aschersonia sp

18
A taxonomic revision of the insect biocontrol fungus Aschersonia aleyrodis, its allies with white stromata and their Hypocrella sexual states Miao LIU*, Priscila CHAVERRI, Kathie T. HODGE Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA article info Article history: Received 4 August 2005 Received in revised form 12 January 2006 Accepted 24 January 2006 Corresponding Editor: Richard A. Humber Keywords: Ascomycota Clavicipitaceae Molecular systematics Morphology Phylogeny abstract A revision of a monophyletic group of Hypocrella species and their Aschersonia anamorphs with white effuse stromata is presented. In addition to taxon descriptions, distributions, and nomenclature, a synoptic key and a molecular phylogenetic analysis are also provided. A new holomorph, Hypocrella rhombispora sp. nov., is described. This study presents a revisionary treatment of Aschersonia aleyrodis (teleomorph: Hypocrella libera) and its allies. These fungi parasitize whiteflies and are promising candidates for whitefly biological control. Four species of Aschersonia and their Hypocrella teleomorphs are treated in detail: Aschersonia aleyrodis/Hypocrella libera; A. andropogonis/H. andropogonis, A. placenta/H. raciborskii, and A. sp./H. rhombispora sp. nov. A synoptic key including these and six other morphologically similar species is presented to facilitate identification in the field and laboratory. Phylogenetic analyses of partial DNA sequences from three genes (LSU, mtSSU, and RPB2) suggest that Aschersonia species with effuse white stromata form a monophyletic group of whitefly pathogens. Phylogenetically informative characters in the group include the colour and shape of the stromata, the arrangement of tubercles con- taining perithecia, the arrangement of conidial masses on the stromata, and the shape of conidia and part spores. ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. Introduction Aschersonia aleyrodis (teleomorph: Hypocrella libera, Clavicipita- ceae, Hypocreales) was among the first fungi used in the biocon- trol of insect pests in North America. Its successful use in Florida citrus groves dates from the early 1900s, when citrus branches with A. aleyrodis were introduced into citrus groves to seed epizootics in the whitefly population (Berger 1921; Fawcett 1936). With the increase in chemical pesticide use be- ginning in the 1940s and 1950s, the demand for biocontrols diminished. Aschersonia species can still be found in whitefly populations in abandoned groves and backyard trees that are not managed with pesticides, where we have collected some specimens. Interest in using these fungi for the control of pests resumed in 1960s. In Bulgaria, China, Japan and the USSR (Evans & Hywel-Jones 1990), A. aleyrodis has been used against the greenhouse whitefly. The fungus has been devel- oped commercially by Koppert Biological Systems in Holland as a biopesticide suitable for application in greenhouses (Evans & Hywel-Jones 1990). Successful examples were also * Corresponding author. Current address: 201F Plant Science Bldg., University of Kentucky, Lexington, KY 40546 USA. E-mail address: [email protected]. available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/mycres mycological research 110 (2006) 537 – 554 0953-7562/$ – see front matter ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.mycres.2006.01.013

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Page 1: Aschersonia sp

ava i lab le at www.sc iencedi rec t . com

journa l homepage : www.e l sev i er . com/ loca te /mycres

m y c o l o g i c a l r e s e a r c h 1 1 0 ( 2 0 0 6 ) 537 – 554

A taxonomic revision of the insectbiocontrol fungus Aschersonia aleyrodis, its allieswith white stromata and their Hypocrella sexual states

Miao LIU*, Priscila CHAVERRI, Kathie T. HODGE

Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA

a r t i c l e i n f o

Article history:

Received 4 August 2005

Received in revised form

12 January 2006

Accepted 24 January 2006

Corresponding Editor:

Richard A. Humber

Keywords:

Ascomycota

Clavicipitaceae

Molecular systematics

Morphology

Phylogeny

a b s t r a c t

A revision of a monophyletic group of Hypocrella species and their Aschersonia anamorphs

with white effuse stromata is presented. In addition to taxon descriptions, distributions,

and nomenclature, a synoptic key and a molecular phylogenetic analysis are also provided.

A new holomorph, Hypocrella rhombispora sp. nov., is described.

This study presents a revisionary treatment of Aschersonia aleyrodis (teleomorph: Hypocrella

libera) and its allies. These fungi parasitize whiteflies and are promising candidates for

whitefly biological control. Four species of Aschersonia and their Hypocrella teleomorphs

are treated in detail: Aschersonia aleyrodis/Hypocrella libera; A. andropogonis/H. andropogonis,

A. placenta/H. raciborskii, and A. sp./H. rhombispora sp. nov. A synoptic key including these

and six other morphologically similar species is presented to facilitate identification in

the field and laboratory. Phylogenetic analyses of partial DNA sequences from three genes

(LSU, mtSSU, and RPB2) suggest that Aschersonia species with effuse white stromata form

a monophyletic group of whitefly pathogens. Phylogenetically informative characters in

the group include the colour and shape of the stromata, the arrangement of tubercles con-

taining perithecia, the arrangement of conidial masses on the stromata, and the shape of

conidia and part spores.

ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Introduction

Aschersonia aleyrodis (teleomorph: Hypocrella libera, Clavicipita-

ceae, Hypocreales) was among the first fungi used in the biocon-

trol of insect pests in North America. Its successful use in

Florida citrus groves dates from the early 1900s, when citrus

branches with A. aleyrodis were introduced into citrus groves

to seed epizootics in the whitefly population (Berger 1921;

Fawcett 1936). With the increase in chemical pesticide use be-

ginning in the 1940s and 1950s, the demand for biocontrols

diminished. Aschersonia species can still be found in whitefly

populations in abandoned groves and backyard trees that

are not managed with pesticides, where we have collected

some specimens. Interest in using these fungi for the control

of pests resumed in 1960s. In Bulgaria, China, Japan and the

USSR (Evans & Hywel-Jones 1990), A. aleyrodis has been used

against the greenhouse whitefly. The fungus has been devel-

oped commercially by Koppert Biological Systems in Holland

as a biopesticide suitable for application in greenhouses

(Evans & Hywel-Jones 1990). Successful examples were also

* Corresponding author. Current address: 201F Plant Science Bldg., University of Kentucky, Lexington, KY 40546 USA.E-mail address: [email protected].

0953-7562/$ – see front matter ª 2006 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.doi:10.1016/j.mycres.2006.01.013

Page 2: Aschersonia sp

538 M. Liu et al.

seen in Azerbaijan and Jamaica to control guava whitefly and

citrus whitefly, respectively (Borner 1956; McCoy, Samson &

Boucias 1988). Recent research has revealed that A. aleyrodis

has the virtues of high tolerance in low relative humidity

(Fransen 1987), long persistence on leaf surfaces (Meekes

et al. 2000), and compatibility with insect parasitoids (Fransen

& van-Lenteren 1993) in the control of whitefly pests.

However, some hurdles remain: Aschersonia species are

slow-growing in culture, and not all host life stages may be

attacked (Ramakers & Samson 1984). Recent studies on spore

production, germination, and pathogenicity have provided

a better understanding of the biology of A. aleyrodis in order

to further develop this promising biocontrol agent (Meekes

et al. 2002).

Despite early successes with A. aleyrodis, few other Ascher-

sonia species have been investigated for biological control po-

tential. Factors confronting researchers interested in

exploiting other species of the genus include: few species of

Aschersonia were available from culture collections before

our work, and had often been only tentatively identified; and

identification of newly collected cultures and specimens has

been difficult due to the scattered and out-dated literature

on the group (Evans & Hywel-Jones 1990). The primary re-

source available for identification has been Petch’s (1921) revi-

sion that needs to be updated in terms of number of species

and terminology.

Aschersonia species are found predominately in tropical

and subtropical habitats and infect either whiteflies or scale

insects, presumably by the germination and direct penetra-

tion of conidia adhering to the host cuticle (Meekes et al.

2002). We focus on a group of whitefly-pathogenic species

characterized by their effuse white stromata and brightly col-

oured conidial masses. Because of their gross similarity and

inadequate characterization in the literature, they are chal-

lenging to identify correctly, and we suspect that some re-

cords of A. aleyrodis represent misidentifications (Liu et al.

2001; Shu 1996; Sutton 1980; Tzean et al. 1997). For example,

the orange-spored species A. placenta (teleomorph H. racibor-

skii) differs from A. aleyrodis mainly in the former’s paleotrop-

ical distribution. We demonstrate here that A. goldiana is

merely a yellow-spored form of A. aleyrodis, as suggested by

Mains (1959a,b). Literature records of A. goldiana include mis-

identifications of other yellow-spored species such as

A. andropogonis, A. incrassata, or Aschersonia anamorph of Hypo-

crella rhombispora.

The ten species included in this study are all congeneric

with the type species Hypocrella discoidea (teleomorph) or

Aschersonia taitensis (anamorph). We revise and refine spe-

cies concepts for this group of Hypocrella/Aschersonia species

based on morphological examination of types and newly

collected specimens and cultures. We apply phylogenetic

analysis of DNA sequence data to evaluate whether mor-

phological species are phylogenetically discrete, and use

the analysis to discuss insights about relationships and

character evolution in the group. A synoptic key is pre-

sented to facilitate the field and laboratory identification of

species. We hope that the information presented here and

the isolates collected during our investigation will spur fur-

ther investigation into the biocontrol potential of these

fungi.

Materials and methods

Specimens and cultures

Species with white stromata include Aschersonia aleyrodis

(Hypocrella libera), A. placenta (H. raciborskii), A. andropogonis

(H. andropogonis), the Aschersonia anamorph of H. rhombispora,

and A. incrassata (H. zhongdongii) (Liu & Hodge 2005). Reference

species outside this apparently monophyletic group include

A. basicystis (H. phyllogena), A. cubensis, A. insperata, A. turbinata

and A. viridans. Fungal material was obtained in diverse forms:

fresh specimens from the field, isolates on artificial media, and

dried herbarium specimens. Fresh specimens were collected

from Bolivia, Cameron, China, Costa Rica, Florida (USA),

Ghana, Honduras, Mexico, Panama, and Puerto Rico (Table 1).

For most field collections, specimens were deposited in CUP

(Plant Pathology Herbarium, Cornell University, Ithaca). A por-

tion of each specimen from Costa Rica was deposited in INB

(Mycological Herbarium, National Biodiversity Institute, Santo

Domingo, Heredia, Costa Rica), and an isotype of H. rhombispora

was deposited in UPR (Herbarium, Botanic Garden, University

of Puerto Rico). Fungal cultures were made on potato-dextrose

agar (PDA; Difco, Albany, NY, USA) medium following the pro-

cedure described in Liu and Hodge (2005) and deposited in

ARSEF (ARS Collections of Entomopathogenic Fungi, Ithaca,

New York). Additional cultures were obtained from ARSEF,

BCC (BIOTEC Culture Collection, Bangkok) and CBS (Centraal-

bureau voor Schimmelcultures, Utrecht). Dried herbarium

specimens including types were borrowed from B (Herbarium,

Botanischer Garten und Botanisches Museum Berlin-Dahlem),

BPI (US National Fungus Collections, Beltsville, MD), CUP, FH

(Farlow Reference Library and Herbarium of Cryptogamic Bot-

any, University of Havard), HMAS (Mycological Herbarium In-

stitute of Microbiology, Beijing), K (Royal Botanic Gardens,

Kew), KRA (Herbarium, Institute of Botany, Krakow), MICH

(Herbarium, University of Michigan, Ann Arbor), PAD (Erbario

Patavinum, Centro Musei Scientifici, Padova), and S (Herbar-

ium, Botany Departments, Stockholm.)

