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Entomopathogenic fungi as biocontrol agents

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  • 29.09
  • Kunming Institute of Botany, CAS Kunming Yunnan China

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An attractive alternative method to chemical pesticides is the microbial biocontrol (MBCAs) agents. They are the natural enemies devastating the pest population with no hazard effects on human health and the environment. Entomopathogenic fungi has an important position among all the biocontrol agents because of its route of pathogenicity, broad host rang and its ability to control both sap sucking pests such as mosquitoes and aphids as well as pests with chewing mouthparts, yet they only cover a small percentage of the total insecticide market. Improvements are needed to fulfill the requirements for high market share. Entomopathogenic fungi differ from other microorganisms in their infection process: they directly breach the cuticle to enter the insect hemocoel, while other microorganisms enter by ingestion through mouth and then cause disease. Insect cuticle is mainly composed of chitin and protein surrounded by wax, lipid layer or fatty acids. Fungal pathogenesis mainly starts with the secretion of cuticle degrading enzymes. Some important and well known cuticle degrading enzymes are chitinase, protease and lipase which can degrade chitin, protein and lipid of the cuticle, respectively. In this review we collected literatures from different sources and we arranged them in a such a way to better to understand the process of insect pathogenicity of entomopathogenic fungi and to find ways to improve the virulence of wild strain fungi to shorten the killing time of the pest and to commercialize the entomopathogenic fungi. In this way, the market share of the fungal entomopathogenic fungi will increase and a decrease in the usage of synthetic chemical pesticides will automatically follow.
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Research Report Open Access
Entomopathogenic Fungi as Microbial Biocontrol Agent
Sehroon Khan , Lihua Guo , Yushanjiang Maimaiti , Mahmut Mijit , Dewen Qiu
Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences
(CAAS), Beijing, P.R. China
Corresponding authors email: qiudewen@caas.net.cn; Authors
Molecular Plant Breeding, 2012, Vol.3, No.7 doi: 10.5376/mpb.2012.03.0007
Received: 25 Apr., 2012
Accepted: 11 May, 2012
Published: 20 May, 2012
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Khan et al., 2012, Entomopathogenic Fungi as Microbial Biocontrol Agent, Molecular Plant Breeding, Vol.3, No.7 63-79 (doi: 10.5376/mpb.2012.03.0007)
Abstract An attractive alternative method to chemical pesticides is the microbial biocontrol (MBCAs) agents. They are the natural
enemies devastating the pest population with no hazard effects on human health and the environment. Entomopathogenic fungi has
an important position among all the biocontrol agents because of its route of pathogenicity, broad host rang and its ability to control
both sap sucking pests such as mosquitoes and aphids as well as pests with chewing mouthparts, yet they only cover a small
percentage of the total insecticide market. Improvements are needed to fulfill the requirements for high market share.
Entomopathogenic fungi differ from other microorganisms in their infection process: they directly breach the cuticle to enter the
insect hemocoel, while other microorganisms enter by ingestion through mouth and then cause disease. Insect cuticle is mainly
composed of chitin and protein surrounded by wax, lipid layer or fatty acids. Fungal pathogenesis mainly starts with the secretion of
cuticle degrading enzymes. Some important and well known cuticle degrading enzymes are chitinase, protease and lipase which can
degrade chitin, protein and lipid of the cuticle, respectively. In this review we collected literatures from different sources and we
arranged them in a such a way to better to understand the process of insect pathogenicity of entomopathogenic fungi and to find ways
to improve the virulence of wild strain fungi to shorten the killing time of the pest and to commercialize the entomopathogenic fungi.
In this way, the market share of the fungal entomopathogenic fungi will increase and a decrease in the usage of synthetic chemical
pesticides will automatically follow.
Keywords Entomopathogenic fungi; Beauveria bassiana; Biocontrol agents; Enzymes; Pathogenesis
Background
Integrated Pest Management (IPM) involves ins-
pection, identification and treatment of pests. The
treatment (when required) is carried out after inspection
and identification with an environmentally safe and
pest specific pesticide with limited persistence. Therefore
biological pest management is considered as an
important part of IPM. Biological control is an
important part of integrated pest management (IPM).
According to Oerke and Dehne (2004), insect pests
are responsible for an estimated 42% of all losses in
crop production. Extensive use of synthetic chemical
pesticides, insecticide resistance to chemical pesticides
(Ffrench-Constant et al., 2004), the resulting environ-
mental pollution, adverse effects on human health and
other organisms and the demand for reduced chemical
inputs in agriculture have provided an impetus to the
development of alternative forms of pest control
(Wilson and Tisdall, 2001). An attractive alternative
method to chemical pesticides is biocontrol (Nicholson,
2007) and the microbial biocontrol (MBCAs) agents
as the natural enemies of the pest population devastate
pests with no hazard effects on human health and
environment. As the microbial biocontrol agents have
complex mode of action, it’s very difficult for a pest to
develop resistance against MBCAs. The present
MBCAs are viruses, bacteria, nematodes, and fungi
and they are used throughout the world with great
advantage and success. But fungal biocontrol agents
are the most important among all the MBCAs due to
easy delivery, improving formulation, vast number of
pathogenic strains known, easy engineering techniques
and over-expression of endogenous proteins or exo-
genous toxins (St. Leger et al., 1996; Butt et al., 2001;
Wang and St. Leger, 2007; Federici et al., 2008; St.
Leger and Wang, 2010). Similarly, the entomopathogenic
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fungi are important among all the biological control
agents due to its broad host range, route of
pathogenicity and its ability to control sap sucking
pests such as mosquitoes and aphids (Butt, 2002; Qazi
and Khachatourians, 2005; Thomas and Read, 2007;
Fan et al., 2007) as well as pests with chewing
mouthparts (Hajek and St. Leger, 1994; de Faria and
Wraight, 2007).
This review will help us understand entomopatho-
genic fungal virulence and present the most recent
improvements and achievements in the relevant field.
This will help us determine how to improve the
virulence of entomopathogenic fungi to shorten the
killing time of pest.
1 Entomopathogenic Fungi (EPF)
Entomopathogenic fungi (EPF) are widely distributed
with both restricted and wide host ranges which have
different biocontrol potentials against arthropods
insects and plant pathogenic fungi. Entomopathogenic
fungi were among the first organisms to be used for
the biological control of pests. More than 700 species
of fungi from around 90 genera are pathogenic to
insects (Khachatourians and Sohail, 2008). Most EPF
species are from the fungal divisions Ascomycota and
Zygomycota. The ascomycete fungi were previously
divided into two groups, the Ascomycota and the
Deuteromycota (Table 1). The Fungi Imperfecti of
Deuteromycota was known for having no sexual stage
was known called as. But later on, cultural and
molecular studies have demonstrated that some of
these ―imperfect fungi‖ (formally class Hyphomycetes
in the Deuteromycota) were in fact anamorphs (asexual
forms) of the Ascomycota within the order Hypocreales,
and Clavicipitaceae family (Fukatzu, 1997; Hodge,
2003; Krasnoff, 1995; Shimazu, 1998). Within the
Zygomycota, the most entomopathogenic species are
in the order Entomophthorales (Roy et al., 2006).
These fungi nutritionally may be saprotrophs that
colonize the rhizosphere and phyllosphere, endophytic
saprotrophs, hemibiotrophic, necrotrophic of plants,
entomopathogenic or mycoparasitic and some of them
have adopted more than one econutritional mode.
2 Life cycle of entomopathogenic fungi
The life cycle of EPF is composed of the spore which
geminates into mycelia and the mycelia in turnproduce
spores (sporemyceliaspore phases). The life cycle
of most entomopathogenic fungi consist of two phases:
a normal mycelia growth phase mostly outside the
host body and a yeast like budding phase mostly in the
hemocoel of host. The yeast-like, dimorphic mode of
growth in Beauveria bassiana was described by Alves
et al (2002); and the production of oblong blastospore-
like propagules in M. flavoviride was described by
Fargues et al (2002). The life cycle of M. anisopliae
under liquid culture conditions has also been
described (Uribe and Khachatourians, 2008).
