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

     Faculty of Environmental and Forest Biology, 1 Forestry Drive, 350 Illick Hall, State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 

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.

Key words: Corethromyces, Laboulbeniales, Mimeomyces, Sphaleromyces, taxonomy

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 
Although Laboulbeniales have been the subject of increased attention in recent years, they are still largely unknown with regard to their nutrition, pathogenicity, and even general taxonomy. Based upon a detailed comparison of samples of arthropods from Indonesia and the United Kingdom, Weir and Hammond (1997) arrived at a global figure for Laboulbeniales that exploit Coleoptera only to be between 10 000 and 50 000 species. Currently there are 1855 described species on all host groups of arthropods (Hawksworth et al 1995 ), indicating that only a small fraction of the potential global diversity of this order is currently known.

Relative to other large groups of fungi, the consistency and stability of taxonomic concepts within the order is quite impressive, due largely to the thoroughness and extent of Thaxter's publications (1896, 1908, 1924, 1926, 1931) . Despite this, a number of unresolved taxonomic problems remain. For example, in erecting the genus Corethromyces Thaxt., Thaxter (1892) noted the ‘highly differentiated appendages' that characterized the type species C. cryptobii Thaxt. Within a few years, however, and with the addition of new taxa, the generic limits became increasingly expansive (Thaxter 1908 ) until a state of confusion was eventually reached (Thaxter 1912, 1931 ). Thaxter had much difficulty reconciling the generic placement of a relatively small subset of taxa for which antheridial characters were largely lacking. At one time or another these taxa were assigned to Corethromyces, Sphaleromyces Thaxt. (Thaxter 1894 ) or Mimeomyces Thaxt. (Thaxter 1912 ).

One problematic species, Corethromyces bicolor Thaxt. (Fig. 1 ), was first described based on collections from Auckland, New Zealand, on the legs and inferior surface of the abdomen of "Choleva" sp. (Coleoptera, Leiodidae) (Thaxter 1918 ). Thaxter's examination of immature thalli revealed no antheridia. His decision to place this fungus in Corethromyces, a genus characterized by seriate, simple, intercalary or free antheridia, was instead based upon other vegetative characters such as the extensive branching of the appendage.

View larger version (71K): [in this window] [in a new window]    FIG. 1. Diagrammatic representation of various stages in the development of the type a thallus of C. bicolor. a) Pair of two-celled ascospores with cross walls (a). b) Sporeling with developed foot and terminal spine. c–f) Immature thalli with darkened cell I, flattened cell II, and perithecial initial (d). g) Immature thallus showing early stages of perithecial differentiation including the lower cell formed by division of cell d (h), the carpogonial cell (cp), and an upper cell (e). h) Immature thallus showing simple, seriate intercalary antheridia (an) and early development of outer wall cells of perithecium. Note also the products of division of cell e, a lower trichophoric cell (tc), and a damaged or aborted trichogyne (tr). i) Immature thallus with upper lobe unshaded to show arrangement of upper receptacular cells (II, III, III'), formation of antheridia (an), and further development of the perithecium including differentiation of secondary stalk cell (VII), basal cells (n, n'), and lower outer wall cells (w1, w2). Note also as yet undivided upper wall cell (o) and trichogyne scar (tr). j) Immature thallus with upper lobes unshaded. Note numerous seriate, simple, intercalary antheridia (an), first outer wall cell of perithecium (o), trichophoric cell (tc) and undamaged, septate, filamentous trichogyne (tr). k) Mature thallus with upper lobe unshaded and slightly squashed. Note arrangement and pigmentation of perithecial basal cells (n, n') and four distinct tiers of perithecial wall cells (w1–w4), one of which forms a protruding papilla at the apex of the perithecium. Scale bars = 10 µm. FIGS. 1a–f = Scale bar B. FIGS. 1g–k = Scale bar A

View larger version (142K): [in this window] [in a new window]    FIGS. 2–5. FIG. 2. SEM showing C. bicolor thalli (type a) on the abdomen of the host. Scale bar = 20 µm. FIG. 3. SEM illustrating type a thalli of C. bicolor with four outer wall cell tiers (w). Scale bar = 50 µm. FIG. 4. Light micrograph of immature thallus of C. bicolor with seriate, simple, intercalary antheridia (an). Scale bar = 10 µm. FIG. 5. Light micrograph of immature thallus of Mimeomyces decipiens with two distinct compound antheridia (an). FH 2091. Scale bar = 10 µm

