Soft Scale Insects

427 Pages·1997·45.096 MB·English

by  Y. Ben-Dov

Preface
Even four or five decades ago, entomologists embarking on a study on soft scale
insects would have encountered a scarcity of general text books or comprehensive
treatese of the family, as a starting point for their research. At this time, the available
knowledge and data were either scattered among numerous articles or regional
monographs or were in obsolete books such as those of M.E. Fernald (1903)
A Catalogue ofthe Coccidae ofthe Worm and A.D. MacGillivray (1921) The Coccidae.
Since then, the availability and comprehensiveness of data on soft scale insects has
been greatly increased by a number of valuable publications, including bibliographies
covering all the Coccoidea, such as those of Morrison and Renk (1957), Morrison and
Morrison (1965), Russell et .la (1974) and Kosztarab and Kosztarab (1988), while
several regional monographs have also become available, such as those for the former
USSR (Borchsenius, 1957); Central Europe (Kosztarab and Kozdr, 1988); Tropical
South Pacific (Williams and Watson, 1990); Florida (Hamon and Williams, 1984) and
California (Gill, 1988).
The present volumes are intended to be a further step towards providing
comprehensive information on soft scale insects. Together with the recently-published
monographs, Ben-Dov (1993) A systematic Catalogue of the Soft Scale Insects of the
Worm and Hodgson (1994) The Scale Insect Family Coccidae: an Identification Manual
to Genera, it is hoped that this volume will cover almost the entire spectrum of the
knowledge on the soft scale insect family, Coccidae.
For technical reasons this work has been published in two Volumes, Volumes 7A
(comprising Sections 1.1.1 to 1.4.2)and Volume 7B (comprising Sections 2.1 to
3.3.18). This needs to be borne in mind when looking up cross references.
In these volumes we have followed the pattern of previous books in the Elsevier's
series of 'Worm Crop Pests' and so the information is divided into three parts:
Part 1. The Soft Scale Insects presents a comprehensive account of the morphology,
systematics, phylogeny, biology, physiology, ecology and techniques for their
scientific study. The majority of soft scale species are pests of agricultural crops,
although several species are ranked as beneficial insects, thus this aspect is also
treated here.
Part 2. The Natural Enemies covers the pathogens, predators and parasitoids.
Part 3. Damage and Control opens with an account on the major soft scale pests of
agricultural crops in the world. Because of the hazardous environmental effects of
synthetic pesticides, these have not been treated here but a Section on Insect
Development and Reproduction Disrupters is included. This Part concludes with a
series of eighteen Sections on the coccid pests of the major crops in the world.
Many of the contributing authors to these volumes have also reviewed various
sections of the book and we are extremely grateful for their help. We are also very
grateful to other colleagues who kindly consented and reviewed sections at our
request, these are:
Preface
Dr. Israel Ben-Zeev (Ministry of Agriculture, Bet Dagan, Israel); Dr. Ezra Dunkelblum
(The Volcani Center, Bet Dagan, Israel); Dr. Isaac Ishaaya (The Volcani Center,
Bet Dagan, Israel); Dr. Robert Minckley (Department of Entomology, Auburn
University, Alabama, USA); Dr. John S. Noyes (The Natural History Museum,
London, England); Dr. James Pakaluk (Systematic Entomology Laboratory, USDA,
Washington, D.C., USA); Dr. Andrew Polaczek (International Institute of Entomology,
London); Dr. Michael Schauff(Systematic Entomology Laboratory, USDA, Washington,
D.C., USA); Dr. Zvi Solel (The Volcani Center, Bet Dagan, Israel);
Dr. Gillian W. Watson (International Institute of Entomology, London) and
Dr. Douglas J. Williams (International Institute of Entomology, London, England).
We are extremely grateful to Avas Hamon, Florida Department of Agriculture and
Consumer Services, Gainesville, Florida for permission to use his photographs on the
cover.
Special thanks are due to the British Council for a grant towards travel expenses for
the final editing of these volumes.
Thanks are due to our colleague Mme. Dani~le Matile-Ferrero (Mus6um National
d'Histoire Naturelle, Paris) who kindly checked and corrected the spelling of most of the
references in French, but any errors still present are our responsibility.
We are grateful to our Institutes for the time that we have been allowed to give to
this project. CH would particularly like to thank Professor Dennis Baker for allowing
free access to the Departmental facilities and Dr Mike Copland, Mrs Sue Briant and
Mrs Margaret Critchley for their help in various ways.