Table 1 Classification of entomopathogenic fungi (Roy et al., 2006)
Division
Class
Order
Family
Genus
Zygomycota
Zygomycetes
Entomophthorales
Entomophthoraceae
Entomophaga
Entomophthora
Erynia
Eryniopsis
Furia
Massospora
Strongwellsea
Pandora
Tarichium
Zoophthora
Neozygitaceae
Neozygites
Ascomycota
Sordariomycetes
Hypocreales
Clavicipitaceae
Beauveriaa
Cordyceps
Cordycepioideus
Lecanicilliuma
Metarhiziuma
Nomuraea
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Beauveria bassiana in the absence of a specific insect
host grows through an asexual vegetative life cycle
consists of germination, filamentous growth and
formation of sympoduloconidia (Figure 1B). In the
presence of its host insect, Beauveria conidiospores
germinate on the surface of the cuticle of host and
penetrate the insect’s integument through the
germinated hyphal tubes where the fungus alters its
growth morphology to a yeast-like phase and produces
hyphal bodies by budding like growth, which circulate
in the haemolymph (Figure 1A) resulting in the host
death. The fungal growth then reverts back to the
typical hyphal form (the saprotrophic stage). The
ability to convert to the yeast-like phase may be a
prerequisite for pathogenicity.
Figure 1 Entomopathogenic dimorphic mode of growth
Note: A: Yeast-like parasitic phase during infection of suscep-
tible species; B: Saprobic phase shows filamentous hyphae
Entomopathogenic fungi, Verticillium lecanii, Beauveria
bassiana and Metarhizium anisopliae are intensively
studied as common natural enemies and important
epizootics of aphids and other agricultural pests
(Roberts and St. Leger, 2004; Thomas and Read, 2007;
Wang et al., 2004; Milner, 1997; Li and Sheng, 2007).
Beauveria bassiana (Balsamo) Vuilemin is one of the
major fungal entomopathogens infecting nearly 95%
of migratory alate aphids, especially M. persicae
(Chen et al., 2008). Beauveria bassiana and Verticillium
lecanii have dual biological control properties, i.e.
they are natural enemies of pests and also plant
pathogens (Bonnie et al., 2010; Goettel et al., 2008).
Koppert Biological Systems currently use Verticillium
lecanii (Zimm. Viegas) as an insect pathogen which
has been commercialized for controlling aphids (Faria
and Wraight, 2007) and it is effective in controlling
plant pathogenic fungi like powdery mildews (Askary
et al., 1998; Dik et al., 1998; Miller et al., 2004), rusts
(Spencer and Atkey, 1981), green molds (Benhamou
and Brodeur, 2000), Fusarium (Koike et al., 2007),
Verticillium dahliae (Kusunoki et al., 2006) and
Pythium ultimum (Benhamou and Brodeur, 2001).
Beauveria bassiana is reported to limit the growth of
plant pathogenic fungi in vitro, colonize endophytically
in numerous plants and induce systemic resistance
when pathogen infect the plant as well as reducing the
diseases caused by soil born plant pathogens like
Pythium, Rhizoctonia, and Fusarium (Ownley et al.,
2010). Mitosporic fungi are generally environmentally
friendly with negligible or low mammalian toxicity,
have no residual toxicity (Copping, 2004) and are
successful as mycoinsecticides against aphids (Faria
and Wraight, 2007; Milner, 1997; Shah and Pell, 2003).
To date, several mycopesticides have been developed
and used in several countries including the United
Kingdom and the United States (Table 2) (Goettel et
al., 2005; Kiss, 2003). These include Vertalec® based
on Lecanicillium longisporum (Petch) Zare & Gams
(formerly known as Verticillium lecanii (Zimm.) Viegas)
against aphids, Botanigard® based on Beauveria
bassiana (Bals.) Vuill. against aphids and whitefly;
however, they remain a small percentage of the total
insecticides. The major reason for the small market
share of these fungi as mycoinsecticides is its slow
killing rate and an increase in market share is directly
proportional to killing speed (St Leger and Wang, 2009).
Although these products have the advantage of a
restricted host range, this specificity is also one of the
limiting factors for their commercial use (Ownley et
al., 2004). Therefore, a mycopesticide with a wider
host range but with little to no influence on other
natural enemies of pests or beneficial organisms may
have a commercial advantage if it simultaneously
controls various pests and/or plant diseases (Wraight
and Carruthers, 1999).
Insect pathogenic fungi are different in pathogenicity
than bacteria and viruses in that they infect insects by
breaching the host cuticle. The cuticle is composed of
chitin fibrils embedded in a matrix of proteins, lipids,
pigments and N-acylcatecholamines (Richard et al.,
2010). They secrete extracellular enzymes proteases,
chitinases and lipases to degrade the major constituents
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Table 2 Entomopathogenic fungi produced commercially and experimentally (Butt et al., 2001; Wraight et al., 2001; Copping, 2004;
Kabaluk and Gazdik, 2005; Zimmermann, 2007; Khachatourians, 1986)
Fungus
Product/Trade name
Company/Producer
Target pests
Culicinomyces
clavisporus
Mosquito larvae
Hirsutella thompsonii
Mycar
Citrus rust mite
Metarhizium
anisopliae
Meta-Sin®
Spittle bug; Sugarcane frog
hopper
Nomuraea rileyi
Lepidopteran larvae
Verticillium lecanii
Vertalec
Aphids; Coffee green bug;
Greenhouse whitefly thrips
Beauveria bassiana
Bio-Power
Stanes
Mite; Coffee green bug
BotaniGard ES; Botani-
Gard 22WP
Laverlam International (formerly
Emerald BioAgriculture)
Boverol
Fytovita
Conidia
LST
Mycotrol ES; Myco-
trol-O
Laverlam International (formerly
Emerald BioAgriculture)
Naturalis
Intrachem
Aphids Spittle bug; Sugar-
cane
Naturalis-L Andermatt
Biocontrol
Troy Biosciences Inc
Ostrinil
Arysta (formerly NPP, Calliope)
Proecol
Probioagro
Racer BB
SOM Phytopharma
Trichobass-L;
Trichobass-P
AMC Chemical/Trichodex
B. brongniartii (_B.
tenella)
Beauveria Schweizer
Lbu (formerly Eric Schweizer
Seeds)
Greenhouse whitefly thrips
Mosquito larvae
Betel
Arysta (formerly NPP, Calliope)
Biolisa-Kamikiri
Nitto Denko
Engerlingspilz
Andermatt Biocontrol AG
Melocont-Pilzgerste
Agrifutur-Kwizda
of the cuticle (i.e. protein, chitin and lipids) and allow
hyphal penetration (Wang et al., 2005; Cho et al.,
2006). Extracellular lipases are also involved in
microbial virulence and play different roles in the
infection process (Stehr et al., 2003). The success-
fulness of infection was directly proportional to
secretion of exoenzymes (Khachatourians, 1996). It is
believed that both mechanical force and enzymatic
action are involved in the penetration of fungus to the
hemocoel of the insect. In this review, we take an
overview of the chitinase, protease and lipase with
their importance in the process of pathogenesis.
Besides exoenzymes, the entomopathogenic fungi are
reported to secrete toxin proteins and metabolites in
vitro and sometime in vivo as well. There are a
number of toxic compounds in the filtrate of entomo-
pathogenic fungi such as small secondary metabolites,
cyclic peptides and macromolecular proteins. Beauveria
bassiana is reported to produce low molecular
weight cyclic peptides and Cyclosporins A and C with
insecticidal properties such as beauvericin, enniatins,
bassianolide, (Roberts, 1981; Vey et al., 2001), Oos-
porein (a red-colored dibenzoquinone with antibiotic
activity against gram-positive bacteria), andcyclic
peptides with immunosuppressive activities. There are
also some insecticidal cyclic peptides like beauvericin
and bassianolide isolated from Beauveria bassiana.
Some of the strains of Beauveria bassiana are reported
to produce high molecular weight compounds with
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toxic activity against pest, like hirsutellin A (Enrique
and Alain, 2004). However, the major obstacle
limiting the market share of these fungi as mycoin-
secticides is their slow killing speed and increase in
market share is directly proportional to killing speed
(St Leger and Wang, 2009).
A large number of studies were conducted to
potentiate and improve the virulence of entomopatho-
genic fungi to a greater extent than their individual
activities and thus increasing the market share. The
extensive transcriptomic and genetic study of entomo-
pathogenic fungal infection process revealed that a
number of different genes were involved in the
pathogenicity (Freimoser et al., 2003; Wang et al.,
2005; Cho et al., 2006a, 2006b, 2007) such as
chitinases (Bagga et al., 2004; Fang et al., 2005),
guanine nucleotide-binding proteins and its regulator
(Fang et al., 2007, 2008), adhesin which helps in
attachment of spore (Wang and St. Leger, 2007a), a
perilipin-like protein that regulates appressorium
turgor pressure and differentiation (Wang and St.