Here, as part of our on-going work on the Laboulbeniales of New Zealand, we present new morphological and molecular data arising from fresh collections of C. bicolor that conflict with the current placement of this fungus in the genus Mimeomyces. The use of perithecial and antheridial characteristics for classification in Mimeomyces and Corethromyces is also addressed.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 
Collection of hosts – Host insects were collected using standard entomological techniques by G Hall, E Hilario, R Hoare, and RAB Leschen (Landcare Research, Auckland, New Zealand), CE Carlton (Louisiana State University) and A Weir (SUNY College of Environmental Science and Forestry). Collected insects were stored in 75% ethanol for transport to the laboratory.

Light microscopy – Permanent microscopic preparations of thalli of C. bicolor were made as outlined by Benjamin (1971, 1986) and observations, drawings, and photomicrographs were made with a Nikon E-800 research microscope fitted with DIC optics. Over 900 thalli at various stages of development were examined. In addition, we obtained on loan from the Farlow Herbarium (FH) all of the extant Thaxter type material for C. bicolor as well as the type and other material of selected taxa described by Thaxter in the genera Corethromyces or Sphaleromyces and now placed in Mimeomyces. For some of these collections additional isotype material was obtained from the Mycology Collections at the Royal Botanic Gardens, Kew, UK [K(M)]. The original hosts of C. bicolor were also received on loan from the Museum of Comparative Zoology, Harvard University.

Specimens examined.—Corethromyces bicolor: NEW ZEALAND. North Island: Auckland, on the legs and inferior abdomen of Mesocolon alacre (Broun) (Coleoptera, Leiodidae), Eames and Sinnott, HOLOTYPE FH #4319. Same collection and host data as above, ISOTYPES FH #4320–4321. NEW ZEALAND. North Island. Northland, Puketi State Forest, on M. alacre, 31 Mar–3 May 1999, (Flight Intercept Trap), RAB Leschen, G Hall, and R Hoare, CL 400. North Island. Northland, Puketi State Forest, on Mesocolon alacre (Coleoptera, Leiodidae), 31 Mar–3 May 1999, (Flight Intercept Trap), RAB Leschen, G Hall, and R Hoare, CL 401. North Island. Northland, Puketi State Forest, on M. alacre, 4 May–13 Jun 1999, (Flight Intercept Trap), RAB Leschen and E Hilario, CL 428. North Island. Northland, Waipoua State Forest, Yakas Track, on M. alacre, 29 Mar–5 May 1999, (Flight Intercept Trap), RAB Leschen, G Hall, and R Hoare, CL 410. North Island. Coromandel Region, Coromandel, Mt. Moehau Track, on Mesocolon alacre (Coleoptera, Leiodidae), 11 Apr 1999, (Sifted Leaf Litter), RAB Leschen and E Hilario, CL 384. North Island. Bay of Plenty Region, Kaimai-Mamaka Forest Park, on Mesocolon alacre (Coleoptera, Leioididae), 27 Mar 2000, (Pitfall Trap), C Carlton and A Weir, CL 091. North Island. Gisborne, Whirinaki Forest Park, end of Okahu Road, on M. alacre (Coleoptera, Leiodidae), 23 Mar 2000, (Pitfall Trap), C Carlton and A Weir, CL 084. North Island. Gisborne, Urewera National Park, N of Hopuruahine Stream at junction with State Highway 38, on Paracatops sp. 1 and M. alacre (Coleoptera, Leiodidae), 23 Mar 2000, (Flight Intercept Trap), C Carlton and A Weir, CL 081. North Island. Gisborne, Urewera National Park, N of Hopuruahine Stream at junction with State Highway 38, on Mesocolon sp. 2 (Coleoptera, Leiodidae), 23 Mar 2000, (Pitfall Trap), C Carlton and A Weir, CL 082. North Island. Gisborne, Urewera National Park, Aniwaniwa Visitor Centre, near Aniwaniwa Stream, on Mesocolon alacre (Coleoptera, Leiodidae), 23 Mar 2000, (Flight Intercept Trap), C Carlton and A Weir, CL 079. North Island. Gisborne, Urewera National Park, Aniwaniwa Visitor Centre, near Aniwaniwa Stream, on Mesocolon alacre and Mesocolon sp. 3 (Coleoptera, Leiodidae), 23 Mar 2000, (Pitfall Trap), C Carlton and A Weir, CL 080. North Island. Gisborne, Urewera National Park, Ngomoko Track, on Paracatops sp. 1 (Coleoptera, Leiodidae), 22 Mar 2000, (Flight Intercept Trap), C Carlton and A Weir, CL 077. North Island. Tongariro Region, Tongariro National Park, near Ohakune, Mt. Ruapehu, on Mesocolon sp. 1 (Coleoptera, Leiodidae), 25 Mar 2000, (Flight Intercept Trap), C Carlton and A Weir, CL 087. North Island. Taranaki Region, Moki Forest Conservation Area, on Mesocolon sp. 1, Paracatops sp. 1, and Paracatops nr sp. 1 (all Coleoptera, Leiodidae), 26 Mar 2000, (Flight Intercept Trap), C Carlton and A Weir, CL 088. South Island. Nelson Region, Lyell Walk, on Leiodidae indet, 8–19 Feb 1999, (Flight Intercept Trap), RAB Leschen and R Hoare, CL 339. South Island. Marlborough Region, Pelorus Bridge, on Paracatops sp. 1 (Coleoptera, Leiodidae), 15–20 Nov 1999, (Flight Intercept Trap), RAB Leschen, CL 503. South Island. North Canterbury, Craigieburn State Forest, Dracophyllum Flat Trail, on Mesocolon sp. 4 and M. alacre (Coleoptera, Leiodidae), 10–27 Jan 1998, C Carlton and RAB Leschen, CL 150. South Island. Otago Lakes, 10.5 km NW Glenorchy, on Paracatops nr sp. 1 and Paracatops sp. 2 (Coleoptera, Leiodidae)., 14–24 Jan 1998, (Flight Intercept Trap), C Carlton and RAB Leschen, CL 143. South Island. Westland, Fox Glacier, on Leiodidae indet., (Flight Intercept Trap), 16–25 Jan 1998, C Carlton and RAB Leschen, CL 144.