Lastly, we would like to thank our respective wives, Yehudith Ben-Dov and
Charlotte Hodgson, for their patience, support and understanding.
We hope you will find this book helpful.
Yair Ben-Dov Chris J. Hodgson
Cover photographs. Left: Coccus viridis )neerG( :eaniccoC( ,)iniccoC lasrod view, tluda .elamef Flat dna
elap green ni life. Note ,llams black elpmis eyes ta roiretna )detniop( end, black depahs-U dotted line no
musrod gnikram( noitisop of yratnemila )lanac dna eht owt pale gnitaidar senil no right edis desuac yb eht
etihw xaw ni eht citamgits sevoorg htaeneb .retnev :elddiM Inglisia vitrea llerekcoC ,)eaniccocoidraC( lasrod
,weiv tluda .elamef nworb-hsiddeR ni life. Note yssalg ,tset ni owt sevlah detarapes yb a tcnitsid lanidutignol
;erutus lanigram setae dna white xaw ni citamgits grooves clearly visible. Right: Ceroplastes dugesii
nietsnethciL ,)eanitsalporeC( laretal-osrod view, tluda .elamef Note kciht test desopmoc ylniam of hsitihw
"tew" wax, tub with llams saera of retihw "yrd" xaw yllaidem no musrod dna detaicossa with each citamgits
;aera anal setalp neddih no right edis of .etalp
XV
Contributors to Volume 7B
YAIR BEN-DOV
Department of Entomology, Agricultural Research Organization, The Volcani Center,
Bet Dagan 50 250, Israel
COLIN A.M. CAMPBELL
Institute of Horticultural Research, East Malling, Maidstone, Kent, ME19 6BJ, UK
ALASTAIR J.M. CARNEGIE
Formerly: South African Sugar Association Experiment Station, P.O. Mount
Edgecombe, Mount Edgecombe, Natal 4300, South Africa
TOCK HING CHUA
Department of Zoology, University of Malaya, 59100 Kuala Lumpur, Malaysia
MICHAEL J.W. COPLAND
Department of Biological Sciences, Wye College, Wye, Ashford, Kent, TN25 5AH, UK
BI~LA DARVAS
Plant Protection Institute, Hungarian Academy of Sciences, Herman Otto ut. 15,
P.O. Box 102, Budapest, H-1525, Hungary
HARRY C. EVANS
CAB International Institute of Biological Control, Silwood Park, Buckhurst Road, Ascot,
Berks SL5 7TA, UK
RAYMOND J. GILL
Plant Pest Diagnostics Center, California Department of Food & Agriculture,
3294 Meadowview Road, Sacramento, California 95832-1448, U.S.A.
DAVID J. GREATHEAD
Centre for Population Biology, Silwood Park, Buckhurst Road, Ascot, Berks,
SL5 7TA, UK
KEITH M. HARRIS
Formerly: International Institute of Entomology, 56 Queen's Gate, London,
SW7 5JR, UK
MOHAMMAD HAYAT
Department of Zoology, Aligarh Muslim University, Aligarh 202001, India
CHRIS J. HODGSON
Department of Biological Sciences, Wye College, University of London, Wye, Ashford,
Kent, TN25 5AH, UK
xvi Contributors
NIGEL L. HYWEL-JONES
National Biological Control Research Center, P.O.Box 9-52, Kasetsart University,
Bankhen, Bangkok 10900, Thailand
MICHAEL KOSZTARAB
Department of Entomology, Virginia Polytechnic Institute and State University,
Blacksburg, Virginia 24061, U.S.A.
SEAN T. MURPHY
CAB International Institute of Biological Control, Silwood Park, Buchhurst Road, Ascot,
Berks, SL5 7TA, UK
GIUSEPPINA PELLIZZARI
Istituto di Entomologia Agraria, Facolta di Agraria, Agripolis, Via Romea,
35020 Legnaro - radova, Italy
DOUGLAS G. PFEIFFER
Department of Entomology, Virginia Polytechnic Institute and State University,
Blacksburg, Virginia 24061, U.S.A.
DAVID J. PONSONBY
Science Department, Canterbury Christ Church College, North Holmes Road,
Canterbury, Kent, CT1 1QU, UK
GERHARD L. PRINSLOO
Plant Protection Research Institute, Private Bag X134, 0001 Pretoria, South Africa
MIKE ROSE
Biological Control/Entomology, Montana State University, Bozeman, Montana
59717, U.S.A.