Leger, 2007b) and a cell protective coat protein
helping in escaping the pathogen from the host
immunity recognition (Wang and St. Leger, 2006).
Similarly, an increased virulence of the entomopatho-
genic fungi was observed with over-expression of
virulence genes such as subtilisin protease PR1A (St.
Leger et al., 1996), subtilisin protease PII gene
(Ahman et al., 2002), and hybrid chitinase containing
a chitin binding domain (Fan et al., 2007). Wang
and St. Leger (2007c) modified scorpion neurotoxin
peptide, AAIT using Metarhizium’s codon preferences
under the control of mc11 gene promoter for fungal
transformation. The LC50 of the transgenic strain
AaIT-Ma549 was reduced 22-fold against the Manduca
sexta and nine fold against the Aedes aegypti (Wang
and St. Leger, 2007c). AaIT-Ma549 was also tested
against the coleopteran coffee pest, Hypothenemus
hampei, reducing LC50 by 15.7-fold and the average
survival time by 20% (Pava-Ripoll et al., 2008).
3 Beauveria bassiana (Clavicipitaceae)
The entomopathogenic mitosporic ascomycete, Beau-
veria bassiana (Bals.) Vuill. is an important natural
pathogen of insects and it has been developed as a
microbial insecticide for use against many major
arthropod pests in agricultural, urban, forest, livestock
and aquatic environments (Charnley and Collins, 2007;
Faria and Wraight, 2007). It has been developed as a
microbial insecticide for use against many major
pests, including lepidopterans and orthopterans. About
33.9% of the mycoinsecticides is based on B. bassiana,
followed by Metarhizium anisopliae (33.9%), Isaria
fumosorosea (5.8%) and Beauveria brongniartii (4.1%)
(Faria and Wraight, 2007); however, to increase the
market share of B. bassiana, the killing speed which is
the major hindrance limiting their use as mycoinsec-
ticides should be accelerated, (St Leger and Wang,
2009). As natural strains of these fungi often lack
sufficient virulence or tolerance to adversity (Braga et
al., 2001a, 2001b; Ying and Feng, 2004; Rangel et al.,
2005), genetic manipulation is necessary to improve
their efficacy and ecological fitness (Roberts and St.
Leger, 2004; Fang et al., 2005). The importance of
the B. bassiana and B. brongniartii can be briefly
understood from table 3 below.
Research studies are carried out to optimize the
preparation and application of fungal inoculums
(Wraight et al., 2001) and (St Leger and Wang, 2009)
to improve the virulence of mycoinsecticides by
genetic modification. Based on this approach, most
studies on the virulence factors of entomopathogenic
fungi have been directed to elucidate the most relevant
cuticle degrading enzymes (Griesch and Vilcinskas,
1998; Khachatourians, 1996; St Leger et al., 1996),
because their over-expression in engineered strains
results in more fungi that are more deadly toward
insects (Fang et al., 2005; St Leger et al., 1996).
Similarly, over-expression of a chitinase gene (Bbchit1)
was found to enhance the virulence of Beauveria
bassiana against aphids (Myzus persicae) (Fang et
al., 2005). Importantly, different genes involved in
pathogenicity have been characterized from M.
anisopliae or B. bassiana and some of these genes
include cuticle degrading enzymes (Bagga et al., 2004;
Fang et al., 2005), G protein and its regulator (Fang et
al., 2007), adhesin that mediates spore attachment and
fungal differentiation (Wang and St. Leger, 2007a), a
perilipin-like protein that regulates appressorium
turgor pressure and differentiation (Wang and St.
Leger, 2007b), and a cell protective coat protein
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Table 3 Examples of effects of B. bassiana and B. brongniartii (strains and formulations) on beneficial and non-target organisms (this
table was taken from Zimmermann, 2007)
Beneficial organism
Fungus (Strain/Formu-
lation)
Lab./Field
Trials (L/F)
Results/Observations
References
Amblyseius cucumeris
B. bassiana (Naturalis-
L, BotaniGard WP)
L/F
No detrimental effect when sprayed onto
excised cucumber leaves
Jacobson et al.,
2001
Aphidius colemani; Orius
insidiosus; Phytoseiulus
Persimilis Encarsia formosa
B. bassiana (commercial
formulation, strain
JW-1)
L
Highly susceptible under laboratory condi-
tions, lower infection rates in greenhouse
Ludwig and
Oetting, 2001
Apis mellifera
B. bassiana
F
Conidia were applied in bee hives: low
mortality and no noticeable effect on
behavior, larvae and colony characteristics
Alves et al., 1996
Apis mellifera
B. bassiana (unformu-
lated Spore preparation)
L
B. bassiana reduced bee longevity at the
two highest concentrations tested and
caused mycosis at 106-108 spores per bee
Vandenberg,
1990
Apis mellifera
B. bassiana (Naturalis-
L, Bio-Power)
L
30-day dietary and contact studies had no
significant effect; LC50 (23 days, ingestion)
9 285 µg/bee
Copping, 2004
Apis mellifera
B. brongniartii
F
No negative effects noticed
Wallner, 1988
Arthropod and nematode
populations
B. bassiana (Naturalis-
L)
F
Chlorpyrifos had a stronger negative
impact than the microbial treatment
Wang et al., 2001
Bembidion lampros; Agonum
dorsale
B. bassiana
F/L
A negligible number was infected; low
susceptibility of both species
Riedel and Steen-
berg, 1998
Bombus terrestris
B. bassiana
L/F
Able to infect bumblebees; it appears that
there are no risks if the fungus is
incorporated into soil or sprayed onto
plants that are not attractive to bumblebees
Hokkanen et al.,
2003
Carabidae; Calanthus
micropterus; Calanthus
piceus; Carabus violaceus;
Cychrus caraboides; Leistus
ruefescens; Nebria
brevicollis; Pterostichus
oblongopunctatus; P. niger
B. bassiana
L
No adverse effects noticed
Hicks et al., 2001
Carabidae; Staphylinidae
B. bassiana
F
Infection levels in adult ground beetles and
rove beetles were low (Carabidae max.
7.6% and Staphylinidae max. 7.0%); an
epizootic in the staphylinid Anotylus
rugosus (67%) and Gyrohypnus angustatus
(37%) was observed
Steenberg et al.,
1995
Cephalonomia tarsalis
B. bassiana
F
3 h exposure to 100 and 500 mg/kg wheat
resulted in 52.5 and 68.6% mortality
Lord, 2001
Chrysoperla carnea
B. bassiana
L
Temperature, starvation and nutrition
stresses significantly affected the
susceptibility; nutrition stress caused the
most increase in adult and larval mortality
Donegan and
Lighthart, 1989
Coleomegilla maculate
B. bassiana (isolate
ARSEF 3113)
L/F
No mortality was observed
Pingel and
Lewis, 1996
Coleomegilla maculate
Eriopis connexa
B. bassiana (isolate
ARSEF 731)
Mortality after direct application of spores;
exposure via sprayed leaf surfaces resulted
in no infection
Magalhaes et al.,
1988
Coleomegilla maculate
B. bassiana (10 isolates)
L
6 isolates were highly virulent, 3 isolates
caused low mortality
Todorova et al.,
2000
Diadegma semiclausum
B. bassiana
L
Detrimental effects on cocoon production
and emergence depending on concentration
Furlong, 2004
Formica polyctena
B. brongniartii
F
No negative effects noticed
Dombrow, 1988
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Continuing table 3
Beneficial organism
Fungus (Strain/Formu-
lation)
Lab./Field
Trials (L/F)
Results/Observations
References
Earthworms: Lumbricus
terrestris and others
B. brongniartii (com-
mercial product of
barley grains)
L/F
No effect in lab and in field noticed
Hozzank et al.,
2003
Earthworms: Lumbricus
terrestris
B. brongniartii
L
No effect on earth worms noticed
Arregger-
Zavadil, 1992
Earthworms: Aporrectodea
caliginosa
B. bassiana (Bb64)
L
No effect on hatching rate of cocoons
Nuutinen et al.,
1991
Lysiphlebus testaceipe
Aphidius colmani
B. bassiana
F
No significant impacts on both parasitoids
Murphy et al.,
1999
Megachile rotundata
B. bassiana (strain for
grasshopper control)
L
Spray-application of flowering alfalfa in
pots: female and male mortality averaged
9%; no difference in treatment and control;
however B. bassiana grew out from dead
bees
Goettel and
Johnson, 1992
Nontarget arthropods
(forests)
B. brongniartii
F
Only 1.1% of 10 165 collected insects and
spiders were infected
Baltensweiler
and Cerutti, 1986
Nontarget arthropods
(forests)
B. brongniartii
F
1 671 nontarget specimens were collected:
3.4% of them were infected, mainly species
from Araneae, Thysanoptera, Homoptera,
Coleoptera and Lepidoptera
Back et al., 1988
Nontarget arthropods (major
predators, parasitoids and
pollinators on rangeland)
B. bassiana (strain
GHA)
F
No statistical differences in the abundance
of aerial insects
Brinkman and
Fuller, 1999
Nontarget arthropods
(forests)
B. bassiana (emulsi-
fiable concentrate)
F
From 3 615 invertebrates collected, only
2.8% became infected; B. bassiana could
be applied to forest soil without a
significant negative impact on forest-
dwelling invertebrate population
Parker et al.,
1997
Non-target beetle
communities
B. bassiana (strain SP
16)
F
No detectable effects
Ivie et al., 2002
Perillus bioculatus
B. bassiana (six
isolates)
L
5 isolates were highly pathogenic, isolate
IPP46 showed low pathogenicity
Todorova et al.,
2002
Pimelia senegalensis,
Trachyderma hispida, Bracon
hebetor, Apoanagyrus lopezi
B. bassiana
L
No infection in P. senegalensis and T.