Morphological examination

Microscopic characters were examined using optical micro-

scopes. For microscopic study, specimens were mounted in

85 % lactic acid–cotton blue. Digital photomicrographs were

taken with a SPOT RT camera (Diagnostic Instruments, Ster-

ling Heights, MI). Colours of the specimen and cultures were

recorded according to Kornerup and Wanscher (1967). Charac-

teristics of in vitro growth were recorded from cultures on PDA

at 23 �C.

DNA extraction, PCR and sequencing

DNA was extracted from the cultures following the procedure

of Liu et al. (2005). Regions of three genes were amplified by

PCR: nuclear LSU rDNA by primers LR0R and LR5 (Vilgalys &

Hester 1990), mtSSU rDNA by MTS1f and MTS3r (Liu & Hodge

2005), RNA polymerase unit II (RPB2) by RPB2-7f and RPB2-

11ar (Liu et al. 1999). Amplification conditions and sequencing

approaches were described by Liu and Hodge (2005).

Page 3: Aschersonia sp

Aschersonia aleyrodis and its allies 539

Table 1 – Fungal isolates, origins and GenBank accession numbers

Species specimen Isolate Origin GenBank accession no.

LSU mtSSU RPB2

- ARSEF992 Japan AY518368 DQ070136 DQ070203

Hypocrella raciborskii - ARSEF4209 MalDQ070sia DQ070074 DQ070141 DQ069953

Aschersonia placenta - ARSEF2154 Indonesia DQ070070 - DQ069951

- CBS34984 Japan DQ070135 DQ070200 DQ069958

- AFR28 Ghana DQ070113 DQ070180 DQ069965

CUP67562 AFR114 Cameron DQ070119 DQ070185 DQ069964

CUP67280 ARSEF7508 Costa Rica AY932752 AY932781 AY932766

CUP67303 ARSEF7512 Costa Rica AY932761 AY932791 AY932776

CUP67310 CR11 Costa Rica DQ070080 DQ070146 DQ070209

CUP67341 CR19 Costa Rica DQ070085 DQ070151 DQ069943

CUP67342 CR20 Costa Rica DQ070086 DQ070152 DQ069941

CUP-PR-4421 ML175-1 Puerto Rico DQ0700103 DQ07070 DQ069944

CUP-PR-4421 ARSEF7393 Puerto Rico DQ0700104 DQ070171 DQ069945

CUP-PR-4421 ARSEF7394 Puerto Rico DQ0700105 DQ070172 DQ069946

CUP-PR-4421 ML175-4 Puerto Rico DQ0700106 DQ070173 DQ069947

CUP67565 ARSEF7642 Guyana - DQ070201 DQ069950

H. libera CUP67435 ARSEF7339 Florida - DQ070162 DQ069934

A. aleyrodis CUP67435 ARSEF7340 Florida DQ070096 DQ070163 DQ06935

CUP67435 ARSEF7343 Florida DQ070099 DQ070165 DQ069936

- ARSEF7641 Panama - DQ070202 DQ069940

- ARSEF7617 Costa Rica DQ070121 DQ070187 DQ069942

CUP67519 PC413-1 Honduras DQ070122 DQ070189 DQ069937

CUP67525 PC434 Mexico DQ070126 DQ070192 DQ069938

CUP67528 PC439 Mexico DQ070128 DQ070194 DQ069939

CUP67529 PC442 Mexico DQ070129 DQ070195 DQ070232

CUP67288 CR05 Costa Rica AY518370 AY932784 AY932769

CUP67313 CR12 Costa Rica AY932755 AY932785 AY932770

CUP67316 CR13 Costa Rica AY932756 AY932786 AY932771

H. zhongdongii CUP67322 CR15 Costa Rica AY932757 - -

A. incrassata CUP67350 ARSEF7513 Costa Rica AY932758 AY932787 AY932772

CUP-PR-4394 ML149 Puerto Rico AY932759 AY932788 AY932773

CUP-PR-4394 ARSEF7369 Puerto Rico AY932760 AY932789 AY932774

CUP-PR-4314 ARSEF7071 Puerto Rico DQ070133 DQ070199 -

- ARSEF3014 Mexico DQ070073 DQ070140 -

- ARSEF4424 Brazil DQ070075 DQ070142 DQ070204

- CR03 Costa Rica DQ070076 DQ070143 DQ070205

CUP67291 ARSEF7510 Costa Rica AY932754 AY932783 AY932768

CUP67307 CR09 Costa Rica DQ07078 DQ070144 DQ070207

CUP67309 CR10 Costa Rica DQ070079 DQ070145 DQ070208

CUP67343 CR21 Costa Rica DQ070087 DQ070153 DQ070213

CUP67345 CR22 Costa Rica DQ070088 DQ070154 DQ069972

H. andropogonis CUP67436 ARSEF7341 Florida DQ070097 - -

A. andropogonis CUP67436 ARSEF7342 Florida DQ070098 DQ070164 DQ070218

CUP-PR-4407 ARSEF7391 Puerto Rico DQ070102 DQ070169 DQ070221

CUP-PR-4438 ARSEF7396 Puerto Rico DQ070109 DQ070176 DQ070223

CUP-PR-4438 ARSEF7397 Puerto Rico DQ070108 DQ070175 DQ069973

CUP-PR-4438 ARSEF7398 Puerto Rico DQ070110 DQ070177 -

CUP67515 PC384 Costa Rica - DQ070188 DQ070227

CUP67521 PC418 Honduras DQ070123 - DQ070228

CUP67523 PC431 Mexico DQ070124 DQ070190 DQ070229

CUP67524 PC432 Mexico DQ070125 DQ070191 DQ070230

CUP67526 PC436_1 Mexico DQ070127 DQ070193 DQ070231

CUP67531 PC451 Mexico DQ070130 DQ070196 DQ069974

CUP67532 PC452 Mexico DQ070131 DQ070197 DQ070233

CUP67533 PC455 Mexico DQ070132 DQ070198 DQ070234

CUP67556 AFR34A Ghana DQ070114 DQ070181 DQ069968

CUP67560 AFR68 Ghana DQ070115 - DQ069969

- AFR75 Cameroon DQ070116 DQ070182 DQ070226

CUP67561 AFR80 Cameroon DQ070117 DQ070183 -

CUP67563 ARSEF7639 Cameroon DQ070120 DQ070186 DQ069970

CUP67283 CR04 Costa Rica DQ070077 - DQ070206

H. phyllogena CUP67340 CR17 Costa Rica DQ070083 DQ070149 DQ070212

(continued on next page)

Page 4: Aschersonia sp

540 M. Liu et al.

Table 1 – (continued)

Species specimen Isolate Origin GenBank accession no.

LSU mtSSU RPB2

A. basicystis CUP67355 ARSEF7515 Costa Rica AY518373 AY932793 AY932778

CUP67296 ARSEF7511 Costa Rica AY518371 AY932790 AY932775

CUP CR32 Costa Rica DQ070094 DQ070160 DQ070217

H. rhombispora

and Aschersonia anamorph

CUP67369 CR34 Costa Rica DQ070095 DQ070161 DQ069977

CUP-PR-4406 ARSEF7390 Puerto Rico - DQ070168 DQ070220

ARSEF7395 Puerto Rico DQ070107 DQ070174 DQ070222

ARSEF7399 Puerto Rico DQ070111 DQ070178 DQ070224

ARSEF7400 Puerto Rico DQ070112 DQ070179 DQ070225

ARSEF1030 Columbia DQ070071 DQ070137 -

CUP67321 CR14 Costa Rica DQ070081 DQ070147 DQ070210

CUP67339 CR18 Costa Rica DQ070084 DQ070150 -

CUP67331 CR16 Costa Rica DQ070082 DQ070148 DQ070211

A. turbinata CUP67349 CR24 Costa Rica DQ070090 DQ070156 DQ070214

CUP67365 CR26 Costa Rica DQ070091 DQ070157 DQ070215

CUP67375 ARSEF7514 Costa Rica AY932762 AY932792 AY932777

CUP67375 CR29 Costa Rica DQ070093 DQ070159 DQ070216

CUP-PR-4388 ML142 Puerto Rico DQ070101 DQ070167 DQ070219

PR11 Puerto Rico DQ070134 - DQ070235

A. cubensis CUP67366 CR27 Costa Rica DQ070092 DQ070158 -

A. insperata ARSEF2396 Philippines AY518374 DQ070138 DQ069976

A. viridans CUP67282 ARSEF7509 Costa Rica AY932753 AY932782 AY932767

CUP67347 CR23 Costa Rica DQ070089 DQ070155 -

Genbank numbers in bold indicate the sequences generated in this study.

Phylogenetic analysis

DNA sequences of selected species (Table 1) were subjected to

phylogenetic analysis based on three gene regions LSU, mtSSU

and RPB2. The sequences were aligned using ClustalW

(Thompson et al. 1994) with default parameters, and adjusted

by eye in PAUP* 4.0b10 (Swofford 1998). Congruence among

the three data sets was evaluated by comparison of general

tree topologies and bootstrap supports for individual clades

(Mason-Gamer & Kellogg 1996). Based on the general congru-

ence, the three gene regions (LSU, mtSSU and RPB2) were

eventually combined in a single matrix; unavailable sequences

for individual taxa were scored as missing data. Excluding the

characters that could not be aligned without ambiguity

resulted in 2300 characters. To diminish the possible homo-

plasy caused by rapid evolution at the third codon position,

we down-weighted the third codon positions of the RPB2

data set as 1, while other characters (first and second codon

and non-coding regions) as 2. Parsimony analyses were con-

ducted using a heuristic search with TBR (tree bisection and

reconnection) branch-swapping and 100 replicates of random

sequence addition. Most gaps in LSU and mtSSU corresponded

with homopolymeric repeats. We consider them to be arte-

facts of sequencing, thus treat them as missing data (Sim-

mons et al. 2001). No gaps were observed in the RPB2 region.

Bootstrap (BS) analysis was based on 500 replicates of a full

heuristic search, each with 10 replicates of a random addition

sequence. The trees were rooted with the outgroup Hypomyces

aurantius (LSU AY932750, mtSSU AY932779, RPB2 AY932764),

Hypocrea strictipilosa (LSU AY932751, mtSSU AY932780, RPB2

AY932765), and Cordyceps militaris (LSU AB027379, mtSSU

AB027357, RPB2 AY932763). The distribution of key morpho-

logical characters was mapped onto the final tree topology

to investigate character evolution and to identify which char-

acters were phylogenetically informative.

Results

Aligned sequences from the LSU and RPB2 genes included 889

and 754 characters, respectively. For the mtSSU gene, a frag-

ment of 60 or so bases (nt 190–255) evolved extremely fast

and was excluded because it could not be unambiguously

aligned; other parts were readily aligned, resulting in 657 char-

acters. Phylogenetic analyses of the three gene regions

revealed no conflict in delimiting species. For relationships

among the clades (species), mtSSU gives no resolution, and

LSU and RPB2 conflict regarding the position of A. viridans.