STEVE STAUFFER
Biological Control Laboratories, Department of Entomology, Texas A&M University,
College Station, Texas 77843-2475, U.S.A.
ELIAHU SWIRSKI
Department of Entomology, Agricultural Research Organization, The Volcani Center,
Bet Dagan 50 250, Israel
GENNARO VIGGIANI
Dipartimento di Entomologia e Zoologia Agraria, Facolta di Agraria, Via Universith,
100, 80055 Portici, Italy
MANES WYSOKI
Department of Entomology, Agricultural Research Organization, The Volcani Center,
Bet Dagan 50 250, Israel
Soft Scale Insects - Their Biology, Natural Enemies and Control (7B)
Y. Ben-Dov and C.J. Hodgson (Editors)
(cid:14)9 1997 Elsevier Science B.V. All rights reserved.
2.1 Entomopathogenic ignuF
HARRY C. EVANS and NIGEL L. HYWEL-JONES
INTRODUCTION AND HISTORICAL REVIEW
This review aims to identify those fungi which have been recorded as pathogens of
Coccidae, to comment on their taxonomy and biology and then to consider their potential
in biological control systems. A review of the entomopathogenic fungi of true scale
insects runs into taxonomic problems which must first be addressed to an entomologist.
Almost all work on these fungi has been by mycologists specialising in plant pathology
and with a largely botanical training. Further, much of the literature is in excess of 70
years old. Set against this background, the modem reviewer can often only guess at
what the terminology really meant.
With the early work, especially that of the nineteenth century, being by botanically-
trained mycological taxonomists there was no appreciation that these fungi were insect
pathogens. Many epithets reflect the plant on which the fungus was found since it was
generally assumed that these were plant pathogens. It was not until Webber (1894)
studied the fungi associated with insects of Citrus in Florida that their insect-pathogenic
nature became apparent. He recognised that Aschersonia turbinata Berk. was a pathogen
of Ceroplastesfloridensis Comstock and that Aschersonia cubensis Berk. and Curt. was
pathogenic to Lecanium hesperidum (= Coccus hesperidum L.). In describing
Aschersonia aleyrodis Webber (on Dialeurodes cirri (Ricco)), Webber (1894) provided
the first epithet which reflected the true host relationship of the fungus.
A key worker with these fungi, who did much to collate records, was T. Petch, a
mycologist who worked in Sri Lanka from 1905-1928. His attention to insect fungi in
general was undoubtedly stimulated by the work of his predecessor, J. Parkin,
mycologist at the Royal Botanical Gardens, Peradeniya (Parkin, 1906). Parkin, in turn,
was introduced to these fungi by the entomologist E.E. Green, who worked with scale
insects and was curious as to what the fungi were. Petch (1921a), in a footnote to his
Presidential address to the British Mycological Society, which reviewed the 'Fungi
parasitic on scale insects', stated that: 'from a mycological standpoint, it is convenient
to include the fungi parasitic on Aleyrodidae with those on the true scale insects
(Coccidae)'. In all Petch's subsequent publications, he continued to think in this
manner. The terminology becomes further confused from an entomological standpoint
because Petch included many genera from the Diaspididae in his broad terms of
'Coccidae' or 'coccid'. In his 1921 address, Petch mentioned "scale" host over 70
times. However, in only 25 of these can the host reliably be placed as a scale insect of
the family Coccidae. The rest were either Diaspididae or Aleyrodidae.
Since Petch's pioneering work, several mycological taxonomists have reported on
the entomopathogenic fungi of 'scale insects'. Very rarely was an entomologist involved
in the identification of the host. To a greater or lesser extent, these mycologists adopted
Petch's entomological terminology, adding further to the confused state of affairs.
Section 2.1 references, p. 22
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Where a host is given to genus, we can place this in the correct family. However, in
many references, terms such as 'scale insect', 'coccid' or 'Coccidae' are used. The first
term we accept can include Aleyrodidae, Coccidae and Diaspididae; the second and third
terms may include Coccidae and Diaspididae.
Personal experience shows that often the host is completely overgrown and
destroyed by the fungus making certain identification impossible (Evans and Hywel-
Jones, 1990). Furthermore, healthy scales remaining on the leaf cannot be relied upon
for a correct identification. Often the fungus is so specific that it may obliterate one
species while leaving another untouched. This possibility was apparent to Petch (192 lb),
who noted that 'if a Lecanium and a Lepidosaphes occur together on the same leaf, a
lecaniicolous Hypocrella may destroy all the individuals of the Lecanium leaving only
the Lepidosaphes'.