hispida ; 100% mortality in the parasitoids
B. hebetor and A. lopezi
Danfa et al.,
1999
Poecilus versicolor
B. brongniartii
(Melocont-Pilzgerste,
Melocont-WP, and
Melocont-WG)
L
No significant negative effects on P.
versicolor could be observed
Traugott et al.,
2005
Predatory mites: O. insidiosus,
A. colemani, Dacnusa sibiria,
Parasites: Encarsia Formosa,
Eretmocerus Eremicus,
Aphidoletes aphidimyza
B. bassiana (Botanigard
ES)
F
Can be used, not recommended during
application of B. bassiana used with
caution during application of B. bassiana
Shipp et al., 2003
Prorops nasuta
B. bassiana (3 isolates)
L
Strain 25 caused the lowest infection level
De La Rosa et
al., 2000
Serangium parcesetosum
B. bassiana
L
The predator had significantly lower
survivorship when sprayed with B.
bassiana than with P. fumosoroseus;
feeding on B. bassiana contaminated prey
caused 86% mortality
Poprawski et al.,
1998
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70
involved in evading host immune responses (Wang
and St. Leger, 2006).
4 Entomopathogenic fungal virulence enzymes
The initial interaction in the pathogenesis is mediated
by mechanical force, enzymatic processes and perhaps
certain metabolic acids. The enzymes responsible for
successful interaction with the host and environment
are listed in Table 4 (Khachatourians and Qazi, 2008).
The enzymes involved in pathogenesis of insects are
generally grouped in to proteases and peptidases,
chitinases and lipases.
4.1 Proteases and peptidases
Insect cuticle mainly is composed of chitin and
protein; hence proteases and peptidases of EPF are
important for the degradation of the insect cuticle,
saprophytic growth of the fungi, activation of the
prophenol oxidase in the hemolymph, and they act as
virulence factor. The fungi from which protein degra-
ding enzymes proteases, collagenases, and chymolea-
stases have been identified and characterized are A.
aleyrodis, B. bassiana, B. brongniartii, E. coronata,
Erynia spp., Lagenidium giganteum, Nomuraea rileyi,
M. anisopliae and V. lecanii (Charnley and St Leger
1991; Khachatourians, 1991, 1996; Sheng et al., 2006).
Joshi et al., (1995) cloned extracellular subtilisin-like
serine endoprotease (Pr1) from B. bassiana and
subtilisin-like protease (Pr1B) (Joshi et al., 1997) with
54% sequence homology to Pr1A. Screen and St Leger
(2000) found chymotrypsin (CHY1) of 374 amino acids
with pI of 5.07 and MW38279 from M. anisopliae.
Similarly, Freimoser et al (2005) identified some
overlapped gene responses with unique expression
patterns in response to cuticles from Lymantria dispar,
Blaberus giganteus and Popilla japonica and measured
gene expression responses to a number of insect
cuticles by using cDNA microarrays constructed from
an expressed sequence tags (EST) clone collection of
837 genes.
Small and Bidochka (2005) identified the sequence of
seven conidiation associated genes (cag) using
subtractive hybridization in M. anisopliae. Out of
which, cag7 was found to be essential for cuticle
degradation having encoded an extracellular
subtilisin-like proteinase (Pr1). Kim et al (1999)
described the gene structure and expression of a novel
B. bassiana protease (bassianin I) which is 1 137 bp
and 379 amino acids long. Bidochka and Melzer
(2000) reported genetic polymorphisms in three
Table 4 Entomopathogenic fungal protein encoding genes isolated and sequenced (Khachatourians and Qazi, 2008)
Fungus
Gene
Enzyme
References
Metarhizium anisopliae
sod
Superoxide dismutase
Shrank et al., 1993
Pr1B
Subtilisin like protease
Joshi et al., 1997
Pr1 (A-K)
Protease
Bagga et al., 2004
CRR1
DNA binding protein
Screen et al., 1997
nrr1
Nitrogen response regulator
Screen et al., 1998
chit1
Chitinase
Bogo et al., 1998
Chitinase
Kang et al., 1998
Chitin synthase
Nam et al., 1998
chi2
Chitinase
Baratto et al., 2003; 2006; Screen et al., 2001
MeCPAA
Zinc carboxypeptidase
Joshi and St Leger, 1999
ssgA
Hydrophobin
Bidochka et al., 2001
Trehalase
Zhao et al., 2006
Peptide synthetase
Bailey et al., 1996
trp1
Tryptophan synthetase
Staats et al., 2004
Beauveria bassiana
prt1
Protease
Joshi et al., 1995
Bassianin I
Kim et al., 1999
prt1-like
Serine endoprotease
Fang et al., 2002
chit
Chitinase
Fang et al., 2005
Endonuclease
Yokoyama et al., 2002
buv1
UV repair
Chelico et al., 2006
B. brongniartii
buv1
UV repair
Chelico et al., 2006
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71
subtilisin-like protease isoforms (Pr1A, Pr1B, Pr1C)
from isolates of M. anisopliae and an extracellular
protease from B. bassiana (BBP) has also been
purified and characterized by Urtiz and Rice (2000).
The isoelectric point of BBP was 7.5 and it is 0.5 kDa
smaller than Pr1. Fang et al (2002) reported a cuticle-
degrading protease (CDEP-1) from B. bassiana pre-
dicting a protein of 377 amino acids (Mr 38 616, pI
8.302) with 1 134 bp. Southern analysis indicated that
CDEP-1 is a single-copy gene. St Leger et al (1996)
constructed an engineered mycoinsecticides based on
M. anisopliae by over-expressing the toxic protease
Pr1 from M. anisopliae genome to accelerate the
killing speed of M. anisopliae. The over-expression of
Pr1 in the hemolymph of M. sexta activates the
phenoloxidase system which causes 25% reduction
in the time of death and 40% reduction in food
consumption.
4.2 Chitinases
The major component of insect cuticle is chitin,
therefore both endo and exo-chitinases play critical
roles in the cleavage of N-Acetylglucosamine (NAGA)
polymer of the insect cuticle into smaller units or
monomers. Khachatourians (1991) demonstrated that
the extracellular chitinases are virulence determinant
factors. Chitinolytic enzymes (N-acetyl-β-D-glucosa-
minidases and endochitinases were present in the
broth culture supplemented with insect cuticles from
M. anisopliae, M. flavoviride, and B. bassiana (St
Leger et al., 1996). The chitinase from M. anisopliae
consists of acidic (pI 4.8) proteins with molecular
masses 43.5 kDa and 45 kDa. The identified N-terminal
sequences of both bands were similar to an endochi-
tinase from Trichoderma harzianum. Valadares-Inglis
and Peberdy (1997) located chitinolytic enzymes in
enzymatically produced protoplasts and whole cells
(mycelia) of M. anisopliae. No significant induction
was observed from mycelia, yet protoplasts were
found to induce these enzymes significantly. The
majority of chitinolytic activity was cell-bound in both
whole cells and protoplast preparations, and the
activity was mainly located in the membrane fraction.