Conflicts among the three genes were mainly found within

each clade (data not shown). Because there are no severe con-

flicts, the three data sets were combined into a single matrix

and subjected to phylogenetic analysis by a total evidence ap-

proach. Phylogenetic analysis revealed 359,900 equally parsi-

monious trees of length¼ 2534; CI¼ 0.573, RI¼ 0.896 and 456

phylogenetically informative characters (141, 72, 243 from

LSU, mtSSU and RPB2 respectively). The trees differed from

each other mainly in the relationships within the major

clades. A strict consensus tree is shown in Fig 1. Seven major

clades were well-supported in the BS analysis, each of which

was concordant with a morphologically defined species. The

relationships among these clades were clear in the strict con-

sensus but lack strong BS support. Morphological characters

Page 5: Aschersonia sp

Aschersonia aleyrodis and its allies 541

A. aleyrodis(H. libera)

A. incrassata(H. zhongdongii)

A. andropogonis(H. andropogonis)

A. basicystis(H. phyllogena)

H. rhombispora sp. nov.

A. turbinata(H. turbinata)

A. cubensis (H. epiphylla)A. insperataA. viridans(H. viridans)

100

Cordyceps militarisHypomyces aurantiusHypocrea stritipilosaARSEF 992CBS 34984ARSEF 4209AFR28CUP 67562ARSEF 7508ARSEF 7512CUP 67341CUP 67310CUP-PR-4421-1ARSEF 7393ARSEF 7394CUP-PR-4421-2ARSEF 7642CUP 67342ARSEF 7617ARSEF 7311ARSEF 7339ARSEF 7340ARSEF 7343CUP 67519CUP 67525CUP 67528CUP 67529ARSEF 7641ARSEF 3014ARSEF 4424CR03ARSEF 7510CUP 67307CUP 67343CUP 67345CUP 67309ARSEF 7341ARSEF 7342ARSEF 7391ARSEF 7396ARSEF 7397ARSEF 7398CUP 67556CUP 67560AFR75CUP 67561ARSEF 7639CUP 67515CUP 67521CUP 67523CUP 67524CUP 67526CUP 67531CUP 67532CUP 67533CUP 67288CUP 67313CUP 67316CUP 67322

ARSEF 7513CUP-PR-4394CUP-PR-7369 ARSEF 7071CUP 67283CUP 67340ARSEF 7515ARSEF 7511CR32CUP 67369ARSEF 7390ARSEF 7395ARSEF 7399ARSEF 7400ARSEF 1030ARSEF 7514CUP 67321CUP 67339CUP 67349 CUP 67331CUP 67365CUP 67375CUP-PR-4388PR11CUP 67366ARSEF 2396ARSEF 7509CUP 67347

100

100

99

100

96

97

99

D

A

B C

F

E

A. placenta(H. raciborskii)

Fig 1 – Strict consensus tree of 359,900 most parsimonious trees based on LSU rDNA, mtSSU DNA, and RNA polymerase unit

II (RPB2) gene. L [ 2534, CI [ 0.573, RI [ 0.896, 456 informative characters. Species that are morphologically well defined

appear as strongly supported clades. Phylogenetically informative characters are indicated as vertical hashmarks: (A) indi-

cates an effuse white anamorphic stroma; (B) confluent conidial masses, (C) cylindrical tubercles containing perithecia; (D)

discrete conidial masses; (E) formation of a rim around conidioma orifices; (F) conidia ventricose. In the A. aleyrodis and

A. placenta clade, taxa in bold produce yellowish orange conidial masses; others produce reddish orange conidial masses.

Page 6: Aschersonia sp

542 M. Liu et al.

were not included in the analysis; a select few were mapped

a posteriori onto the trees derived from DNA sequences.

Taxonomy

A synoptic key to treated species

Taxa treated in this work, as well as superficially similar spe-

cies, are included in the key below. Each species treated is ref-

erenced in the key by its number. All can be identified based

on either the anamorphic or teleomorphic stage. Two or

more species of Aschersonia may occur on different insects

on a single leaf.

1 A. australiensis

2 A. insperata

3 H. andropogonis/A. andropogonis

4 H. epiphylla/A. cubensis

5 H. libera/A. aleyrodis

6 H. phyllogena/A. basicystis

7 H. raciborskii/A. placenta

8 H. rhombispora/A. sp. (anamorph)

9 H. turbinata/A. turbinata

10 H. zhongdongii/A. incrassata

For each character there are two or more states; each charac-

ter state is followed by one or more numbers that represent

taxa. Underlined numbers indicate taxa exhibiting multiple

possible character states; taxon numbers not present in any

couplet indicate that the character is lacking or uncertain. Fur-

ther discussion of the use of synoptic keys can be found in

Korf (1972). All species are briefly discussed while detailed de-

scriptions of the species listed above in bold are included in

the taxonomic section following the key.

Teleomorph characters

Stromata

1.1 Colour

a Reddish orange.........................................................6

b Yellowish orange .................................................4, 9

c Reddish brown .........................................................4

d Yellowish white to white......................3, 5, 7, 8, 10

1.2 Shape

a Globose head markedly constricted at base.........6

b Pulvinate, base slightly constricted, slightly tubercu-

late ...............................................................3, 4, 8, 10

c Pulvinate with sloping sides, ovoid or globose tubercles

half-embedded .........................................................3

d Pulvinate with pronounced cylindrical or ovoid tuber-

cles .....................................................................5, 7, 9

1.3 Surface texture

a Tomentose ................................................................3

b Pruinose................................................................. ..5, 7

c Smooth (minutely tomentose or pruinose)

...................................................... ..3, 4, 5, 6, 7, 8, 9, 10

Perithecia

2.1 Position in stroma

a In gregarious but well-separated tubercles..3, 5, 7, 9

b In crowded, gregarious tubercles.........3, 4, 7, 8, 10

c Embedded in stroma, scattered .........................4, 6

2.2 Colour of ostioles

a Yellow to orange yellow........................3, 5, 7, 8, 10

b Reddish orange.........................................................5

c Brownish yellow.................................3, 5, 6, 7, 8, 10

d Red–brown ............................................................4, 6

2.3 Position of ostioles relative to the surrounding surface

a Slightly projecting....................................................6

b Not projecting.................................3, 4, 5, 7, 8, 9, 10

Part ascospores

3.1 Shape

a Cylindrical with rounded ends (Fig 2A)..3, 4, 5, 7, 10

b Fusoid (Fig 2B)...................................................4, 5, 7

c Ventricose with rounded or acute ends (Fig 2C)...6, 8

d Ovoid (Fig 2D) ...........................................................7

3.2 Width

a Less than 2 mm....................................3, 5, 6, 7, 8, 10

b 3–5 mm................................................................4, 7, 9

Anamorphic characters

Stromata

4.1 Colour

a Grayish brown..........................................................4

b Reddish orange...............................................2, 6, 10

c Light yellow ..........................................................4, 9

d Yellowish white to white..............1, 3, 5, 6, 7, 8, 10

4.2 Shape

a Pulvinate base with pezizoid projections .............9

Fig 2 – Shapes of part ascospores. (A) Cylindrical with

rounded ends. (B) Fusoid. (C) Ventricose with rounded ends.

(D) Ovoid.

Page 7: Aschersonia sp

Aschersonia aleyrodis and its allies 543

b Tuberculate.................................................2, 4, 9, 10

c Cylindrical.........................................................4, 5, 9

d Hemiglobose .....................................................4, 6, 8

e Scutate (a hemispheric central region abruptly attenu-

ating and extending to the edge) ....................7 3, 8

f Thick pulvinate, conical pulvinate.1, 3, 4, 5, 6, 7, 8, 10

g Thin pulvinate, sometimes with pronouncedly erect

tubercles............................................................2, 5, 7

h Thin pulvinate with embedded tubercles.............3

4.3 Hypothallus (a distinct thin layer of hyphae surround-

ing the base of the stroma and appressed to the plant

surface)

a Present.............................................1, 3, 5, 6, 7, 8, 10

b Absent .....................................1, 3, 4, 5, 6, 7, 8, 9, 10

Conidiomata

5.1 Approximate number of locules

a Fewer than ten .......................1, 3, 4, 5, 6, 7, 8, 9, 10

b More than ten.................................1, 3, 5, 7, 8, 9, 10

5.2 Shape of locules

a Simple depressions of surface without distinct

rims..............................................1, 3, 4, 5, 6, 7, 8, 10

b With distinct rims, like half-embedded bowls..3, 10

c Pezizoid .....................................................................9

5.3 Arrangement of ostioles on stroma

a Scattered .....................................1, 3, 4, 5, 7, 8, 9, 10

b Circular..............................................................5, 6, 7

5.4 Paraphyses in conidioma

a Present.....................................................1, 3, 5, 7, 10

b Absent .....................................1, 3, 4, 5, 6, 7, 8, 9, 10

Conidia

6.1 Colour of conidial masses

a Reddish brown .....................................................4, 9

b Reddish orange.....................................................5, 7

c Orange ...........................................................4, 5, 7, 9

d Deep yellow ..........................................................6, 8

e Pale yellow ..................................................3, 6, 8, 10

6.2 Shape of conidial masses on surface of stroma

a Discrete, erumpent or contained in conidio-

mata.................................................3, 4, 5, 7, 8, 9, 10

b Confluent, covering the centre of stroma.........5, 7

c Confluent, forming a ring around the stroma .....6

d Forming an erect cirrus.....................3, 4, 5, 7, 9, 10

6.3 Length of conidium

a Longer than 9 mm .......................3, 4, 5, 6, 7, 8, 9, 10

b Shorter than 9 mm ....................................................1

6.4 Width of conidium

a 1.6–3 mm...................................................1, 3, 5, 7, 10

b Wider than 3 mm ..........................................4, 6, 8, 9

6.5 Shape of conidium

a Fusoid (Fig 3A) ..........................................1, 2, 3, 5, 7

b Fusoid with ca 3–5 mm thickened wall at ends

(Fig 3B) .....................................................................10

c Ventricose (Fig 3C) ...............................................6, 8

d Ovoid with acute ends (Fig 3D) ..........................4, 9

e Ovoid (Hirsutella-like synanamorph) (Fig 3E) ........2

Cultural characters on PDA

7.1 Growth rate on PDA

a Relatively rapid, greater than 30 mm diam in three

weeks at 23 �C ..............................................4, 5, 7, 9

b Moderate, between 20 mm and 30 mm diam in three

weeks at 23 �C ..................................................2, 6, 8

c Slow, smaller than 20 mm diam in three

weeks at 23 �C ....................................................3, 10

7.2 Appearance and texture of the growing colony

a Spreading, minutely tomentose.................4, 5, 7, 9

b Compact, leathery..................................2, 3, 6, 8, 10

7.3 Colour of colonies

a Greyish white .......................................................3, 8

b White ...................................................................6, 10

c Yellowish white to yellow ..........................4, 5, 7, 9

d Orange yellow...........................................................2

7.4 Colour of conidial mass

a Pale yellow to yellow.....................................2, 3, 10

b Deep yellow ..........................................................6, 8

c Yellowish orange .................................................5, 7

d Reddish orange.............................................4, 5, 7, 9

e Brownish red ........................................................4, 9

7.5 Quantity of conidial mass

a Abundant ..........................................2, 4, 5, 6, 7, 8, 9

b Scanty..................................................................3, 10

7.6 Hirsutella-like synanamorph

a Present.......................................................................2

b Absent .........................................3, 4, 5, 6, 7, 8, 9, 10

1. Aschersonia australiensis Henn., Hedwigia42: 87 (1903).

Note: This species resembles A. placenta in its orange–red

conidial masses, but differs in having distinctively smaller

conidia (5–8 mm) (Petch 1921). It has been reported from

Fig 3 – Shapes of conidia. (A) Fusoid. (B) Fusoid with thick-

ened wall at ends. (C) Ventricose. (D) Ovoid with acute ends.