Before this Section goes any further, it has to be accepted that the records presented
in Table 2.1.1 are the most accurate the authors can compile. In our work we have
become aware that certain fungi have certain host associations. Rather than present all
records where 'scale insect' or 'coccid' are used as terms for the host, we have been
selective and included only those where we are sure that the host referred to was a true
member of the Coccidae. Where some studies have been made with respect to soft
scales as crop pests, we feel more credibility may be attached to host identifications, as
the pests are often well-known on that particular crop. However, we would be the first
to admit that the host identification has to be accepted with a pinch of salt in many cases.
In spite of the foregoing, the records presented will give the reader a clear
indication of the fungal taxa which are associated with soft scale insects and involved in
their population dynamics.
TAXONOMY
Much of the literature dates from the early part of this century and, since then, our
understanding of the taxonomy of fungi has changed considerably, with the result that
many of the names applied to these fungi are no longer meaningful in modem schemes
of fungal taxonomy. We have used the currently accepted name for a pathogen, but it
is beyond the scope of an article aimed at entomologists to include all synonyms. There
is still much revision that needs to be done and work is in progress to fully review these
fungi by making more collections, using modem techniques and with an emphasis on in
vitro cultural investigations.
Taxonomic studies in the past relied all too often on herbarium material only,
usually collected by a third party. When examined, this material was invariably dried
and preserved, with no record of its treatment. Consequently, many of the original
descriptions are based on dead material and, as such, these are seen now to bear little
relationship to the living material (Evans and Hywel-Jones, personal observations).
We have used our own field and laboratory observations to make modem
assessments of this material. Taxonomy is arranged according to the Dictionary of the
Fungi (Hawksworth et al., 1983). For the non-mycologist, the taxonomy of fungi is
complicated by having autonomous spore stages assigned to different genera. Thus, the
sexual state (teleomorph) will be named in one genus with the corresponding asexual
state or states (anamorphs) assigned to another genus (or genera). While mycologists
are the first to accept that this is an unwieldy system, the use of separate names is a
practical necessity in mycology to distinguish between morphologically distinct and
physiologically independent entities.
Full descriptions and illustrations of the genera concerned may be found in Samson
et al. (1988). Details provided are aimed at alerting entomologists to some of the
problems of mycology with a view to helping them to identify potential biological control
agents and where they may be found. A glossary is provided after the references for
some of the terms used in this Section.
Entomopatho g eni c fungi
MASTIGOMYCOTINA AND ZYGOMYCOTINA
These are the so-called lower fungi. Few have adapted to insects, with the
exception of Chytridiales and Blastocladiales (Mastigomycotina), which often occur as
egg pathogens, and the specialised Entomophthorales (Zygomycotina), which are chiefly
pathogens of Coleoptera, Diptera, Homoptera and Lepidoptera. As a stage of the insect
life-cycle, the egg is remarkably resistant to fungal attack and the Mastigomycotina stand
out among fungi as some of the few capable of breaching the exochorion. However, we
could find no records of egg-pathogenic fungi of Coccidae. This is not to say that they
do not occur. Nevertheless, given the size of the host material, examination of the leaf
with the naked eye is not likely to reveal these to the casual observer. Also, there are
no reliable accounts of Mastigomycotina being pathogenic to any other stage of the life-
cycle of the Coccidae. Conversely, they have been well documented as pathogens of
Diaspididae (Evans and Prior, 1990).
KEY TO THE GENERA OF FUNGI PATHOGENIC ON SPECIES OF COCCIDAE
la External structures (stromata) or mycelium prominent ............. 2
lb External structures absent; mycelium not prominent, when present, coarse,
hyaline, emerging from insect sutures; spores large .................
............................. Entomophthorales (Neozygites)
2a Host body covered by prominent, compact stroma ................ 3
2b Host body covered by loose mycelium, not stromatic .............. 6
38 Stroma not organised into erect structures ..................... 4
3b Stroma erect, typically club-shaped, organised into a sterile stalk and fertile head
region ..................................... Cordyceps
4a Stroma dense, cushion-like, brightly coloured .................. 5
4b Stroma loose to compact but never organised into an integral structure ......
................................... Verticillium (in part)
4c As above, but yellow, flask-shaped bodies visible in or on the stroma ......
......................................... Torrubiella
5a Brightly coloured slime emerging from within stroma; microscopically composed
of small (10 microns), spindle-like spores (may be associated with 5b) ......
