are found attached to the peritrophic membrane in the midgut region of dipteran larvae (usually Chironomidae). They are characterized by having unbranched, holocarpic thalli whose trichospores, with or without a collar, produce a single appendage; zygospores are unknown in this genus. Smittium species are found in the hindgut of dipteran larvae (Ceratopogonidae, Chironomidae, Culicidae, and Simuliidae). They are branched and produce trich? ospores with a collar and a single appendage. Species known to reproduce sexually produce biconical zygospores with a collar and a single appendage. Stachylina manicata Williams & Lichtwardt, sp. nov. Figs. 1-4 Thalli ad 100 ^m longi, 6.5-8 pm diametro, a retinaculo simplici, quam thallus tenuiore, ad membranam peritrophicum larvarum Chironomidarum affixi, usque ad 8 trichosporas ellipsoidales vel subconicas 17.5-20 x 4-5 /xm, collari parvo instar manicae 1-1.5 x 0.5 ^m praeditas, gignentes. Zygosporae ignotae. Mature thalli up to 100 /xm long x 6.5-8 ixm diam, producing up to 8 trich? ospores, attached to the peritrophic membrane of Chironomidae larvae by a simple disk-like holdfast with a smaller diam than the thallus. Trichospores ellipsoidal to sub-biconical, 17.5-20 x 4.5 fxm, with a small sleeve-like collar 1-1.5 x 0.5 ixm surrounding the single appendage which narrows toward the distal end and is generally at least 5 times the length of the spore. Generative cell usually shorter than the trichospore. Zygospores unknown.

BIOGEOGRAPHIC STUDIES ON TRICHOMYCETE GUT FUNGI IN WINTER STONEFLY NYMPHS OF THE GENUS ALLOCAPNIA

Winter stoneflies of the genus Allocapnia (Plecoptera, Capniidae) have low vagility, and apparently first evolved in the Appalachian system from where they slowly dispersed and speciated at different times during the Pleistocene. Five described genera and species of Harpellales (Trichomycetes) live in the aquatic nymphs of Allocapnia. Two of these, Genistelloides hibernus and Simuliomyces spica, were found widely distributed in 53 stream sites in nine states that include the western and southern dis? tribution limits of Allocapnia spp. This suggests that the fungi had already evolved in Allocapnia nymphs before major radiation pulses of the stoneflies during the Pleistocene. Two other fungi, Ejectosporus magnus and Capniomyces stellatus, were more limited in their distribution and might have evolved subsequent to early Allocapnia dispersals. One species, Orphella hiemalis, may be endemic to the Ozark Plateau and Ouachita Mountains. The presence of different extant species of Genistelloides and Orphella in the stonefly faunas of North America and Europe indicates that species of those two genera of fungi must have existed prior to the final separation of the two continents during the Lower Eocene. Isozymes were extracted and electrophoresed from 25 axenic cultures of G. hibernus obtained from six states. When grouped by geographic region, the greatest coefficient of similarity among fungal isozyme phenotypes was between the Ozarkian isolates and those from northeastern Texas. However, the similarities between central Tennessee and Kansas were greater than they were between eastern Tennessee and Alabama. This apparent disparity might be explained biogeographically by a southwestward Pleistocene dispersal into Alabama of G. hibernus-infested Allocapnia populations originally located between the Cumberland Plateau and the mountains to the east, and a separate westward dispersal of other pop? ulations of fungus-infested stoneflies that were situated to the west of the Cumberland Plateau. The isozyme data also suggest that G. hibernus may have moved with its hosts from northern Alabama into the Ozark Plateau.

TWO NEW AUSTRALASIAN SPECIES OF AMOEBIDIALES ASSOCIATED WITH AQUATIC INSECT LARVAE, AND COMMENTS ON THEIR BIOGEOGRAPHY

The Amoebidiales, traditionally included in the fungal class Trichomycetes, consists of two genera (Paramoebidium and Amoebidium) and six valid species associated with freshwater crustaceans and insect larvae. Some of these commensals are common and generally widespread. A new species Paramoebidium papillatum is described from the hindgut of Siphlonuridae mayflies in New Zealand streams. The only other known New Zealand species P. bibrachium is closely allied and is found in Leptophlebiidae mayflies. The genus Paramoebidium is apparently rare in New Zealand but common in Australia. The only species of Amoebidium found in Australia and New Zealand to date is the new species A. australiense; it lives commensalistically on the external cuticle of a species of bloodworm (Chironomidae) in Western Australia. The biogeography of the Amoebidiales in Australia and New Zealand is discussed.

Discovery of Sexual Reproduction in an Unusual New Species of Stachylina (Trichomycetes)

N. thaiana are 13-25 x 13.5-23 ,um, between those of N. heterophragmae (14-27 x 16.5-26 gm) and N. kigeliae (17-26 x 14-20 um), and teliospore walls of N. thaiana (1-2 ,um) are thinner than those of N. heterophragmae (2-3 Mum) and N. kigeliae (2 um). Mundkur and Thirumalachar (1945) reported Mehtamyces stereospermi (Mund.) Mund. et Thir. [=Phragmidiella stereospermi (Mund.) Mund. et Thir.] on Stereospermum suaveolens Wall. from India. However, this species is different from N. thaiana in uredinial and telial morphology.