(E) Ovoid conidium of Hirsutella-like synanamorph.

Page 8: Aschersonia sp

544 M. Liu et al.

Australasia (Hennings 1903). No teleomorph is known, and the

species has not been well studied. Detailed descriptions were

provided by Petch (1921). A. australiensis is further discussed

under H. raciborskii.

2. Aschersonia insperata Rombach et al.,Mycologia 97: 251 (2005).(Fig 3E)

Note: The most distinctive character of this species is its pro-

duction of both Aschersonia and Hirsutella-like synanamorphs

in young cultures and specimens, which has not been found

in any other species in this genus. The reddish orange tuber-

culate stroma of this anamorphic species appears superficially

like the perithecial stroma of H. turbinata, but only asexual

spores are produced. A. insperata is known only from the

type collections in the Philippines, and the teleomorph re-

mains unknown. A detailed description of this species was

provided by Liu et al. (2005).

3. Hypocrella andropogonis Petch, Ann. Roy. Bot. Gard.Peradeniya 7: 247 (1921).

Typus: Trinidad: On leaves, R. Thaxter 18 (K(M) 120354-

holotypes).

Anamorph: Aschersonia andropogonis Henn., Hedwigia 39: 139

(1900).

Neotype: Puerto Rico: Mayaguez, beside Road 105, on ferns,

15 Dec. 2003, M. Liu & Z.D. Wang (CUP-PR 4407) neotypus hic

designatus).

Synonyms: Aschersonia parasitica Henn., Hedwigia 43: 149

(1904).

Aschersonia lecanioides Henn., Hedwigia 41:145 (1902).

Figs 4A–C, Fig 5

Teleomorphic stromata flattened pulvinate with subglo-

bose tubercles (Fig 4A), some tubercles fused together

(Fig 5A), but more often discrete, surface minutely tomentose,

white or orange–white (darkened in very old specimens), 1–

3 mm diam, 0.4–0.5 mm thick, edges of the stromata extend-

ing to form a hypothallus (Fig 4B, 5B). Perithecia develop singly

in the tubercles (Fig 5C), flask-shaped, 250–450 mm deep, 160–

300 mm diam at the widest point. Asci produced from basal

clusters, cylindrical, 138–180 mm long, 5–8 mm wide, caps 3–

3.5 mm thick (Fig 5D). Ascospores filiform, slight shorter than

the perithecia, septate, dividing into part spores that are cylin-

drical with rounded ends, 12–15� 1.5–2 mm (Fig 5E).

Teleomorph and anamorph may or may not be present in

the same stromata (Figs 4B 5A–B, F). Strictly asexual stromata

usually pulvinate (Figs 4C, 5B, F), white to pale yellow (4A3–

4A5), 1–4 mm diam, 0.5–1 mm thick. Hyphae of stromata

forming compact textura intricata, 3–6 mm wide with a thick-

ened wall, 1–2 mm wide, Conidiomata scattered in stromata,

1–6 per stroma, widely open, orifice circular, 0.1–0.6 mm

diam, rim of conidiomata sometimes distinctly elevated, con-

idioma resembles a half-immersed bowl (Fig 4C). Conidial mass

yellow (4A8), yellowish orange (4B7) to orange (5A8), usually

contained in conidioma (Figs 4C, 5F), but sometimes erumpent

or forming a column-like cirrus, never fused with conidial

masses from adjacent conidiomata. In section, the conidioma

is U- or V-shaped (Fig 5G). Conidioma with hymenium lining

inner surface; most conidiogenous cells arise from thick-

walled hyphae, unbranched, cylindrical, slightly narrower

near their truncate ends, unicellular, 7–16� 1–1.5 mm; some

are branched (Fig 5H). Conidia fusoid, apices more or less blunt,

8–14� 1.5–2 mm (Fig 5I), produced in copious slime. Paraphyses

present in some specimens, ranging from 60–160 mm long

(Fig 5H).

On PDA colony grows very slowly, reaching 15–25 mm diam

in five weeks at 23 �C. Stromatic colonies white to greyish

white, compact, forming a thick pulvinate structure, surface

minutely velvety, wrinkled (Fig 4A). Colonies both filamentous

hyphae and hyphal bodies, the latter usually 5–16� 3–7 mm

with a thickened wall (not over 1 mm thick). Conidial masses

usually not abundant, appear as tiny drops scattered on sur-

face or very thin streams along wrinkles in the colony. When

picked with a needle, the conidial masses appear as a solid

mass that is light yellow to yellow. Isolates are liable to lose

their ability to sporulate in serial subculture. Conidiogenous cells

10–17� 1.5–2 mm, conidia fusoid, apices acute, 8–12� 1.5–2 mm.

Paraphyses usually long and abundant, up to 190 mm long.

Known distribution: Bolivia, Cameroon, China, Costa Rica,

Ghana, Honduras, Mexico, Puerto Rico, Trinidad, USA.

Other specimens examined: Cameroon: Korup National For-

est, Oct. 2003, H.C. Evans & G. J. Samuels (AFR116¼ARSEF

7639¼CUP67563); Costa Rica: Heredia: OTS La Selva Biological

Station, Sendero Holdridge, 18 June 2002, M. Liu (CUP 067291);

Camino Cantarrana, 19 June 2002, M. Liu (CUP 067307); Beside

entrance to plantation, June 20, M. Liu (CUP 067343, 067345).

Ghana: Central Region, Jukua District, Kakum National Park,

N05 �210, W01 �230, elev. 280 m, Oct. 2003, H.C. Evans & G. J. Sam-

uels, AFR34¼CUP 67556, AFR68¼CUP 67560. Java: Buitenzorg,

Kulturgarten, on leaf of Mangifera indica, 1901, Zimmermann,

(S F22432-type of A. lecanioides). Mexico: Veracruz: Municipio

Emiliano Zapata, Plan Chico, N19 �26.7350, W96 �49.8650, elev.

900 m, 11 Dec. 2003, P. Chaverri, J. Hernandez, J. Garcia-Alvarado

PC431, (CUP 67523); behind Instituto Genetica Forestal Univer-

sidad (Veracruzana) building, 12 Dec. 2003, P. Chaverri &

J. Garcia-Alvarado (PC432¼CUP 67524); Catemaco, Ejido: Lopez

Mateo town, project ‘Cielo, Tierra Y Selva,’ trail to mountain,

200–300 m elev., 13 Dec. 2003, P. Chaverri, J. Garcia-Alvarado &

C. Mena-Jiles (PC436¼CUP 67526, PC452¼CUP 67532). Philip-

pines: Laguna: Mt. Maquiling, near Los Banos, Feb. (18)94,

C.F. Baker (FH 8); Paraguay. Cerro Coche: On leaves of Andropo-

gon sp., K. Fiebrig 779 (B 70 0005658: type of A. parasitica). Puerto

Rico: Guajataca, trail no.9, on ferns, M Liu & ZD Wang (CUP-PR

4438). USA: Florida: Micanopy, cross creek, Marjorie Kinnan

Rawling’s residence, on Citrus, 22 Aug. 2003, M. Liu & Z.D.

Wang (CUP 67436).

Notes: A. andropogonis is easily distinguished from A. aleyr-

odis when the conidiomata of the former have elevated edges,

but resembles a yellow-spored form of A. aleyrodis with thick

stromata in cases where the conidiomata are simply depres-

sions of the surface. A. andropogonis generally differs in pos-

sessing conidiomata with very wide openings, fewer

conidiomata (1–6), conidial masses that do not fuse with those

from adjacent conidiomata, and longer paraphyses; while A.

aleyrodis may possess many conidiomata (1–20), smaller and

sometimes radially elongated orifices, and confluent conidial

masses. The colony morphology on PDA reveals more obvious

differences: A. andropogonis produces small, slow growing,

Page 9: Aschersonia sp

Fig 4 – Cultural morphology on PDA and stromata of selected species. (A) Culture of Hyporella andropogonis/Aschersonia an-

dropogonis. Compact colonies bear pale yellow conidial masses in small discrete drops. (B) H. andropogonis (CUP-PR 4438): ovoid

tubercles are half-embedded in the white pulvinate stroma. (C) A. andropogonis (CUP-PR 4407): conidial masses are contained in

conidiomata, and the openings of the conidiomata have distinct rims. (D) Cultures of H. libera/A. aleyrodis: the colonies are

effuse, white, and fluffy, and bear abundant confluent conidial masses; colouration varies from orange to reddish orange. E H.

libera (MCA2335). Stromatal tubercles are cylindrical, gregarious, and crowded. F A. aleyrodis (CUP 067341) has flattened pul-

vinate stroma, and the conidiomata produce reddish orange conidial masses. G. Culture of H. raciborskii/A. placenta: colonies

are fluffy and spreading, conidial masses are abundant and confluent, and colouration varies from yellowish-orange to or-

ange. H. H. raciborskii (CUP-CH 002621) showing gregarious cylindrical tubercles in which perithecia are embedded. I. A. pla-

centa (CUP-CH 002620) with a flattened pulvinate stroma, and confluent yellowish orange conidial masses. J. Culture of

H. rhombispora showing the compact colony with abundant yellow to orange conidial masses in discrete small drops. K. H.

rhombispora (CUP 067548). A minutely tuberculate stroma with a slightly constricted base. L. Anamorph of H. rhombispora (CUP

067551). Scutate stroma with yellowish orange conidial masses contained in the conidiomata. Bar [ 500 mm.

Page 10: Aschersonia sp

546 M. Liu et al.

Fig 5 – Hypocrella andropogonis/Aschersonia andropogonis. (A) Tuberculate stroma of sexual state (K(M) 120354-holotype). (B)

Stroma with sexual (tubercles) and asexual state (holes). (C) Flask-shaped perithecium embedded in a tubercle. (D) Cylindrical

asci containing filiform ascospores. (E) Cylindrical part spores with rounded ends. (F) Anamorphic stroma with one coni-

dioma in the centre; conidial mass contained in conidioma. (G) Conidioma a simple depression forming a ‘U’ shape in sec-

tion. (H) Long paraphyses and conidiogenous cells. (I) Fusoid conidia. Bar [ 500 mm for Figs A–B, F; 100 mm for Figs C, G; and

10 mm for Figs D–E, H–I.

compact, and greyish white colonies with a minutely velvety

and often wrinkled surface, while the A. aleyrodis grows faster

and the white or yellowish white colonies are effuse and mi-

nutely fluffy.