—Corethromyces spectabilis Thaxt.: SIERRA LEONE. Western Area, Picket Hill, on the tergites of Sepedophilus sp., 1 Nov 1995, W Rossi, SYRF AW-668A.

—Mimeomyces andinus (Speg.) Thaxt.: CHILE. Corral, on Quedius impressifrons Solier, Dec 1905, R Thaxter #1522, FH #2064–2070. CHILE. Concepción, on the abdomen of Quedius sp., Nov 1905, R Thaxter #1467, FH #2063.

—Mimeomyces atropurpureus (Thaxt.) Thaxt.: PANAMA. Volcan de Chiriquí, on the abdomen of Quedius graciliventris Sharp, host in Biologia Collection, British Museum, R Thaxter #740, HOLOTYPE FH #2072. Same collection and host data as above, ISOTYPES FH #2074, K(M) #8794. PANAMA. Volcan de Chiriquí, on the abdomen of Q. basiventris Sharp, host in Biologia Collection, British Museum, R Thaxter #741, FH #2073.

—Mimeomyces brachydiri (Thaxt.) Thaxt.: PERU. On the legs and abdomen of Nordus antennatus (Sharp), HOLOTYPE FH #2076. Amazon, on the abdomen of N. antennatus, R Thaxter #773, 1155, FH #2077–2081.

—Mimeomyces chiriquensis (Thaxt.) Thaxt.: PANAMA. Volcan de Chiriquí, on the abdomen of Quedius flavicaudus Sharp, R Thaxter #1157, HOLOTYPE FH #2083. Same collection and locality data as above, ISOTYPES FH #2084–2086, K(M) 8793.

—Mimeomyces decipiens: ARGENTINA. Buenos Aires, Llavallol, Santa Catalina, on the legs of Quedius sorecocephalus Bernhauer (nomen invalidum), Mar 1906, R. Thaxter #1520, HOLOTYPE FH #2088. Same collection and host data as above, ISOTYPES FH #2089–2091.