Kang et al (1998, 1999) reported a chitinase with
molecular mass of 60 kD from M. anisopliae grown in
a medium containing chitin as the sole carbon source
with an optimum pH of 5.0, which is different from
the chitinases values previously reported by St Leger
et al (1996) for endo-chitinases of 33.0, 43.5, and 45
kDa and exo-chitinases of 110 kDa. Screen et al (2001)
cloned the chitinase gene (Chit1) from M. anisopliae
sf. acridum ARSEF strain 324 and M. anisopliae sf.
anisopliae ARSEF strain 2575 (Chit1) using the pro-
moter of Aspergillus (gpd) for constitutive expression.
A 42 kD chitinase of M. anisopliae was expressed and
characterized in Escherichia coli by Baratto et al
(2003) using a bacteriophage T7- based promoter
expression vector. Baratto et al (2006) performed
transcriptional analysis of the chitinase chi2 gene of M.
anisopliae var. anisopliae and showed that it has 1
542 bp encoding for a deduced 419 amino acids.
Nahar et al (2004) reported that the extracellular
constitutive chitin deacetylase (CDA) secreted by M.
anisopliae converts chitin (a β-1, 4-linked N-acetyl-
glucosamine polymer) into its deacetylated form
chitosan (a glucosamine polymer). This CDA was not
inhibited by solubilized melanin.
Fang et al (2005) purified an endochitinase from
liquid cultures of B. bassiana supplemented with
chitin. Bbchit1 was 33 kD (pI 5.4) and the encoding
gene, Bbchit1, and its upstream regulatory sequences
were cloned based on N-terminal amino acid sequence.
Bbchit1 contains no introns and it is present as a
single copy in the B. bassiana genome. The amino
acid sequence of Bbchit1 is similar to that of the
endochitinase of Streptomyces avermitilis, S. coelicolor
and T. harzianum (Chit36Y), but not to EPFs that
reflect novel chitinases. Fang and co-worker (2005)
constructed a B. bassiana transformants (gpd-Bbchit1),
which overproduced Bbchit1 and had enhanced
virulence.
4.3 Lipases
Although the major bulk components of the insect
cuticle are protein and chitin, the outermost epicuticular
surface layer are made up of a complex mixture of
non-polar lipids. Epicuticular lipids play a role in
chemical communication events (Blomquist and Vogt,
2003), and in keeping the cuticular surface dry which
affects insecticide and chemicals penetration (Hadley,
1981; Blomquist et al., 1987; Juárez, 1994). They
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72
exhibit certain unique structural characteristics such as
relatively high molecular mass and chemical stability,
which is mainly due to specific physicochemical
properties such as length and branching of the carbon
chains (usually between 20 to more than 40 carbons),
as well as the position and the kind of functional
groups and double bonds. The most abundant
components are long chain HC, wax esters, fatty
alcohols and free or sterified fatty acids.
The insect epicuticle contains lipoproteins, fats, and
waxy layers which would be barriers to EPF without
the action of lipases and lipoxygenases, as some of
these structures have anti-fungal activities, and EFP
can’t use them as substrates (Khachatourians, 1996).
In addition, some chains of saturated fatty acids even
inhibit the growth of some EPF. Lord et al (2002)
showed a role for the lipoxygenase pathway through
eicosanoid-mediated cellular immune response to the
B. bassiana. James et al (2003) demonstrated that
conidial germination of B. bassiana and P. fumosoroseus
are affected by cuticular lipids and silverleaf whitefly
(B. argentifolii). The whitefly nymphs produce thick
coating of long-chain wax esters affecting spore
germination.
4.4 The function of phospholipases in cuticle
penetration
Since lipids represent major chemical constituents of
the insect cuticle, enzymes capable of hydrolyzing
these compounds, such as phospholipases, could be
expected to be involved in the cuticle disruption
processes that occur during host invasion. Phospho-
lipases are a heterogeneous group of enzymes that are
able to hydrolyze one or more ester linkages in
glycerophospholipids. The action of phospholipases
can result in the destabilization of membranes, cell
lysis and the release of lipid second messengers
(Ghannoum, 2000). These enzymes are categorized
according to the location of the ester link that is
cleaved (Figure 2). Although phospholipase B (PLB)
refers to an enzyme that can remove both sn-1 and
sn-2 fatty acids, this enzyme also has lysophospho-
lipase-transacylase activity.
Extracellular phospholipases have been implicated as
pathogenicity factors for bacteria, rickettsiae and
Figure 2 Sites of action of phospholipases
Note: A1, A2, B, C and D indicate cleavage sites of the corres-
ponding phospholipases (PLA1, PLA2, PLB, PLC and PLD)
protozoa. The type of phospholipase involved in
virulence varies with the organism. For example, C.
perfringens (Alape-Giron, 2000) secretes a phospholi-
pase C (PLC), whereas T. gondii secretes a phosphor-
lipase A (PLA). The importance of these enzymes,
especially PLB, for virulence has so far only been
verified in medically important fungi. PLB was
secreted by different clinically important fungal
species such as Candida albicans (Mukherjee, 2001),
Aspergillus fumigatus and Cryptococcus neoformans.
The role of PLB in the pathogenicity of entomopatho-
genic fungi remains to be determined, even in the
best-studied species M. anisopliae.
5 Advantages of using fungi as insecticides
The advantages of using fungi as insecticides are: (1)
They have high degree of specificity for controlling
pest without affecting beneficial insect predators and
non-harmful parasites. (2) They have no hazard effects
on environment or the health of mammals which is
normally affected by chemical insecticide applications.
(3) They have different ways of infection; hence insect
resistance cannot be developed and they can be used
as prolonged pest control. (4) They have genes for
secretion of insect toxins; hence they have high
potentials for further development by biotechnological
research. (5) Some of them have endophytic capability;
hence they can play important roles in the activation
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73
of immune system. (6) High persistence in the envi-
ronment provides long-term suppression effects of
entomopathogenic fungi on pest.
6 Disadvantages of the fungi as biocontrol
agents
(1) They have very slow killing rate: normally 2-3
weeks are required to kill the insects whereas
chemical insecticides may need only 2-3 hours. (2) As
the pathogenesis process of the fungi is bioprocess, it
requires specific conditions to be carried out, such as
specific temperature, humidity and period of light. (3)
They have high specificity in killing pests making
them a narrow host killer while a broad range killer
pesticide is required for commercialization, hence
additional control agents are needed for other pests. (4)
Their production is relatively expensive and the short
shelf life of spores necessitates cold storage. (5) The
persistence and efficacy of entomopathogenic fungi in
the host population vary in different insect species,
thus insect-specific application techniques need to be
optimized to retain long-term impacts. (6) They also
present potential risks to immunodepressive people.
Conclusion
Since centuries ago, fungi have always been used for
medicinal and other beneficial proposes and they are
just as important nowadays. In this review, we
summarized the advantages and applications of fungi
as a biopesticides, attempted and collected the know-
ledge about the entomopathogenic fungi as biocontrol
agents. We collected knowledge of the past and
present about entomopathogenic fungi to explore
ways to improve the abilities of entomopathogenic
fungi as a biocontrol agent. In this way, new ideas
and hypothesis will emerge which will farther help
developing the fungi’s capabilities as biocontrol
agents. New techniques will be developed which will
help manage the pest in a better way as the present
pathogenesis mechanism of fungi is slow and needs
improvement. Genetic and proteomic studies are
expected to be the main tools for the future develop-
ment of the entomopathogenic fungi as biocontrol
agents; however, in the near future, there will be
awider array of techniques become available to
biologists which will enable us to take full advantage
of entomopathogenic fungi.
Acknowledgements
This work was supported by International Cooperation Fund
(No. 2012DFR30810). We also acknowledge the China
Scholarship Council for the PhD scholarship.