A. lecanioides was considered by Petch (1921) to be a syn-

onym of A. placenta based on similar conidia and paraphy-

ses. We examined the type specimen and observed elevated

edges of conidioma and other characters consistent with

A. andropogonis. A. andropogonis has longer paraphyses

than A. placenta. The paraphyses of A. lecanioides measured

70–114 mm, longer than those in A. placenta (40–70 mm).

Hennings (1902) described the stromata as pale to yellow,

as in A. andropogonis. The sexual state lacks cylindrical

tubercles as in H. raciborskii, but forms subglobose tubercles

that are half or totally embedded in the flattened stromata,

as in H. andropogonis. We propose that A. lecanioides is con-

specific with A. andropogonis.

We conclude that specimens identified by Fawcett (1908)

from Florida as A. flavocitrina are A. andropogonis. Fawcett’s de-

termination was based mainly on the yellow colour of the

spore masses. Based on our type studies, A. flavocitrina has dis-

tinctive orange discoid stromata and can be easily distin-

guished from A. aleyrodis. Considering the characters of

colonies on PDA he described in the same paper, Fawcett’s

specimens, which we were unable to locate, were probably

A. andropogonis, which produces small and compact stromatal

colonies.

4. Hypocrella epiphylla Sacc., Syll. Fung. 11: 368 (1895).

Anamorph: Aschersonia cubensis Berk. & M. A. Curtis, J. Linn. Soc.

10:351 (1869).

Notes: H. epiphylla is common in the subtropical eastern US.

The stromata typically are squat, cylindrical, and more com-

pact and slightly darker in colour than those of the A. aleyrodis

group. The differences are sometimes subtle, and young stro-

mata can be confused with those of A. aleyrodis. However, the

conidia of this species are wider and shorter than those of A.

aleyrodis, a distinctive character that H. epiphylla shares with

its sister species, H. turbinata (Fig 1). The teleomorph is infre-

quently collected. For a detailed description, see Petch (1921).

5. Hypocrella libera Syd., Ann. Mycol. 14: 85 (1916).

Type: Bolivia: Cobija: Rio Acre, on coccids on fallen leaves, Jan.

1912, E. Ule 3413 (W. 00939-holotypes).

Synonym: Hypocrella nectrioides Petch, Ann. Roy. Bot. Gard.

Peradeniya 7:225 (1921).

Anamorph: Aschersonia aleyrodis Webber, Bull. USDA Div. Veg.

Phy. Path. 13:21 (1897)

Type: USA: Florida: Manatee County, on whitefly on citrus,

Dec. 1896, H. J. Webber (BPI 0389438–lectotypus hic designatus).

Synonyms: Aschersonia goldiana Sacc. & Ellis, in Saccardo,

Syll. Fung. 14: 990 (1899).

Aschersonia paraensis Henn., Hedwigia, 41: 17 (1902).

Page 11: Aschersonia sp

Aschersonia aleyrodis and its allies 547

(Figs 4D–F, 6)

Stroma white, yellowish to orange white (4A2–5A2), com-

posed of a few to numerous gregarious tubercles arising

from a pulvinate to hemispherical base (Fig 4E, 6A); sometimes

surrounded by a thin hypothallus 0.7–2.0 mm wide; surface of

tubercles and base pruinose due to loosely woven, thick-

walled hyphae that form stroma (Fig 6D). Tubercles strongly

projecting and aggregated, hemispherical, cylindrical or

slightly narrowing apically, 0.3–0.5 mm diam, 0.3–0.7 mm in

height; apices reddish orange (7A6) in fresh specimens, fading

to yellow when dry, in old specimens appearing amber

(brownish yellow 5C7). In most cases ostioles difficult to distin-

guish from surrounding glabrous tissue; in a few cases they

are visible, ca 0.1 mm diam. Perithecia fully embedded

(Fig 6B), one perithecium per tubercle, the shape of perithecia

in section nearly globose to ovoid, 300–400� 300–600 mm; stro-

matal tissue around perithecium textura intricata (Fig 6D). Asci

cylindrical, with a thick cap ca 5 mm long. Ascospores filiform,

slightly shorter than perithecia, septate, sometimes helically

twisted in ascus, disarticulating into oblong oval or cylindrical

spores, slightly tapering towards ends, with somewhat

rounded ends, 13–16� 2.5–3 mm (Fig 6C).

Separate from sexual stroma, anamorphic stroma thin pul-

vinate (Figs 4F, 6E–F), 1–2 mm diam, 0.1–0.3 mm thick, or scu-

tate 1–3 mm diam, 0.5–1 mm thick, white, minutely

tomentose; hypothallus usually present in pulvinate stromata,

0.3–1.0 mm in width, present or absent in scutate stromata;

centre of stromata usually covered with conidial masses red-

dish orange (7A6), orange (5A8–6A8), or light yellow (3A5–4A7),

thickened in centre. Conidiomata circularly arranged (Fig 4F) or

scattered (Fig 6F); 3–20 per stroma; shape of conidiomatal os-

tioles circular, radially elongated or irregular due to fusion of

adjacent ostioles; widely open, appearing as simple depres-

sions of stromatic surface without a differentiated rim; coni-

dioma shape in section globose (Fig 6G) or irregular. Conidial

masses exuded from conidiomata as a viscous fluid, usually

overflowing and confluent, sometimes forming a long erect

cirrus. Conidiogenous cells, phialidic, 10–20 1–1.5 mm, arise sin-

gly or in whorls of 2–5 from compact, thick-walled hyphal tis-

sues (Fig 6I), not branched, thin-walled, smooth, cylindrical,

slightly tapering, truncate at apices. Conidia fusiform (Fig 6K),

unicellular, hyaline, guttulate, ends acute but not prolonged,

(9.0–) 10–16 (–18)� 1.5–2.0 (–2.5) mm, produced in copious

slime. Paraphyses abundant in the hymenium, especially in

thick stromata, hyaline, not staining in cotton-blue, filiform,

50–90 (–113)� 1.0–1.5 mm (Fig 39).

Colonies (Fig 4D) on PDA growing relatively fast, 35 mm

diam in three weeks at 23 �C, filamentous hyphae, tomentose,

white to yellowish white (4A4–4A5), sometimes with a gray-

ish-yellow (4B4) peripheral circle. Conidial mass variable in col-

ouration (Fig 4D), light orange (5A4–5A5), deep orange (6A7) to

reddish orange (7A7), abundant, confluent. Most conidiogenous

cells, 10–19� 1.0–1.5 mm, arise mononematously and laterally

from thick-walled hyphae, or in a whorl of 2–6 from the end

Fig 6 – Hypocrella libera/Aschersonia aleyrodis. (A) H. libera (CUP 067303) stroma: cylindrical tubercles arise from hemispherical

base; surface pruinose. (B) Flask-shaped perithecium embedded in a tubercle; surrounding tissues are textura intricata. (C)

Asci with helically twisted ascospores, which disarticulate into oblong ovoid part spores. (D) Tissues of the stromatal surface

are textura intricata. (E) Stroma of A. aleyrodis (CUP-PR 4421), confined by hairs on the leaf. (F) Stroma of A. aleyrodis with

scattered conidiomata (BPI 0389440). (G) Globose conidioma with hymenium, conidia and paraphyses. (H) Paraphyses ex-

tending above the hymenium. (I) Conidiogenous cells from culture arising singly from hyphae or clustered apically on hy-

phae. (J) Branched conidiogenous cells extending above the hymenium. (K) Fusoid conidia. Bar [ 500 mm for Figs A, E–F;

100 mm for Figs B, G; 10 mm for Figs C–D, H–K.

Page 12: Aschersonia sp

548 M. Liu et al.

of thick-walled hyphae (Fig 6I); but conidiophores with multi-

ple branches also observed in culture, 35–65 mm, some phia-

lides elongated to the length of paraphyses (Fig 6J). Conidia

fusoid, 9–13� 1.5–2.0 mm, paraphyses not ordinarily observed

in all isolates, 40–123 mm when present.

Known distribution: Bolivia, British Honduras, Costa Rica,

Cuba, Dominican Republic, Jamaica, Panama, Puerto Rico, Tri-

nidad, Venezuela (Mains 1959a,b), and Florida, Mississippi,

and Texas in the United States.

Other specimens examined: Brazil: Para, auf lebenden Blat-

tern von Psidium pomiferum, May 1901, J. Huber 50 (S F22444,

as A. paranesis). Costa Rica: Heredia: OTS La Selva Biological

Station, laboratory area, 17 June 2002, M. Liu (culture

CR01¼CUP 067280); Camino Cantarrana, 19 June 2002, M. Liu

(CUP 067298, CUP 067303¼ARSEF 7512, culture CR11¼CUP

067310); plantation beside entrance RCC, 20 June 2002, M. Liu

(culture CR19¼CUP 067341, culture CR20¼CUP 067342);

Sendero Oriental 450 m, 20 June 2002, M. Liu (CUP 067325); suc-

cession plots, 20 Aug. 2003, P. Chaverri PC321¼ARSEF 7617.

Guyana: Kamarang: on line to old Ayanganna Airstrip, west

Pakaraima mountains, upper Potaro river, 20 km east of

Mount Ayangana, near confluence of Potaro and Alukyadong-

baru Creek, general area N5 �160, W59 �540, approximately

650 m elev., 8 Jan. 2004, C. Aime, MCA 2465¼ARSEF 7642. Mex-

ico: Veracruz: Catemaco, Ejido Lopez Mateo town, project

‘Cielo, Tierra Y Selva’, trail to mountain, 20–300 m elev., 13

Dec. 2003, P. Chaverri, J. Garia-Alvarado, C. Mena-Jiles,

PC434¼CUP 067525¼ARSEF 7706, PC439¼CUP 067528. Pan-

ama: Furtuna: Behind field station, 14 July 2002, J. F. Bischoff,

JB133 (¼ARSEF 7641). Puerto Rico: Guillarte: RD 388 trail, 16

Dec. 2003, M. Liu & Z. D. Wang (culture ML175-1, ML175-2,

ML175-3, ML175-4¼CUP-PR 4421¼ARSEF 7393, ARSEF 7394);

On Psidium guajaba, 1912, (FH 360 as A. goldiana). Trinidad:

Port of Spain, St. Ann’s Valley, on scale insect on Pentaclenthra

sp., R. Thaxter, K(M)120325 (H. nectrioides); Maraval Valley,

1912–1913, R Thaxter (FH); Anne’s valley, on leaves of Adiantum,

Feb. 1913, R. Thaxter, (FH, as A. goldiana). United States: Florida:

Manatee County, on whitefly on Citrus, Dec. 1896, H. J. Webber

(BPI US0389440); Mar. 1896, H. J. Webber (BPI 0389439); Mica-

nopy, Cross Creek, Majorie Kinnan Rowlings’ residence, on Cit-

rus, 22 Aug. 2003, M. Liu & Z.D. Wang (CUP 067435¼ARSEF

7339, ARSEF 7340, ARSEF 7343, ARSEF 7344); Lake Alfred, on cit-

rus leaves, 9 Jan. 1980, R.S. Soper (living culture ARSEF 430); on

scale insects on citrus leaves, F.A. Wolf, (F.H. gift from

F.A. Wolf); Inverness, 14 Feb. 1923, E.W. Berger 34 (FH 6298,

as A. goldiana); Gainesville, 1923, E.W. Berger (FH 6301 as

A. goldiana).

Notes: A. aleyrodis is distinct in having a neotropical and

subtropical distribution, orange (or sometimes yellow), nar-

row fusoid conidia, and a tuberculate teleomorph. Histori-

cally, there has been taxonomic confusion regarding the

relationship between A. aleyrodis, commonly called the ‘red

fungus,’ and the ‘yellow fungus’ A. goldiana (Fawcett 1908).