—Mimeomyces deplanatus I. I. Tav.: ARGENTINA. Buenos Aires, Llavallol, Santa Catalina, on the abdomen and legs of Quedius sorecocephalus Bernhauer (nomen invalidum), Apr 1906, R Thaxter #1520a, HOLOTYPE FH #2310. Same collection and host data as above, ISOTYPES FH #2306–2309, 2311–2312.

—Mimeomyces latonae (Thaxt.) Thaxt.: on the legs of Pseudocryptobium spinolae Guérin, host in Berlin Museum, R Thaxter #834, HOLOTYPE FH #2093. Same collection and host data as above, ISOTYPES FH #2094–2096.

—Mimeomyces quedionuchi (Thaxt.) Thaxt.: San Andrés, on the abdomen of Quedius impunctus de Solsky, R Thaxter #1105, HOLOTYPE FH #2301. Same collection and host data as above, ISOTYPES FH #2302–2305.

—Mimeomyces valdivianus (Thaxt.) Thaxt.: on the abdomen of Quedius impressifrons Solier, Dec 1905, R Thaxter #1522, HOLOTYPE FH #2316. Same collection and host data as above, ISOTYPES FH #2314–2315, 2317.

—Sphaleromyces lathrobii Thaxt.: Baton Rouge Parish, Bluebonnet Swamp Nature Reserve, on the abdomen of Staphylinidae indet., 16 May 1998, A Weir, SYRF AW-822.

Scanning electron microscopy (SEM) – For examination of thalli using scanning electron microscopy, infected beetles were brought to 100% ethanol via a graded ethanol series. The dehydrated samples were then air-dried from tetramethlysilane. Beetles were then mounted onto aluminum stubs and gold-shadowed in a sputter coater. Specimens were observed on a JEOL 5800 LV scanning electron microscope operated between 5 and 7 kV.

DNA extraction, amplification, and sequencing – Five thalli were crushed for DNA extraction following the protocols of Weir and Blackwell (2001) . Primers NS1 and NS4 (White et al 1990 ) were used for amplifying SSU rDNA by the polymerase chain reaction (PCR) with PCR conditions following those given by Weir and Blackwell (2001) . The PCR product was cleaned with a Prep-a-Gene Kit (Bio-Rad, Hercules, California). Purified double-stranded PCR products were used directly as templates for sequencing with an ABI PRISM Dye Terminator Cycle sequencing kit (PE Applied Biosystems, Foster City, California). NS2, NS3 primers (White et al 1990 ) were used in sequencing. The rDNA sequence was determined by an ABI PRISM 310 Genetic Analyzer (PE Applied Biosystems, Foster City, California).

Data analysis – The partial 18S rDNA sequence for C. bicolor (GenBank Ref. #AF431762) was aligned and optimized visually in comparison with sequences from nine other Laboulbeniales: Botryandromyces ornatus (GenBank Ref. #AF431760), Ceratomyces mirabilis (AF431764), Corethromyces sp. (AF431761), Rhachomyces philonthinus (AF431756), Rhadinomyces pallidus (AF431763), Rickia passalina (AF432129), Stigmatomyces hydrelliae (AF431757), S. rugosus (AF431759), S. scaptomyzae (AF431758), and one outgroup taxon, Aureobasidium pullulans (de Bary) Arn., obtained from GenBank (Ref #M55639). Ambiguous regions were excluded from the analyses. Maximum parsimony analyses were performed using PAUP4.059B (Swofford 1999 ). Heuristic tree searches were executed using the tree bisection-reconnection branch-swapping algorithm with random sequence analysis. Support for internal branches within the resulting tree was obtained by bootstrap analysis (Felsenstein 1985 ) from 1000 replications.

	RESULTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 
Light microscopy, scanning electron microscopy, and fungal development – Clumps of thalli of C. bicolor were easily seen on the integument of the host using both light microscopy and SEM (Fig. 2 ). Two thallus types were observed, one with a distinctly tri-lobed cell I (type a, Figs. 2, 3 ), the other with this melanized region entire and undivided (type b, not shown). Each of the two reported host genera supported both type a and type b thalli. Like all known Laboulbeniales, the ascospore of C. bicolor is two celled (Fig. 1a ). The cross-wall (a) (Fig. 1a ) is submedian and the hyaline sheath surrounding the body of the ascospore is thinner around the shorter segment. The gelatinous sheath facilitates attachment of the longer cell to the host integument as the germinating ascospore continues to elongate and broaden. The lower end of the basal (longer) segment differentiates and forms the foot (fo). The tip of the upper segment hardens and forms a spinose process (spi) (Fig. 1b ).