References
Ahman J., Johansson T., Olsson M., Punt P.J., van den Hondel C.A., and
Tunlid A., 2002, Improving the pathogenicity of a nematodetrapping
fungus by genetic engineering of a subtilisin with nematotoxic activity,
Appl. Environ. Microbiol., 73: 295-302
Alape-Giron A., and Flores-Diaz M., 2000, Identification of residues critical
for toxicity in albicans restores virulence in vivo, Microbiology, 147:
2585-2597
Alves S.B., Marchini L.C., Pereira R.M., and Baumgratz L.L., 1996, Effects
of some insect pathogens on the africanized honey bee, Apis mellifera
L. (Hym., Apidae), Journal of Applied Entomology, 120: 559-564
http://dx.doi.org/10.1111/j.1439-0418.1996.tb01652.x
Alves S.B., Rossi L.S., Lopes R.B., Tamai M.A., and Pereira R.M., 2002,
Beauveria bassiana yeast phase on agar medium and its pathogenicity
against Diatraea saccharalis (Lepidoptera: Crambidae) and Tetranychus
urticae (Acari: Tetranychidae), J. Invert. Pathol., 81: 70-77 http://dx.
doi.org/10.1016/S0022-2011(02)00147-7
Arregger-Zavadil E., 1992, Grundlagen zur Autokologie und Artspezifitot
des Pilzes Beauveria brongniartii (Sacc.) Petch als Pathogen des
Maikafers (Melolontha melolontha L.), Ph.D. thesis, ETH-Zurich
University, Switzerland, pp.153
Askary H., Benhamou N., and Brodeur J., 1997, Ultrastructural and
cytochemical investigations of the antagonistic effect of Verticillium
lecanii on cucumber powdery mildew, Phytopath., 87: 359-368
http://dx.doi.org/10.1094/PHYTO.1997.87.3.359 PMid:18945181
Back H., Spreier B., Nahrig D., and Thielemann U., 1988, Auswirkungen
des Waldmaika ferbekamp fungsversuches im Forstbezirk Hardt 1987
auf die Arthropodenfauna. Mitteilungen der Forstlichen Versuchsund
Forschungsanstalt Baden-Wu rttemberg, Freiburg/B, 132: 141-154
Bagga S., Hu G., Screen S.E., and St Leger R.J., 2004, Reconstructing the
diversification of subtilisins in the pathogenic fungus Metarhizium
anisopliae, Gene, 324: 159-169 http://dx.doi.org/10.1016/j.gene.2003.
09.031 PMid:14693381
Bailey A.M., Kershaw M.J., Hunt B.A., Paterson I.C., Charnley A.K.,
Reynolds S.E., and Clarkson J.M., 1996, Cloning and sequence
analysis of an intron-containing domain from a peptide synthetase-
encoding gene of the entomopathogenic fungus Metarhizium anisopliae,
Gene, 173: 195-197 http://dx.doi.org/10.1016/0378-1119(96)00212-0
Baltensweiler W., and Cerutti F., 1986, Bericht uber die Nebenwirkungen
einer Bekampfung des Maikafers (Melolontha melolontha L.) mit dem
Pilz Beauveria brongniartii (Sacc.) Petch auf die Arthropodenfauna
des Waldrandes, Mitteilungen der Schweizerischen Entomologischen
Gesellschaft, 59: 267-274
Baratto C.M., Dutra V., Boldo J.T., Leiria L.B., Vainstein M.H., and
Schrank A., 2006, Isolation, characterization, and transcriptional
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
74
analysis of the chitinase chi2 gene (DQ011663) from the biocontrol
fungus Metarhizium anisopliae var. anisopliae, Curr, Microbiol., 53:
217-221 http://dx.doi.org/10.1007/s00284-006-0078-6 PMid:16874542
Baratto C.M., Silva M.V., da Santi L., Passaglia L., Schrank I.S., Vainstein
M.H., and Schrank A., 2003, Expression and characterization of the 42
kDa chitinase of the biocontrol fungus Metarhizium anisopliae in
Escherichia coli, Can. J. Microbiol., 49: 723-726 http://dx.doi.org/10.
1139/w03-085 PMid:14735222
Benhamo N., and Brodeur J., 2001, Pre-inoculation of RiT-DNA
transformed cucumber roots with the mycoparasite, Verticillium
lecanii, induces host defense reactions against Pythium ultimum
infection, Physiol. Mol. Plant Pathol., 58: 133-146 http://dx.doi.org/
10.1006/pmpp.2001.0322
Benhamou N., and Brodeur J., 2000, Evidence of antibiosis and induced
host defense reaction in the interaction between Verticillium lecanii
and Penicillium digitatum, the causal agent of green mold,
Phytopathology, 90: 932-943 http://dx.doi.org/10.1094/PHYTO.2000.
90.9.932 PMid:18944516
Bidochka M.J., Kamp A.M., Lavender T.M., Dekoning J., and De Croos
J.N.A., 2001, Habitat association in two genetic groups of the
insectpathogenic fungus Metarhizium anisopliae: Uncovering cryptic
species? Appl. Environ. Microbiol., 67: 1335-1342 http://dx.doi.org/10.
1128/AEM.67.3.1335-1342.2001 PMid:11229929 PMCid:92732
Bidochka M.J., Menzies F.V., and Kamp A.M., 2002, Genetic groups of the
insect-pathogenic fungus Beauveria bassiana are associated with
habitat and thermal growth preferences, Arch. Microbiol., 178:
531-537 http://dx.doi.org/10.1007/s00203-002-0490-7 PMid:12420176
Blomquist G.J., and Vogt R.G., 2003, Biosynthesis and detection of
pheromones and plant volatilesintroduction and overview, In:
Blomquist G.J., and Vogt R.G. (eds.), Insect Pheromone Biochemistry
and Molecular Biology, Elsevier Academic Press, London, pp.137-200
Blomquist G.J., Nelson D.R., and de Renobales M., 1987, Chemistry,
biochemistry and physiology of insect cuticular lipids, Arch. Insect
Biochem, Physiol., 6: 227-265 http://dx.doi.org/10.1002/arch.940060404
Bogo M.R., Rota C.A., Jr. Pinto H., Ocampos M., Correa C.T., Vainstein
M.H., and Schrank A., 1998, A chitinase encoding gene (chit1 gene)
from the entomopathogen Metarhizium anisopliae: isolation and
characterization of genomic and full-length cDNA, Curr Microbiol, 37:
221-225 http://dx.doi.org/10.1007/s002849900368 PMid:9732526
Bonnie H., Kimberly D., and Fernando E., 2009, Endophytic fungal
entomopathogens with activity against plant pathogens: ecology and
evolution, BioControl., 55: 113-128
Braga G.U., Flint S.D., Messias C.L., Anderson A.J., and Roberts D.W.,
2001a, Effects of UVB irradiance on conidia and germinants of the
entomopathogenic Hyphomycete Metarhizium anisopliae: a study of
reciprocity and recovery, Photochem Photobiol., 73: 140-146 http://
dx.doi.org/10.1562/0031-8655(2001)0730140EOUIOC2.0.CO2 http://
dx.doi.org/10.1562/0031-8655(2001)073<0140:EOUIOC>2.0.CO;2
Braga G.U., Flint S.D., Miller C.D., Anderson A.J., and Roberts D.W.,
2001b, Both solar UVA and UVB radiation impair conidial
culturability and delay germination in the entomopathogenic fungus
Metarhizium anisopliae, Photochem Photobiol., 74: 734-739 http://
dx.doi.org/10.1562/0031-8655(2001)074<0734:BSUAUR>2.0.CO;2
http://dx.doi.org/10.1562/0031-8655(2001)0740734BSUAUR2.0.CO2
Brinkman M.A., and Fuller B.W., 1999, Influence of Beauveria bassiana
strain GHA on nontarget rangeland arthropod populations,
Environmental Entomology, 28: 863-867
Butt T.M., 2002, Use of entomogenous fungi for the control of insect pests,
In: Esser K., and Bennett J.W. (eds.), Mycota, Springer, Berlin,
pp.111-134
Butt T.M., Jackson C., and Magan N., 2001, Introduction Fungal biological
bontrol agents: progress, problems and potential, In: Butt T.M.,
Jackson C., and Magan N. (eds.), Fungi as biocontrol agents: progress,
problems and potential, Wallingford, CAB International, pp.1-8
http://dx.doi.org/10.1079/9780851993560.0000 http://dx.doi.org/10.