Petch (1921) and Mains (1959a, b) observed that the two spe-

cies were only distinguished by the colour of the conidial

mass, that of the former being red to reddish orange, and

the latter yellow to orange. We mapped conidial mass colour

onto the phylogenetic tree shown in Fig 1 and found that it

is not an informative character within the A. aleyrodis clade.

We also examined the type of A. goldiana. Based on the shape

of the stroma, the confluence of the conidial masses, and the

shape of conidia, we conclude that A. goldiana is a synonym of

A. aleyrodis.

The connection between H. libera and A. aleyrodis was first

inferred by Petch (1925) based on two specimens from Pan-

ama. Mains (1959a) cast doubt on the connection due to the in-

consistency of the host: H. libera was described on coccids

(Sydow & Sydow 1916), whereas A. aleyrodis was described

on Aleyrodes (Webber 1897). However, our examination of the

type specimens convinced us that H. libera is indeed the tele-

omorph of A. aleyrodis, and we feel the host might have been

misidentified by Sydow & Sydow (1916): the black oval-shaped

insect may be a whitefly nymph. Our phylogenetic analysis

reaffirms the connection. Isolates from ascospores of fresh

H. libera collections (CR08 and CR11) grouped together with

those from A. aleyrodis conidia (Fig 1). An unidentified species

that is the source of GenBank sequence no. U47832 was re-

cently identified as H. nectrioides based on morphological ex-

amination of the voucher specimen (Bath et al. 2005). We

examined the type specimen of H. nectrioides, the general

morphology of the stromata of which resembles H. libera. No

asci were found, but, based partly on Petch’s description

(Petch 1925), we consider this taxon to be a synonym of

H. libera.

H. sloaneae is similar to H. libera. The subtle differences in-

clude: tubercles in H. sloaneae are crowded and ovoid, whereas

those of H. libera are separated and cylindrical; and the stro-

matal surface of the former is more coarse, whereas the latter

is more glabrous. We did not observe the anamorph in the

type from FH (Guadeloupe: Bois des Bains-Jaunes, 1904); how-

ever, Petch (1921) recorded anamorph characters from the

type of H. amazonica (Peru: on Sterculiaceae, Iquitos, July

1902, E. Ule, Herb. Brasil. no. 3198), which he considered to

be conspecific with H. sloaneae. According to Petch (1921), the

unnamed Aschersonia anamorph of this fungus produces

a red–brown spore mass, and thus differs from that of A. aleyr-

odis. As already mentioned, colouration of conidial mass is

not a constant character in A. aleyrodis/H. libera, which pro-

duces both yellowish orange and reddish orange conidial

masses.

6. Hypocrella phyllogena Petch, Ann. Roy. Bot. Gard.Peradeniya 7: 228 (1921).

Anamorph: Aschersonia basicystis Berk. & M.A. Curtis, Jour. Linn.

Soc. Bot. 10: 352 (1869).

Notes: This species has a distinctive sexual stroma, which is

reddish orange and composed of a globose head that is mark-

edly constricted at the base. Dull yellow conidial masses are

produced at the narrowest part of the constriction, forming

a ring around the ‘head.’ This species is variable and appears

to be a complex of several species. In the early stages of devel-

opment before the perithecia are formed, this species resem-

bles anamorph stage of H. rhombispora. Both have white

pulvinate stromata, yellow conidial masses contained in the

conidiomata, and ventricose conidia. However, the conidio-

mata of anamorph stage of H. basicystis are circularly arranged

around the base of stroma, while conidiomata of A. rhombis-

pora are scattered on the stroma surface. This species is fur-

ther discussed under H. rhombispora.

Page 13: Aschersonia sp

Aschersonia aleyrodis and its allies 549

7. Hypocrella raciborskii Zimm., Centralblatt f. Bakt.7: 875 (1901).

Type: Zimmermann (Centralblatt f. Bakt., 7: 875 fig 4, 1901 –

lectotypus hic designatus. China: Guangdong: Dinghushan, 10

Aug. 2004, B. Huang DHS040810-11 (CUP CH 002621 – epitypus

hic designatus). Ex-epitype living culture¼ARSEF 7609¼CHN4).

Synonyms: Hypocrella warneckiana Henn., Engler’s Bot. Jahrb. 38:

113 (1905).

Barya salaccensis Racib., Bull. Akad. Sci. Cracovie: 909 (1906).

Anamorph: Aschersonia placenta Berk., J. Linn. Soc. Bot. 14: 89

(1875).

Type: Sri Lanka: on leaves of Loranthus sp., 1879, G. H. K.

Thwaites (K(M)81383-holotype).

Synonyms: Aschersonia novoguineensis Henn., Engler’s Bot.

Jahrb. 25: 509 (1898).

Aschersonia javanica Penz. & Sacc., Malpighia 20: 236 (1901).

Aschersonia tamurai Henn., Engler’s Bot. Jahrb. 31: 741 (1902).

(Figs 4G–I, Fig 7)

Stromata white to yellowish white, 1–2 mm diam; tubercu-

late processes developing from a thin pulvinate base (Figs 4H,

7A); tubercles usually isolated from one another, rarely

densely aggregated, occurring at margins when conidiomata

are present in centre. Tubercles cylindrical, ovoid or subglo-

bose, 0.3–0.5 mm diam, up to 0.5 mm in height. Perithecia em-

bedded singly in tubercles (Fig 7B), flask-shaped or ovoid, 300–

420 mm deep, 200–300 mm wide with walls 20–32 mm thick. Os-

tioles yellow (3A6–4A6) to orange–yellow, darkening to deep or-

ange in old specimens; readily visible. Stromatal tissue textura

intricata around perithecium (Fig 7E). Asci cylindrical (Fig 7C),

140–220� 5–7 mm with 5–6 mm thick caps. Ascospores filiform,

slightly shorter than perithecia, septate, dividing into part

Fig 7 – Hypocrella raciborskii/Aschersonia placenta. (A) Sexual stroma. (B) Flask-shaped perithecium embedded in a tubercle;

ostiole is not erumpent. (C) Asci. (D) Ovoid part spores. (E) Tissues of stromata, more compact near the perithecial wall

(top). (F) Asexual stroma with confluent conidial masses (CUP-CH 002620). (G) Asexual stroma of the type specimen,

(K(M)81383), in which conidiomata are circularly arranged. (H) Hymenium showing paraphyses and conidiogenous cells.

(I) Conidiogenous cells arising singly from thick-walled hyphae (in type specimen). (J) Conidiogenous cells showing

branching patterns in culture. (K) Long conidiogenous cells resembling paraphyses. (L) Fusoid conidia containing guttules.

Bar [ 500 mm for Figs A, F–G; 100 mm for Fig B; and 10 mm for C–E, H–L.

Page 14: Aschersonia sp

550 M. Liu et al.

ascospores that are cylindrical, slightly tapering towards

ends, 10–16� 2.5 mm, or ovoid 8–10� 3 mm (Fig 7D).

Anamorph may or may not co-exist in the same stromata

with teleomorph. Anamorphic stromata white (Figs 4I, 7F–G)

in fresh specimens, yellowish white to orange white in old

specimens; flattened pulvinate, usually very thin, 0.2–0.7 mm

thick, 1–3 mm diam, surrounded by a hyaline hypothallus up

to 1.5 mm wide. Stroma surface minutely tomentose, covered

with confluent conidial masses that are deep yellow (4A6) to

orange yellow (4A7). Conidiomata occur as simple depressions

in the stroma, 3–13 per stroma, forming a ring (Fig 7G) or irreg-

ularly (Figs 4I, 7F) arranged. Conidiogenous cells (Fig 7I), arising

singly or in a cluster of 3–5 from thick-walled hyphae, some-

times branched, cylindrical, slightly tapering towards the

apex, truncate, 7–22� 1–1.5 mm. Conidia fusoid (9–)11–14

(–16)� 1.5–2 mm (Fig 7L), produced in copious slime. Paraphyses

arising from the hymenium of the conidioma, filiform, taper-

ing at the apices, 40–70 mm long (Fig 7H).

In culture, colonies 2–3.5 mm diam in three weeks at 23 �C

on PDA, white to yellowish white, pulvinate, surface tomen-

tose. Colonies cultured from ascospores often form hyphal

tufts in early stages. Colonies usually produce abundant vis-

cous conidial masses that become confluent, or thick cirri

that are concentrically arranged. Conidial masses pale yellow

(4A3), light yellow (4A4) to light orange (5A4) (Fig 4G). Conidio-

mata evident after conidial masses washed away. Similar in

shape to those in natural stromata; concave, with an opening

of 0.6–1.0 mm. Conidiophores and conidiogenous cells arise from

aggregated thick-walled hyphae (Fig 7J). Conidiophores typi-

cally penicillate or verticillate, branching 1–3 times, 30–

50 mm high, forming a hymenial layer. Conidiogenous cells slen-

der, 1.5–2 mm at widest point, 11–16 mm long, apices truncate,

or occasionally very long, reaching 70 mm, and resembling pa-

raphyses (Fig 7K). Conidia similar in size to those derived from

natural specimens, 10–15� 1.5– 2mm. Paraphyses occasionally

found in culture, 60–114 mm long.

Distribution: Cameroon, China, Ghana, India, Indonesia,

Malaysia, New Guinea, the Philippines, Thailand, and

Vietnam.Other specimens examined: Cameroon: Korup National Forest, Oct.