........................................ Aschersonia
5b Stroma with irregular, pitted or undulating surface due to semi-erumpent
perithecia; microscopically containing long filiform spores enclosed in sac-like
structures ................................... Hypocrella
6a Mycelium with a powdery appearance ....................... 7
6b Mycelium not obviously powdery, may be associated with yellow flask-shaped
bodies ............................... Verticillium (in part)
7a Mycelium white to cream; very powdery ............... Beauveria
7b Mycelium typically in shades of white, yellow, pink or red; slightly to very
powdery .................................. Paecilomyces
Section 1.2 references, p. 22
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ENTOMOPHTHORALES
The Entomophthorales is an order containing mainly saprobic or broad-spectrum,
opportunistic and specialized insect pathogenic genera. Of the more than 100
entomopathogenic taxa described in this order, we can find only one record from
Coccidae.
Petch (1926b) discussed Empusa lecaniiZimm. (now Neozygites lecanii (Zimm.) Ben-
Ze'ev and Kenneth) from Lecanium viride (=Coccus viridis (Green)), noting its
occurrence in Sri Lanka, India and Java. Comparing these records with the original
description by Zimmermann (1901a, 1901b), who named it the "black scale insect
fungus", Petch concluded that the Indian fungus was similar to the Indonesian fungus but
was not a member of the Entomophthorales and was probably a composite of saprophytic
or weakly parasitic genera: Pythium, Cladosporium dna Macrosporium. Later, Petch
(1932a) discussed Neozygites lecanii briefly, whilst noting a fungus producing a similar
infection on aphids in the Philippines, and compared both fungi with the illustrations of
Empusafresenii Nowak. (now setigyzoeN fresenii (Nowak.) Ben-Ze'ev and Kenneth) in
Thaxter (1888). Waterhouse (1975) listed it amongst UK records as Entomophthora
lecanii, placing it in a group with smoky-coloured spores and considered that it was an
insufficiently described taxon. Ben Ze'ev and Kenneth (1982), however, re-described
the fungus, based on Zimmermann's and Petch's observations (but not on more recent
material) and proposed the new combination Triplosporium lecanii, although this was
subsequently transferred to the genus Neozygites (Ben-Ze'ev et al, 1987). We conclude
that more collections of the "black scale insect fungus" are required before its true
taxonomic status can be clarified.
ASCOMYCOTINA
This sub-division accounts for many of the insect pathogens named to date. It has
been our experience that these are well represented on soft scales. Interestingly, two
ascomycete genera which are important pathogens of Diaspididae - Nectria and
Podonectria (Evans and Prior, 1990) - are conspicuously absent from the records of
insect pathogenic fungi found on Coccidae. The following genera are recognised as
primary pathogens of soft scales.
Cordyceps Fries, Clavicipitales
This large genus (ca. 300 species) contains many highly specialised insect (and other
arthropod) pathogens. Most are pathogenic to Coleoptera, Hymenoptera and
Lepidoptera. A few have been recorded from Homoptera and there is one reliable
record from scale insects - Cordyceps clavulata. The host body is normally filled with
a compact mass of hyphae or hyphal bodies - the endosclerotium. One or more stalks
of parallel hyphae emerge from weak points on the exoskeleton. The fruit bodies
(perithecia) are either superficial or immersed in the stalk. The asci are thin-walled and
typically 8-spored; the ascospores are long, filiform and either remain whole or break
into part-spores at maturity. Release is either violent into the air or by oozing into water
films. The anamorphs of Cordyceps belong to several genera of the Deuteromycetes
such as Akanthomyces, Hirsutella, Hymenostilbe dna Verticillium (Samson et al., 1988).
specydroC clavulata (Schw.) Ellis and Everh. was first described in 1832 growing "on
the bark of oak trees" (Quercus palustris, .Q coccinea) in North America, and has since
been consistently recorded from that continent (Massee, 1895; Pettit, 1895; Seaver,
1911; Charles, 1941; Mains, 1958). Later, Peck (1874)reported it as parasitizing "the
flattened, discoloured, or blackened bodies of a scale insect (Lecanium) found on living
branches of Fraxinus in New York state". Pettit (1895), subsequently studied natural
infections on Lecanium sp. in stands of maple and on Lecanium fletcheri on red cedar,
Entomopatho g eni c fungi
and succeeded in culturing the fungus and re-infecting healthy scales. In the UK,
however, the fungus had already been described in 1861 as Cordyceps pistillariiformis
Berk. and Br. from "elm twigs" (Cooke, 1892). Cooke (1892) referred to it colloquially
as the "grey coccus club" and recognized that the fungus was actually growing on a
"female Coccus" and not on the tree host as originally suspected. Soon after, Massee
(1895) confirmed the parasitic nature of .C clavulata based on the UK collections from
scale insects on Wych elm (Ulmus montana). He recognized the synonymy of .C
pistillariiformis and listed further North American records on dead scale insects
(Lecanium) from branches of Fraxinus dna Prunus in the USA, as well as from Clethra
and Carpinus in Canada. There is little doubt, therefore, that the East European records
(Table 2.1.1.) assigned to .C pistillariiformis are, in fact, referable to .C clavulata.