1079/9780851993560.0001
Charnley A., and Collins S.A., 2007, Entomopathogenic fungi and their role
in pest control. In: Howard D.H., and Miller J.D. (eds.), The Mycota
IV: Environmental and Microbial Relationships, Springer-Verlag,
Berlin, Heidelberg, pp.159-187
Charnley A.K., and St. Leger R.J., 1991, The role of cuticle degrading
enzymes in fungal pathogenesis in insects. In: Cole G.T., and Hoch
H.C. (eds.), The fungal spore and disease initiation in plant and
animals, Plenum, New York, pp.267-286
Chelico L., Haughian J.L., and Khachatourians G.G., 2006, Nucleotide
excision repair and photoreactivation in the entomopathogenic fungi
Beauveria bassiana, B. brongniartii, B. nivea, Metarhizium anisopliae,
Paecilomyces farinosus, and Verticillium lecanii, J. Appl. Microbiol.,
100: 964-972 http://dx.doi.org/10.1111/j.1365-2672.2006.02844.x
PMid:16629997
Chen C., Li Z.Y., and Feng M.G., 2008, Occurrence of entomopathogenic
fungi in migratory alate aphids in Yunnan Province of China,
BioControl., 53: 317-326 http://dx.doi.org/10.1007/s10526-006-9063-z
Cho E.M., Boucias D., and Keyhani N.O., 2006, EST analysis of cDNA
libraries from the entomopathogenic fungus Beauveria (Cordyceps)
bassiana. II. Fungal cells sporulating on chitin and producing
oosporein, Microbio, 152: 2855-2864 http://dx.doi.org/10.1099/mic.
0.28845-0 PMid:16946279
Cho E.M., Kirkland B.H., Holder D.J., and Keyhani N.O., 2007, Phage
display cDNA cloning and expression analysis of hydrophobins from
the entomopathogenic fungus Beauveria (Cordyceps) bassiana,
Microbiology, 153: 3438-3447 http://dx.doi.org/10.1099/mic.0.2007/
008532-0 PMid:17906142
Cho E.M., Liu L., Farmerie W., and Keyhani N.O., 2006a, EST analysis of
cDNA libraries from the entomopathogenic fungus Beauveria
(Cordyceps) bassiana. I. Evidence for stage-specific gene expression
in aerial conidia, in vitro blastospores and submerged conidia,
Microbiology, 152: 2843-2854 http://dx.doi.org/10.1099/mic.0.28844-0
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
75
PMid:16946278
Cho E.M., Liu L., Farmerie W., and Keyhani N.O., 2006b, EST analysis of
cDNA libraries from the entomopathogenic fungus Beauveria
(Cordyceps) bassiana. I. Evidence for stage-specific gene expression
in aerial conidia, in vitro blastospores and submerged conidia,
Microbiology, 152: 2843-2854 http://dx.doi.org/10.1099/mic.0.28844-0
PMid:16946278
Copping L.G., 2004, The manual of biocontrol agents, british crop
protection council, crop protection, Crop Prot., 23: 275-285
Danfa A., and van der Valk H.C.H.G., 1999, Laboratory testing of
Metarhizium spp. and Beauveria bassiana on Sahelian non-target
arthropods, Biocontrol Science and Technology, 9: 187-198
http://dx.doi.org/10.1080/09583159929776
de Faria M.R., and Wraight S.P., 2007, Mycoinsecticides and
Mycoacaricides: a comprehensive list with worldwide coverage and
international classification of formulation types, Biol Control, 43:
237-256 http://dx.doi.org/10.1016/j.biocontrol.2007.08.001
de La Rosa W., Segura H.R., Barrera J.F., and Williams T., 2000, Laboratory
evaluation of the impact of entomopathogenic fungi on Prorops nasuta
(Hymenoptera: Bethylidae), a parasitoid of the coffe berry borer,
Environmental Entomology, 29: 126-131 http://dx.doi.org/10.1603/
0046-225X-29.1.126
Dik A.J., Verhaar M.A., and Be Langer R.R., 1998, Comparison of three
biological control agents against cucumber powdery mildew
(Sphaerotheca fuliginea) in semicommercial- scale glasshouse trials,
Eur. J. Plant Pathol., 104: 413-423 http://dx.doi.org/10.1023/A:10080-
25416672
Dombrow H., 1988, Auswirkungen des Versuchs zur Bekampfung des
Waldmaikafers 1987 im Forstbezirk Karlsruhe-Hardt auf Waldameisen.
Mitteilungen der Forstlichen Versuchs- und Forschungsanstalt
Baden-Wu rttemberg, Freiburg/B, 132: 165-171
Donegan K., and Lighthart B., 1989, Effect of several stress factors on the
susceptibility of the predatory insect, Chrysoperla carnea (Neuroptera:
Chrysopidae), to the fungal pathogen Beauveria bassiana, Journal of
Invertebrate Pathology, 54: 79-84 http://dx.doi.org/10.1016/0022-2011
(89)90143-2
Enrique Q., and Alain V.E.Y., 2004, Bassiacridin, a protein toxic for locusts
secreted by the entomopathogenic fungus Beauveria bassiana, Mycol.
Res., 108(4): 441-452 http://dx.doi.org/10.1017/S0953756204009724
PMid:15209284
Fan Y., Fang W., Guo S., Pei X., Zhang Y., Xiao Y., Li D., Jin K., Bidochka
M.J., and Pei Y., 2007, Increased insect virulence in Beauveria
bassiana strains overexpressing an engineered chitinase, Appl. Environ.
Microbiol., 73: 295-302 http://dx.doi.org/10.1128/AEM.0197406 PMid:
17085713 PMCid:1797141
Fang W., Leng B., Xiao Y., Jin K., Ma J., Fan Y., Feng J., Yang X., Zhang Y.,
and Pei Y., 2005, Cloning of Beauveria bassiana chitinase gene
Bbchit1 and its application to improve fungal strain virulence, Appl.
Environ. Microbiol., 71: 363-370 http://dx.doi.org/10.1128/AEM.71.1.
363-370.2005 PMid:15640210 PMCid:544255
Fang W., Pei Y., and Bidochka M.J., 2007, A regulator of a G protein
signalling (RGS) gene, cag8, from the insect-pathogenic fungus
Metarhizium anisopliae is involved in conidiation, virulence and
hydrophobin synthesis, Microbiology, 153: 1017-1025 http://dx.doi.
org/10.1099/mic.0.2006/002105-0 PMid:17379711
Fang W., Scully L.R., Zhang L., Pei Y., and Bidochka M.J., 2008,
Implication of a regulator of G protein signalling (BbRGS1) in
conidiation and conidial thermotolerance of the insect pathogenic
fungus Beauveria bassiana, FEMS Microbiol. Lett., 279: 146-156
http://dx.doi.org/10.1111/j.1574-6968.2007.00978.x PMid:18201190
Fargues J., Smiths N., Viial C., Vey A., Vega F., Mercadier G., and Quimby
P., 2002, Effect of liquid culture media on morphology, growth,
propagule production, and pathogenic activity of the hyphomycete,
Metarhizium flavoviride, Mycopathologia, 154: 127-138 http://dx.doi.
org/10.1023/A:1016068102003 PMid:12171445
Freimoser F.M., Hu G., and St Leger R.J., 2005, Variation in gene
expression patterns as the insect pathogen Metarhizium anisopliae
adapts to different host cuticles or nutrient deprivation in vitro,
Microbiology, 151: 361-371 http://dx.doi.org/10.1099/mic.0.27560-0
PMid:15699187
Fukatzu T., Sato H., and Kuriyama H., 1997, Isolation, inoculation to insect
host, and molecular phylogeny of an entomogenous fungus
Paecilomyces tenuipes, J. Invertebr. Pathol., 70: 203-208 http://dx.doi.
org/10.1006/jipa.1997.4696 PMid:9367727
Furlong M., 2004, Infection of the immature stages of Diadegma
semiclausum, an endolarval parasitoid of the diamondback moth, by
Beauveria bassiana, Journal of Invertebrate Pathology, 86: 52-55
http://dx.doi.org/10.1016/j.jip.2004.03.006 PMid:15145252
Ghannoum M.A., 2000, Potential role of phospholipases in virulence and
fungal pathogenesis, Clin. Microbiol. Rev., 13(1): 122 -143 http://dx.