2003, G.J. Samuels & H.C. Evans, AFR114¼ARSEF 7616. Ceylon: Per-adeniya: On Schleichera tujuga, Jan. 1919, T. Petch, (K(M)128041);Salak, on Lasianthus sp., 1899, M. Raciborski (KRA-F1899-31, -32,-33) (type of Barya salaccensis). China: Guangdong: Dinghushan, 9Aug. 2004, B. Huang (DHS04080907¼CUP-CH 002607¼ARSEF7607¼CHN1); 10 Aug. 2004, B. Huang (DHS040810-10¼CUP-CH002620¼ARSEF 7686¼CHN3). Ghana: Central Region, Jukua dis-trict, Kakum National Park, wet semideciduous forest, N05 �210,W01 �230, elev. 280 m, 23 Oct. 2003, G.J. Samuels & H.C. Evans(AFR28¼ARSEF 7637). Indonesia: Java: Beng Breng, on leaves ofClerodendrum sp., M. Raciborskii 26, K(M)128056; Bogor BotanicalGarden, on Aleyrodidae on Aglaria odoratissima, 22 Mar. 1986,M.C. Rombach (220386-1) (ARSEF 2154) Tjibodas, in foliis coriaceissubemortuis, 5 Feb. 1897, (Naturhistorische Museum Wein No.16737) (holotype of A. javanica). Japan: Taom: On Quercus cuspidata,Aug. 1901, Tamura ((S) reg. Nr. F22458) (holotype of A. tamurai).Malaysia: Kuala Lumpur: on Aleyrodidae, 28 Mar. 1994, L.A. Lacey(94-41, ARSEF 4209). New Guinea: Kaiser Wilhelmsland, auf derUnterseite der Blatter von Ficus sp. ((S) reg. Nr F22442) (A. novogui-neenesis). Philippines: Luzon: Manila, San Francisco church localityor vicinity, on Anonaceae, 14 Feb. 1924, Mrs Clemens (BPI 635847); onFicus ulmifolia, Dec. 1911, P. W. Graff (BPI 635852); on Premna odor-ata, Dec. 1911, P. W. Graft, (K(M)128043); Isabella province, on

leaves of Ficus sp., Jan. 1924, M. Strong Clemens (4697,K(M)128049); Zambala province, Castillejos, on leaves, Mar. 1924,M. Strong Clemens (3275, K(M)128051); Laguna: Los Banos, college,on Ficus ulmifolia, 19 Dec. 1917, Torres (BPI 635849); On coccidson Litsea sp., Feb. 1932, G. O. Ocfemia, (K(M)128044) San Crispin,San Pablo, on coccids on Premna sp., Jan. 1932, M. S. Celino(K(M)128046) Cebu Island: Cebu, on leaves of Ficus sp., May 1924,M. Strong Clemens (6210, K(M)128048); Mindanao: Davao province,Mt. Apo, on leaves probably Strongylodon sp., Jan. 1924, M. StrongClemens (5656, K(M)128050). Singapore: On leaves of Smilax barbata,T. Petch, (K(M)128052). Sri Lanka: Nuwara Eliya, on leaves, 26 June1927, ex herb T. Petch (R238, K(M)128055). Thailand: sine loc., onscale insects and whitefly, 28 Aug. 1956, E. F. Vestal, (K(M)128040)Northeastern Thailand (BCC1454); Western Thailand (BCC2163); Cen-tral Thailand (BCC2227); Eastern Thailand (BCC2175).

Notes: This species closely resembles A. aleyrodis/H. libera.

Petch (1921) stated that the two could be distinguished by

the slightly thinner stromata and shorter paraphyses of A. pla-

centa. In our examination, the pulvinate stromata of A. placenta

tended to be thinner and the tubercles (H. raciborskii) usually

develop around the peripheral part of the anamorphic stro-

mata, while in H. libera the teleomorph and anamorph are

rarely formed in the same stroma. The conidiomatal paraph-

yses reveal differences in length between two species. In

A. aleyrodis the paraphyses may reach 113 mm; in A. placenta

they are not longer than 80 mm. Paraphyses are not ordinarily

observed in culture for either species. In addition, H. raciborskii

produces a proportion of ovoid part spores that are shorter

and fatter than usual, but this is not observed in H. libera. In

A. placenta, conidiophores arise from the ends of hyphal tufts,

and are penicillate or verticillately branched, while in A. aleyr-

odis, in addition to the aforementioned form, more conidioge-

nous cells arise singly from hyphae.

The type of H. warneckiana in B was probably destroyed

during World War II (Burghard Hein, pers. comm.). The ori-

ginal description by Hennings (1905) agrees completely with

H. raciborskii.

The original description of A. novoguineenesis by Hennings

(1898) is consistent with the characteristics of A. placenta, except

that the statedwidth of the conidia (0.3–0.4 mm) is narrower than

that of the A. placenta (1.5–2 mm). Our measurements of conidia

from the type (S) were (10–)13–15 (–17)� 1.5–2(–2.5) mm, which

falls in the range for those of A. placenta. The stromata are small

(1 mm diam), had abundant paraphyses measuring 40–

70� 1.5 mm, and conidiogenous cells 12–17� 1.5–2 mm. As these

characters are consistent with A. placenta, we consider A. novo-

guineenesis a later synonym of A. placenta.

The type of A. javanica (W 16737) is in poor condition with

only a single stroma on the leaf. Petch (1921) observed that

the morphology matched some forms of A. placenta, and we

agree with Petch’s conclusion that A. javanica is a synonym of

A. placenta. H. javanica is not the teleomorph of A. javanica, but

of A. coffeae, which has brownish stromata, unlike A. javanica.

We examined the type of A. tamurai (S, F22458). The stroma

shape resembles that of A. placenta. The colour of the conidial

mass had faded to yellow, presumably through aging. Petch’s

(1921) description of its original colour as reddish orange is

consistent with A. placenta. Other characters, such as the

size of conidia (8–12� 1.5–2 mm) and the length of paraphyses

(50 mm) are also consistent with those of A. placenta. We there-

fore consider these names to be synonyms.

Page 15: Aschersonia sp

Aschersonia aleyrodis and its allies 551

Another species that resembles A. placenta is A. australien-

sis. A syntype specimen from B collected by Pritzel from North

Queensland has the general shape of A. placenta with white

pulvinate stromata and circularly arranged conidiomata.

However, as Petch (1921) pointed out, the conidia are distinc-

tively small, 5–8� 1.5 mm, whereas in A. placenta they are typ-

ically over 9 mm long. A syntype collected by Diels from New

Zealand has a different stroma shape with three tubercles; it

is probably a different species. We retain A. australiensis as

separate species.

8. Hypocrella rhombispora Miao Liu & K. T. Hodge,sp. nov.

Anamorph: Aschersonia sp.Stromata 2–2.5 mm diametro, lutescentia vel pallide aurantiaca,pulvinata, subtuberculata ad basem constricta. Perithecia in stro-mate dense dispersa, inclusa. Ostiola non procurrentia, brunnes-centi-flava. Asci cylindrici in apice pileati. Ascosporae filiformes,in partisporas dimorphicas abrumpentes, nunc fusoideas inambobus extremis acutas 10–14� 2–3 mm, nunc cylindricas inambobus extremis obtusas, 7–12� 1.5–2.5 mm, in toto gutulatae,in medio ubi guttulae accumulatae plerumque tumidas. Anamor-pha in eodem stromate ac teleomorpha vel non. Stromata ana-morphica alba, pulvinata vel conico-pulvinata vel scutata, insuperficie minute pruinosa. Hypothallus saepe nullus. Conidiomaannulatim disposita, sparsa vel in massam reticulatam, conidia-lem pallidam vel sublutescentem. Conidia rhombiformia, 9–14� 2.5–3 mm. Coloniae in PDA moderate auctae, compactae,firmae, coriaceae, griseo-albae vel lutescenti-albae, in superficieminute tomentosae, massis conidialibus copiosis, viscosis, vivideluteis obsitae. Forma conidiorum in cultura varior: plurima coni-diorum rhombiformia vel aliquae tumidissima. Nec paraphysesnec synanamorpha hirsutelloidea visae.

Typus: Honduras: Departamento Yojo: Los Pinos, Parque NacionalCerro Azul-Meambar, 850 m elevation, 3 Sept. 2004, P. Chaverri &P. A. Sheikh PC691(¼CUP 067548 holotypus).

(Figs 4J–L, 8)

Stromata pale yellow (4A3) to pale orange (5A3), pulvinate and

slightly tuberculate, 2–2.5 mm diam, 0.8–1.4 mm thick, slightly

constricted at base, sometimes surrounded by hypothallus.

Stromatal tissue dense textura intricata (Fig 8C). If present,

hypothallus narrow, 0.6 mm wide, and minutely tomentose.

Perithecia densely arranged in the stroma, embedded, ostioles

not projecting, brownish yellow (5B7); in section 300–450 mm

high, 210–300 mm at widest point. Asci subcylindrical, widest

at midpoint, slightly narrower at both ends, 148–296 mm

long, 6–14 mm at widest point, 5–8 mm at apices. Ascospores ini-

tially filiform, slightly shorter than perithecia, 1–1.5 mm diam,

dividing into part spores (Fig 8D). Part spores fusoid, acute at

both ends, 10–14� 2–3 mm, or others cylindrical with blunt

ends, 7–12� 1.5–2.5 mm; guttulate, usually swollen at mid-

point where guttules accumulate (Fig 8E). Paraphyses absent.

Anamorphic stromata (Figs 4L, 8F–G) white, thin pulvinate,

Hemi-globose or scutate with a hemispheric central region

abruptly attenuating and towards the edge (Fig 4L); 1–3 mm

diam, 0.2–0.7 mm thick; surface minutely pruinose. Hypothal-

lus, if present, 0.2–0.8 mm in width. Conidiomata 4 to numerous,

arranged concentrically, scattered, or forming a reticulum on

conical part of stroma. Conidial mass pale to light yellow (3A4–

4A4), in conidiomata or accumulating as discrete drops over

the ostioles, not confluent. Stromatal tissue textura intricata,

near conidiomata (about 75 mm below the hymenia), becoming

more dense (as approaching textura epidermoidea or textura

oblita); hyphal walls markedly thickened, 1–3 mm thick for hy-

phae 3–6 mm in diam (Fig 8H–I). Conidiomata (Fig 8H) ‘U’-shaped

or convolute in section, ostioles 50–180 mm wide. Hymenium

lining inner surface of conidioma. Conidiogenous cells arising

singly from thick-walled hyphae, narrow cylindrical, not

branched (Fig 8I), tapering near truncate apices, 8–12�1.5–2 mm. Conidia 9–14� 2.5–3 mm, inflated at the midpoint

(2.5–3 mm wide) and tapering at both ends, forming two slender

2–4 mm ends (Fig 8K–M). Paraphyses absent.

Colonies (Fig 4J) on PDA 20 mm diam after four weeks at

23 �C, thick pulvinate, moderately compact, firm and leathery,

greyish white (1A1–1B1) to yellowish white (3A2), surface mi-

nutely tomentose, smooth to radially wrinkled, covered with

deep yellow (4A8) conidial masses. Conidial masses abundant,

formed as numerous small viscous to solid drops, some of

which fuse together. In some cases the hyphae congregate to

form tubercle-like tufts covered with numerous yellowish

white (3A2) drops of liquid exudate. Hyphae 3–6 mm wide with

thickened wall 0.5–1 mm thick. No conidiomata formed, conid-

ial masses directly produced from surface of colony.

Conidiogenous cells arising laterally from hyphae, single,

unbranched; or in clusters. Conidiogenous cells strongly

constricted at the basal septum, those arising laterally

from hyphae are longer than terminal conidiogenous cells, 8–

12(–15)� 2–2.5 mm (Fig 8J). Conidia markedly inflated at the mid-

point and tapering at both ends, 8.5–12 (–17)� 2–3 mm; in some

cultures, extremely wide conidia produced, ovoid in the cen-

tre, contain a single very large guttule (4–6� 3–6 mm), and

have two elongated ends measuring 2–3 (–5) mm (Fig 8K–M).

Neither paraphyses nor Hirsutella-like synanamorph observed.