The receptacle consists of a long basal cell (I) arising from a subdivision of the larger ascospore segment (Fig. 1c ), which along with the foot cell, is heavily melanized. Cell I is superposed by a flattened cell II (Fig. 1c ), the latter subdividing and forming an upper cell (III) (Fig. 1j ) and a perithecial initial (d) (Fig. 1c, d, e ). Cell III subdivides and forms an appendage branch but is also superposed by cell III' (Fig. 1i ). The latter produces a cluster of secondary appendage branches (Fig. 1i–k ). The stalk cell of the perithecium (VI) gives rise to a secondary stalk cell (VII), which in turn supports the basal cells of the perithecium (Figs. 1h–j cells m (not shown), n, n').

Simple antheridia (an) are frequently present in immature thalli (Figs. 1h–j, 4 ). These intercalary and seriate antheridia are most often found on the inner appendage branches that appear to arise directly from cell III of the receptacle. No compound antheridia were observed in the numerous specimens of immature thalli of C. bicolor examined in this study.

The perithecial initial (d) arises directly from cell II (Fig. 1c, d, e ), divides and gives rise to the primordial cell of the perithecium (h) (Fig. 1g ) and the primordial cell of the procarp (not shown). The latter divides further and forms the carpogonial cell (cp) below and cell e above (Fig. 1g ). Cell e eventually gives rise to the trichophoric cell (tc) below and the young trichogyne (tr) above (Fig. 1h, j ). While the first outer wall cells (o) are developing from the three basal cells (only two shown, n, n'—Fig. 1i, k ), the trichogyne continues to grow (Fig. 1h, j ). Further perithecial development is similar to that reported in other Laboulbeniinae. Intact trichogynes were observed in only a very few specimens (Fig. 1j ) with most of the immature thalli either lacking any trichogyne development, or displaying a damaged or broken trichogyne. The undamaged trichogyne consists of a long, septate filament (Fig. 1j ). Presumably following fertilization the trichogyne degenerates, being absent in more mature thalli and represented by a surface scar (Fig. 1i, k ), and the perithecial wall cells extend upward and around the female apparatus. The mature perithecium consists of four cells in each vertical row of outer wall cells, of which there are four (Figs. 1k, 3 ). The perithecial apex is distinctive with one of the two wall rows derived from basal cell n forming a protruding papilla (Fig. 1k ).

Comparison with other taxa examined – Corethromyces bicolor shares a similar overall thalloid morphology with taxa currently placed in the genera Corethromyces, Mimeomyces, and Sphaleromyces. Corethromyces bicolor differs most obviously from C. spectabilis Thaxt. in its shortened cell VI and compact, broad perithecium, but both species bear simple antheridia, have a darkened cell I, and possess four outer wall cells in each of the four vertical rows (Figs. 1i–k, 6a, b ). The relative sizes of cells I and II in both species are also similar. Mimeomyces decipiens, the type of the genus, bears distinctive compound antheridia (Figs. 5, 6c, d, e ) while C. bicolor does not (Fig. 1h, i, j ). Although the relative sizes and shape of receptacle cells I and II are similar in C. bicolor and M. decipiens the former differs most obviously in the darkened cell I and in one of the forms, the development of apical winglike lobes (Fig. 1h, i, j, k ). This latter character also serves to distinguish C. bicolor from other species of Corethromyces, Sphaleromyces, and Mimeomyces including M. andinus (Speg.) Thaxt., M. brachydiri (Thaxt.) Thaxt., and M. deplanatus (Thaxt.) II Tav. (Tavares 1985 ) (Fig. 6f ). Comparison of C. bicolor with the taxa remaining in the genus Sphaleromyces, in particular S. lathrobii Thaxt. (Fig. 6h, i ), reveals a number of important differences, including the precise arrangement of receptacular cells and the nature of the antheridial appendage. Another taxonomically informative character separating C. bicolor from any of the species in both Mimeomyces and Sphaleromyces is the number of outer wall cell tiers in the perithecium. In both Mimeomyces (Fig. 6d, f ) and Sphaleromyces (Fig. 6h ) there are five outer wall cell tiers. In C. bicolor, on the other hand, this study shows there to be only four tiers (Figs. 1k, 3 ).