On each insect, there are several club-shaped stromata, 2-4 mm long, with cylindric-
ovoid heads. These are brownish-black and verrucose because of the crowded, erumpent
perithecia. The mature, thread-like ascospores do not split into part-spores. The
anamorph was redescribed by Petch (1933) as Hirsutella lecaniicola (Jaap) Petch, the
conidia being produced singly on needle-like conidiogenous cells borne on grey, narrow-
cylindrical stalks (synnemata) arising from the scale insect. The asexual state was
illustrated by Mains (1950) who transferred it to the genus Hymenostilbe. Later, Samson
and Evans (1975) revised this genus and re-assigned the anamorph of .C clavulata to the
genus Hirsutella. Both Hirsutella dna Hymenostilbe belong to the Hyphomycetes of the
Deuteromycotina.
Hypocrella Sacc., Clavicipitales
"This genus is one which may eventually be shown to be of common occurrence on
scale-insects. The species so far described have been found on leaf and stem surfaces
in the tropics. Quite possibly in some of these cases a scale-insect is the real host and
not the plant." (Parkin, 1906).
Although there is only one reliable record of Cordyceps from Coccidae, compared
with none from Diaspididae (Evans and Prior, 1990), the genus Hypocrella is common
on the true soft scale insects. It is one of the most specific of entomopathogenic genera
being restricted to members of the Aleyrodidae and Coccidae.
The stroma is an exosclerotium covering the host or forming a ring around it.
Stromatal shape is typically discoid to pulvinate, although more complicated forms also
occur (Fig. 2.1.1). The stromata are brightly coloured (white, yellow, orange, red or
salmon pink) in fresh material. However, many original descriptions note blackened or
darkened, olivaceous stromata. The definitive work by Petch (1921b) contains beautiful
watercolour plates, often depicting stromata with a carbonaceous appearance. Even
today, these plates are regarded as 'technically accurate', although extensive collection
and isolation work in Thailand indicate that blackening is associated with dried
herbarium material or, when recorded in the field, is due to hyperparasitism of the
entomopathogen.
Perithecia are either completely immersed (Fig. 2.1.1) or are superficial and covered
only by a thin mycelium; typically globose, flask-shaped or pyriform. Asci have a
thickened apical cap with a narrow thread-like pore; ascospores filiform, multiseptate,
whole or separating into part-spores (Figs 2.1.2,A; 2.1.3,A). The anamorph,
Aschersonia, may be found in the same stroma as the teleomorph or it may occur
separately on the host. Aschersonia is in the Coelomycetes of the Deuteromycotina and
the fruiting body consists of sunken pycnidia lined with conidiophores which produce
conidia (Figs 2.1.2,B; 2.1.3,B). Two groups of Aschersonia are recognised depending
on whether they produce paraphyses (sterile hairs) in the pycnidium or not.
noitceS 1.2 ,secnerefer .p 22
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Fig. 2.1.1. Macrofeatures of a aUercopyH ainosrehcsA- sp. A - The sexual stage (teleomorph) of the
aUercopyH is on the let~ and the dark necks of the perithecia are clearly visible. The asexual stage (anamorph)
of the ainosrehcsA is on the right and the fructifications (pycnidia) open onto the surface (arrow). B - Section
through a "cushion" (stroma) on the mummified body of a scale insect (short arrow). ehT aUercopyH
perithecia are in the upper portion (long arrows) overgrowing the ainosrehcsA stage.
In his extensive review of the genus Hypocrella and its anamorph Aschersonia, Petch
(1921b) noted that, in the 75 years since their discovery, some 60 species of Aschersonia
had been described and about 70 species of Hypocrella. Material was often sent to
different workers around the world and, because of poor communication, many