Distribution: Costa Rica, Honduras, Mexico, and Puerto Rico.Specimen and culture examined. Costa Rica: Heredia: O. T. S. La

Selva Biological Station, Camino Cantarrana, on Cyclanthus biparti-tus, 19 June 2002, M. Liu CR07; CUP 67296¼ARSEF 7511); 5 Jan. 2004,P. Chaverri, (PC466¼CUP 067537, PC467¼CUP 067538); beside en-trance to Plantation RCC, 20 June 2002, M. Liu ML44-3, (cultureCR32¼CUP 067346); Puntarenas, Las Cruces Biological Reserve,Wilson Botanical Garden, large loop of jungle trail, on Guarea rho-palocaipa, 4 July 2002, M. Liu, ML64 (culture CR34¼CUP 67369).Honduras: Yojoa: Los Pinos, Parque Nacional Cerro Azul-Meambar,850 m elev., 3 Sep. 2004, P. Chaverri & P. A. Sheikh, (PC691¼CUP067548, PC696¼CUP 067550, PC698¼CUP 067551); Copan: SantaRita, Reserva Pena Quemada, 9 Sep. 2004, P. Chaverri & P. A. Sheikh.Mexico: Veracruz: Amayaga, Catemaco, 500 m elev., 14 Dec. 2003,P, Chaverri & J. Garcıa-Alvarado, (PC460¼CUP 067534). USA: PuertoRico: Between Mayaguez and Maricao, beside road 105 15 Dec.2003, M. Liu & Z.D. Wang, ML164 (CUP-PR 4406; Ex-type cultureML164¼ARSEF 7390; Guajataca Forest, trail no. 9, on fern, 18Dec. 2003, M. Liu & Z.D. Wang ML201-1,ML201-3, ML201-5a (CUP-PR 4437¼ARSEF 7395, ARSEF 7399, ARSEF 7400).

Notes: The most distinctive characters of this species are

the shape of the part spores and conidia, both of which are

distinctly inflated in the middle. These characters are shared

by a closely-related complex of species referred to H. phyllo-

gena/A. basicystis. Hypocrella phyllogena has an orange stroma

of a globose head and a narrower neck, upon which the asex-

ual (A. basicystis) fruiting structure usually appears. In H. rhom-

bispora, the asexual and sexual states often occur on different

stromata. The teleomorphic stroma is white and minutely tu-

berculate. The conidiomata are scattered over the anamorphic

stromatic surface.

Page 16: Aschersonia sp

552 M. Liu et al.

Fig 8 – Hypocrella rhombispora. (A) Minutely tuberculate teleomorphic stroma with slightly narrowed base (CUP 067548). (B)

Perithecium in section, with the ostiole slightly erumpent. (C) Compact tissues around perithecium. (D) Asci containing

ascospores that disarticulate to form part ascospores. (E) Ventricose part ascospores with rounded or acute ends. (F–G)

Anamorphic stromata (CUP-PR 4437): the conidiomata are scattered and produce discrete conidial masses. (H) Section of

conidioma showing the hymenium and conidia; paraphyses are lacking, and the tissues surrounding the conidioma are

compact. (I) Hymenium, showing a palisade of conidiogenous cells and compact surrounding tissues. (J) Conidiogenous cells

in culture are flask-shaped and slightly narrower at the base. (K–M) Ventricose conidia showing variation in width among

several specimens. Bar [ 500 mm for Figs A, F–G; 100 mm for Fig B; 10 mm for Figs C–E, H–M.

9. Hypocrella turbinata Petch, Ann. Roy. Bot. Gard.Peradeniya 5: 535 (1914).

Anamorph: Aschersonia turbinata Berk., Ann. Mag. Nat. Hist.,

ser.2 9: 192 (1852).

(Fig 3D)

Notes: Young H. turbinata specimens produce small

cylindrical stromata similar to those of A. cubensis. The

latter two species can easily be distinguished from

specimens of A. aleyrodis that have scutate stromata (Fig 6E)

by the shape of the conidia. In A. turbinata and A. cubensis,

the conidia are wider (Fig 3D); in A. aleyrodis they are narrowly

fusoid (Fig 3A).

10. Hypocrella zhongdongii Miao Liu & K. T. Hodge,Mycol. Res. 108: 820 (2005).

(Fig 3B)

Anamorph: Aschersonia incrassata Mains, J. Insect Pathol. 1: 46

(1959).

Note: This species most closely resembles H. andropogonis/

A. andropogonis; both A. incrassata and A. andropogonis are com-

mon yellow-spored species in the neotropics. A. incrassata can

be distinguished by the distinctive thickened walls at the ends

of conidia. Further comparison of these two species and the

evolutionary relationships of H. zhongdongii with other species

in the genus were discussed by Liu & Hodge (2005).

Page 17: Aschersonia sp

Aschersonia aleyrodis and its allies 553

Discussion

Based on morphological and phylogenetic analysis, six species

with white pulvinate stromata are recognized, A. aleyrodis (tele-

omorph: H. libera), A. andropogonis (H. andropogonis), A. placenta

(H. raciborskii), A. incrassata (H. zhongdongii), A. basicystis (H. phyl-

logena), and one new species, described here as H. rhombispora

(with its anamorph). The stromata of H. phyllogena are orange

and relatively dense when mature, but white and effuse during

early stages of development and asexual sporulation.

Most phylogenetic species reflect Petch’s (1921, 1925) con-

cepts , and appear as strongly supported clades. However,

the relationship between H. libera/A. aleyrodis and H. racibor-

skii/A. placenta is not resolved. Further studies using faster

evolving genes and more intensive analyses have resolved

their sister relationship (Liu et al., pers. obs.), supporting

Petch’s hypothesis that these two similar fungi from the

New World and the Old World represent different species. Ac-

cordingly, we treat them here as distinct species.

An examination of the phylogenetic distribution of mor-

phological characters within the group identified many

apomorphies. Descriptive morphological characters (autapo-

morphies) that characterize species include the shape of tele-

omorphic stromata, shape and arrangement of tubercles

containing perithecia, shape of part ascospores, shape of ana-

morphic stromata, presence/absence of a rim around the ori-

fices of conidiomata, arrangement of conidial masses on the

stromata, colouration of conidial masses, shape of conidia

and presence/absence of paraphyses. Except for the rim

around the conidiomatal orifices, all other characters were

used by Petch (1921) in differentiating species. It is worth not-

ing that the presence or absence of conidiomatal paraphyses

may be diagnostic, but it has been questioned as a criterion

to separate Aschersonia into two subgenera (Liu & Hodge 2005).

The shape of the conidioma (called a pycnidium by Petch

1921) and its orifice were among the characters used by Petch

to differentiate species. Although the presence/absence of

a rim around the orifice is useful for differentiating certain

species, such as A. andropogonis and A. incrassata, the shapes

of the conidiomata and orifices are not constant within

each of these six species, and we consider them to be of ques-

tionable use. Their morphology appears to vary with the de-

gree of maturity of the conidioma. Petch (1921) observed two

types of conidiomatal formation in Aschersonia. In the first

type the conidiophores developed on a small actively growing

area of the surface of stroma, which gradually became invag-

inated as it expanded. In the second type, a conidioma was

formed as a locule within the stromata and later broke

through to the surface. Aschersonia species with white pulvi-

nate stromata conform to Petch’s first type of development.

In this group, the stromata appear to develop from a thin layer

into a thicker pulvinate one. The thinner the stroma, the wider

the conidiomatal orifice. On a thin stroma, conidiomata ap-

pear as widely open shallow depressions of the surface (Figs

4F, I); as the stroma becomes thicker, the growth of the sur-

rounding stromatal tissue constricts the opening and forms

conidiomata that are V-shaped, U-shaped, globose, tubular,

or irregularly concave (Figs 5G, 6G, 7H). Several of these

shapes might be found in a single species i.e. A. aleyrodis,

A. andropogonis and A. incrassata, etc, depending on stromatal

thickness and degree of development. Thus we cannot con-

sider conidiomatal shape useful for differentiating species in

this group. Conversely, for some species outside our focal

group (e.g. A. turbinata), the situation is different. The stromata

do not develop from a thin layer, instead they begin as small

masses and develop into cylindrical to complex structures. A

vertical section of a small cylindrical A. turbinata stroma re-

veals that the irregularly folded hymenium develops inside

the stroma under a small orifice. Several characters that pre-

dict phylogenetic relationships (synapomorphies) were found.

These include the white, effuse anamorphic stroma that is

typical of A. aleyrodis and allies (Fig 1, character A), Other syn-

apomorphies include the arrangement of conidial masses on

the stromata or colony surfaces. This character separates all

white stroma species into two clades, i.e. a clade with conflu-

ent masses (A. aleyrodis and A. placenta; Fig 1, character B) and

a clade in which conidial masses are discrete (A. incrassata,

A. andropogonis, Aschersonia anamorph of H. rhombispora, and

A. basicystis; Fig 1, character D.) The former clade is also united

by the character of cylindrical tubercles containing perithecia

(Fig1, character C). Ventricose conidial shape (Fig 1 character F)

defines a clade composed of A. basicystis and H. rhombispora;

the formation of a rim around the conidiomatal orifices de-

fines a clade of A. andropogonis and A. incrassata. The colour

of the conidial mass is not phylogenetically informative: taxa

producing yellow conidial masses, for example, do not form

a monophyletic group (Fig 1). The insect hosts of this genus

are restricted to the families Aleyrodidae and Coccidae in the

order Hemiptera (Petch 1921, Mains 1959, Evans 1990, Meekes

et al. 2002). One Aschersonia species may attack a wide range

of species within an insect genus; conversely, one insect

species in Aleyrodes or Lecanium can be attacked by many

Aschersonia species (Petch 1921). Petch (1921) separated Ascher-

sonia into two subgenera based on host (whitefly versus scale

insect) and the presence/absence of hymenial paraphyses.

These subgenera of Aschersonia were considered to correspond

with the two subgenera of Hypocrella. Later authors have ques-

tioned Petch’s subgeneric concepts (Dingley 1954, Liu & Hodge

2005). Because of the difficulty in identifying the insect hosts,

the ecological host range of Aschersonia species has not been

sufficiently studied. Whether or not there is host specializa-

tion or coevolution in Hypocrella/Aschersonia is a question

waiting for an answer.

Acknowledgements

We thank the staff at B, BPI, CUP, FH, HMAS, K, KRA MICH,

PAD, and S for kindly loaning specimens; ARSEF, BCC, and

CBS for providing fungal isolates; the US Forest Service for per-

mission to collect fungi in the Caribbean National Forest (El

Yunque), and the National Biodiversity Institute (INBio) for fa-

cilitating collecting by ML in Costa Rica. Our thanks also go to

all of the people who have provided specimens or cultures:

Mary C. Aime, Joseph F. Bischoff, Harry C. Evans, Gary J. Sam-

uels, and Christopher L. Schardl; and also people who have fa-

cilitated our collecting in different places: B. Jean Lodge,

Sharon Cantrell, Sandra Maldonado, Miriam Salgado in Puerto

Rico; Juventino Garcıa Alvarado in Mexico, Phil Arneson in

Page 18: Aschersonia sp

554 M. Liu et al.

Honduras, Emilia Garcıa y Diego De la Quintana in Bolivia, Luis

Diego Gomez in Las Cruces, CR; Clayton McCoy, Philip Stansly,

Lee Mitchell, Stephan Brown, Ronald Cave, Lavern W. Timmer,

and James Kimbrough in Florida; Zengzhi Li and Bo Huang in

China. The plates were prepared by Kent Loeffler. Comments

from two anonymous reviewers improved the manuscript.

This project was supported by the National Research Initiative

of the USDA Cooperative State Research, Education and Exten-

sion Service, grant no. 2002-35316-12263, and by the National

Science Foundation under Grant no. 0212719 to K.T.H.

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