View larger version (71K): [in this window] [in a new window]    FIG. 6. Other taxa to which C. bicolor has been allied. a) Mature thallus of C. spectabilis (AW-668A) showing tall cell I, flattened cell II, arrangement of perithecial stalk (VI, VII) and basal cells (m, n'), and the four tiers of outer wall cells (w1–w4) characteristic of the many species in the genus Corethromyces. b) Branched appendages of C. spectabilis with simple, seriate, free antheridia (an). c) Immature thallus of Mimeomyces decipiens (FH 2091) with developing perithecium, trichogyne (tr) and compound antheridia (an). d) Mature thallus of M. decipiens (FH 2088) with tall cell I, flattened cell II, compound antheridium (an), and perithecium with five tiers of outer wall cells (w1–w5). e) Enlargement of compound antheridium of M. decipiens (FH 2090). f) Mature thallus of M. deplanatus (FH 2307) with tall, darkened cell I, flattened cell II and perithecium with five tiers of outer wall cells. g) Immature perithecium of M. deplanatus (FH 2312) with undivided upper wall cell tier (o). h) Mature thallus of Sphaleromyces lathrobii (AW-822) with short cell I separated from cell II by an oblique septum. Note also the five tiers of perithecial outer wall cells (w1–w5). i) Immature thallus of S. lathrobii with obliquely arranged appendage cells and antheridia (an). Scale bars = 10 µm. FIG. 6a = Scale bar A. FIG. 6b = Scale bar B. FIGS. 6c–f, h = Scale bar C. FIG. 6i = Scale bar D. FIGS. 6e, g = Scale bar E

View larger version (22K): [in this window] [in a new window]    FIG. 7. The single most parsimonious tree based on partial sequences of SSU 18S rDNA. The tree is of 305 steps, with CI, RI, and RC of 0.6820, 0.4840, and 0.3301 respectively. Numbers on branches are bootstrap values from 1000 replicates of an heuristic search. The typical morphology of antheridia representative of the sub-families Ceratomycetoideae, Laboulbenioideae, and Peyritschielloideae have been mapped on the tree. Within the Laboulbenioideae four simple endogenous antheridial types are illustrated. Corethromyces bicolor is placed within the Laboulbenioideae, sub-tribe Stigmatomycetinae (bold lines)

	DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

Although based on a short partial sequence (525 bp) the molecular data also support placement of C. bicolor within the sub-tribe Stigmatomycetinae, the closest relationship being with an unidentified species of Corethromyces, rather than with Rickia (a member of sub-family Peyritschielloideae in which Mimeomyces is currently placed). Taken in combination, molecular, developmental and morphological data give strong support for Thaxter's inceptive placement of this fungus in Corethromyces. We hereby re-instate C. bicolor as a valid name and list Mimeomyces bicolor as a new synonym. Detailed morphological descriptions, host relationships, and geographical distribution of the two types of thalli observed are currently under investigation. Future studies on the classification of species and genera of Laboulbeniales should aim to combine morphology, development, and molecular datasets now that a reliable DNA extraction protocol and PCR amplification procedure are available (Weir and Blackwell 2001 ).

	TAXONOMY

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 

Corethromyces bicolor Thaxt., Proc Amer Acad Arts Sci 54: 220.

= Mimeomyces bicolor (Thaxt.) II Tav., 1985 p. 256, syn. nov.

	ACKNOWLEDGMENTS

 
The authors gratefully acknowledge funding for this research provided by the National Science Foundation Biotic Surveys and Inventories Program (Award #DEB 9972083 to A Weir, CE Carlton, and RAB Leschen) and Systematics Program (Award #DEB 9615520 to Meredith Blackwell). Permits to enable collecting in New Zealand were facilitated by Chris Green (Department of Conservation, Auckland, New Zealand) to whom we are also grateful. Chris Carlton (Louisiana State University, Baton Rouge, Louisiana), Rich Leschen, Elena Hilario, Grace Hall, and Robert Hoare (Manaaki Whenua Landcare Research, Auckland, New Zealand) freely made available their collections of New Zealand beetles and provided much needed logistical support. We are also indebted to Dr. Rich Leschen for identification of the hosts, to Dr. FA Rainey (Department of Biological Sciences, Louisiana State University) for assistance with DNA sequencing, to Dr. DH Pfister for loan of Thaxter slides from the Farlow Herbarium, Harvard University, to Dr. BM Spooner for loan of Thaxter slides from the Mycology Collections, Royal Botanic Gardens, Kew, to Dr. P Perkins for the loan of Thaxter host insects from the Museum of Comparative Zoology, Harvard University, to Dr. S Anagnost (Faculty of Wood Products Engineering, SUNY-ESF) for production of scanning electron micrographs, and to Dr. RK Benjamin (Rancho Santa Ana Botanic Garden, Claremont, CA) for helpful comments on an earlier draft.

	FOOTNOTES

 
¹ Corresponding author, aweir{at}syr.edu

Accepted for publication November 13, 2001.

	LITERATURE CITED

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMY LITERATURE CITED

 
Benjamin RK., 1971 Introduction and supplement to Roland Thaxter's contribution towards a monograph of the Laboulbeniaceae Bibliotheca Mycol 30:1-155

Benjamin RK., 1986 Laboulbeniales on semiaquatic Hemiptera. V. Triceromyces: with a description of monoecious-dioecious dimorphism in the genus Aliso 11:245-278

Felsenstein J., 1985 Confidence limits on phylogenies: an approach using the bootstrap Evol 39:783-791

Hawksworth DL, Kirk PM, Sutton BC, Pegler DM., 1995 Ainsworth & Bisby's Dictionary of the fungi. 8th ed Egham, UK: CAB International. 616 p

Swofford DL., 1999 PAUP: phylogenetic analysis using parsimony Version 4.059b

Tavares II., 1985 Laboulbeniales (Fungi, Ascomycetes) Mycol Mem 9:1-627

Thaxter R., 1892 Further additions to the North American species of Laboulbeniaceae Proc Amer Acad Arts Sci 27:29-45

Thaxter R., 1894 New genera and species of Laboulbeniaceae, with a synopsis of the known species Proc Amer Acad Arts Sci 29:92-111

Thaxter R., 1896 Contribution towards a monograph of the Laboulbeniaceae Mem Amer Acad Arts Sci 12:187-429

Thaxter R., 1901 Preliminary diagnoses of new species of Laboulbeniaceae. —IV Proc Amer Acad Arts Sci 37:19-45

Thaxter R., 1908 Contribution toward a monograph of the Laboulbeniaceae. Part II Mem Amer Acad Arts Sci 13:217-469

Thaxter R., 1912 New or critical Laboulbeniales from the Argentine Proc Amer Acad Arts Sci 48:153-223

Thaxter R., 1918 New Laboulbeniales from Chile and New Zealand Proc Amer Acad Arts Sci 54:205-232

Thaxter R., 1924 Contribution towards a monograph of the Laboulbeniaceae. Part III Mem Amer Acad Arts Sci 14:309-426

Thaxter R., 1926 Contribution towards a monograph of the Laboulbeniaceae. Part IV Mem Amer Acad Arts Sci 15:427-580

Thaxter R., 1931 Contribution towards a monograph of the Laboulbeniaceae. Part V Mem Amer Acad Arts Sci 16:1-435

Weir A, Blackwell M., 2001 Extraction and PCR amplification of DNA from minute ectoparasitic fungi Mycologia 93:802-806

Weir A, Hammond PM., 1997 Laboulbeniales on beetles: host utilization patterns and species richness of the parasites Biodiv Cons 6:701-719

White TJ, Bruns T, Lee S, Taylor JW., 1990 Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics In: Innis MA, Gelfand DH, Sninsky JJ, White TJ, eds. PCR protocols: a guide to methods and applications. New York: Academic Press. p 315–322

This Article Abstract Full Text (PDF) Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Weir, A. Articles by Hughes, M. Search for Related Content PubMed Articles by Weir, A. Articles by Hughes, M. Agricola Articles by Weir, A. Articles by Hughes, M.