doi.org/10.1128/CMR.13.1.122-143.2000 PMid:10627494 PMCid:
88936
Goettel M.S., Eilenberg J., and Glare T.R., 2005, Entomopathogenic fungi
and their role in regulation of insect populations, In: Gilbert L.I.,
Iatrou K., and Gill S. (eds.), Comprehensive Molecular Insect Science,
Elsevier, Amsterdam, Netherlands, pp.361-406 http://dx.doi.org/
10.1016/B0-44-451924-6/00088-0
Goettel M.S., Koike M., Kim J.J., Aiuchi D., Shinya R., and Brodeur J.,
2008, Potential of Lecanicillium spp. for management of insects,
nematodes and plant diseases, J. Invertebr. Pathol., 98: 256-261
http://dx.doi.org/10.1016/j.jip.2008.01.009 PMid:18423483
Griesch J., and Vilcinskas A., 1998, Proteases released by entomopathogenic
fungi impair phagocytic activity, attachment and spreading of
plasmatocytes isolated from hemolymph of the greater wax moth
Galleria mellonella, Biocontrol. Sci. Technol., 8: 517-531 http://dx.
doi.org/10.1080/09583159830036
Hadley N.F., 1981, Cuticular lipids of terrestrial plants and arthropods: a
comparison of their structure, composition and waterproofing barrier,
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
76
Biol. Rev., 56: 23-47 http://dx.doi.org/10.1111/j.1469-185X.1981.
tb00342.x
Hajek A.E., and St. Leger R.J., 1994, Interactions between fungal
athogenesis and insect hosts, Ann. Rev. Entomol., 39: 293-322
http://dx.doi.org/10.1146/annurev.en.39.010194.001453
Hicks B.J., Watt A.D., and Cosens D., 2001, The potential of Beauveria
bassiana (Hyphomycetes: Moniliales) as a biological control agent
against the pine beauty moth, Panolis flammea (Lepidoptera:
Noctuidae), Forest Ecology and Management, 149: 275-281
http://dx.doi.org/10.1016/S0378-1127(00)00561-2
Hodge K.T., 2003, Clavicipitaceous anamorphs, In: White J.F., Bacon C.W.,
Hywel-Jones N.L., and Spatafora J.W. (eds.), Clavicipitalean Fungi:
Evolutionary Biology, Chemistry, Biocontrol and Cultural Impacts,
Marcel Dekker, New York, pp.75-123 http://dx.doi.org/10.1201/
9780203912706.ch3
Hokkanen H.M.T., Zeng Q.Q., and Menzler-Hokkanen I., 2003, Assessing
the impacts of Metarhizium and Beauveria on bumblebees, In:
Hokkanen H.M.T., and Hajek A.E. (eds.), Environmental impacts of
microbial insecticides, Dordrecht, Kluwer Academic Publishers,
pp.63-71
Hozzank A., Keller S., Daniel O., and Schweizer C., 2003, Impact of
Beauveria brongniartii and Metarhizium anisopliae (Hyphomycetes)
on Lumbricus terrestris (Oligochaeta, Lumbricidae), IOBC/wprs
Bulletin, 26: 31-34
Ivie M.A., Pollock D.A., Gustafson D.I., Rasolomandimby J., Ivie L.L., and
Swearingen W.D., 2002, Field-based evaluation of biopesticide
impacts on native biodiversity: Malagasy coleopteran and anti-locust
entomopathogenic fungi, Journal of Economic Entomology, 95:
651-660 http://dx.doi.org/10.1603/0022-0493-95.4.651 PMid:12216803
Jacobson R.J., Chandler D., Fenlon J., and Russell K.M., 2001,
Compatibility of Beauveria bassiana (Balsamo) Vuillemin with
Amblyseius cucumeris Oudeman (Acarina: Phytoseiidae) to control
Frankliniella occidentalis Pergande (Thysanoptera: Thipidae) on
cucumber plants, Biocontrol Science and Technology, 11: 391-400
http://dx.doi.org/10.1080/09583150120055808
James R.R., Buckner J.S., and Freeman T.P., 2003, Cuticular lipids and
silverleaf whitefly stage affect conidial germination of Beauveria
bassiana and Paecilomyces fumosoroseus, J. Invert. Pathol., 84: 67-74
http://dx.doi.org/10.1016/j.jip.2003.08.006 PMid:14615214
Joshi L., and St Leger R.J., 1999, Cloning, expression, and substrate
specificity of MeCPA, a zinc carboxypeptidase that is secreted into
infected tissues by the fungal entomopathogen Metarhizium anisopliae,
J. Biol. Chem., 274: 9803-9811 http://dx.doi.org/10.1074/jbc.274.
14.9803 PMid:10092670
Joshi L., St Leger R.J., and Roberts D.W., 1997, Isolation of a cDNA
encoding a novel subtilisin-like protease (Pr1B) from the
entomopathogenic fungus, Metarhizium anisopliae using differential
display-RT-PCR, Gene, 197: 1-8 http://dx.doi.org/10.1016/S0378-1119
(97)00132-7
Joshi L., St. Leger R.J., and Bidochka M.J., 1995, Cloning of a
cuticledegrading protease from the entomopathogenic fungus, Beauveria
bassiana, FEMS Microbiol. Lett., 125: 211-217 http://dx.doi.org/10.
1111/j.1574-6968.1995.tb07360.x PMid:7875568
Juárez M.P., 1994, Inhibition of cuticular lipid synthesis and its effect on
insect survival, Arch. Insect. Biochem. Physiol., 25: 177-191
http://dx.doi.org/10.1002/arch.940250302 PMid:8167361
Kang S.C., Park S., and Lee D.G., 1998, Isolation and characterization of a
chitinase cDNA from the entomopathogenic fungus, Metarhizium
anisopliae, FEMS Microbiol. Lett., 165: 267-271 http://dx.doi.org/10.
1016/S0378-1097(98)00288-2 http://dx.doi.org/10.1111/j.1574-6968.
1998.tb13156.x PMid:9742698
Kang S.C., Park S., and Lee D.G., 1999, Purification and characterization of
a novel chitinase from the entomopathogenic fungus, Metarhizium
anisopliae, J. Invert. Pathol., 73: 276-281 http://dx.doi.org/10.1006/
jipa.1999.4843 PMid:10222181
Kang S.W., Lee S.H., Yoon C.S., and Kim S.W., 2005, Conidia production
by Beauveria bassiana during solid-state fermentation in a packed-bed
bioreactor, Biotechnol. Lett., 27: 135-139 http://dx.doi.org/10.1007/
s10529-004-7871-8 PMid:15703878
Khachatourians G.G., 1986, Production and use of biological pest control
agents, Tibtech., 12: 120-124 http://dx.doi.org/10.1016/0167-7799(86)
90144-7
Khachatourians G.G., 1991, Physiology and genetics of entomopathogenic
fungi, In: Arora D.K., Mukerji K.G., and Drouchet E. (eds.), Handbook
of Mycology, Marcel Dekker, New York, pp.613-663
Khachatourians G.G., 1996, Biochemistry and molecular biology of
entomopathogenic fungi, In: Howard D.H., and Miller J.D. (eds.),
Human and animal relationships, Mycota VI, Springer, Heidelberg,
pp.331-363
Khachatourians G.G., and Sohail S.Q., 2008, Entomopathogenic Fungi, In:
Brakhage A.A., and Zipfel P.F. (eds.), Biochemistry and molecular
biology, human and animal relationships, 2nd Edition. The Mycota VI,
Springer-Verlag, Berlin, Heidelberg
Kim H.K., Hoe H.S., Suh D.S., Kang S.C., Hwang C., and Kwon S.T., 1999,
Gene structure and expression of the gene from Beauveria bassiana
encoding bassiasin I, an insect cuticle-degrading serine protease,
Biotechnol. Lett., 21: 777-783 http://dx.doi.org/10.1023/A:1005519323748
Kiss L., 2003, A review of fungal antagonists of powdery mildews and their
potential as biocontrol agents, Pest Manag. Sci., 59: 475-483
http://dx.doi.org/10.1002/ps.689 PMid:12701710
Krasnoff S.B., Watson D.W., Gibson D.M., and Kwan E.C., 1995,
Behavioral effects of the entomopathogenic fungus, Entomophthora
muscae on its host Musca domestica: postural changes in dying hosts
and gated pattern of mortality, J. Insect. Physiol., 41: 895-903
http://dx.doi.org/10.1016/0022-1910(95)00026-Q
Kusunoki K., Kawai A., Aiuchi D., Koike M., Tani M., and Kuramochi K.,
2006, Biological control of Verticillium black-spot of Japanese radish
by entomopathogenic Verticillium lecanii (Lecanicillium spp.), Res.
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
77
Bull. Obihiro. Univ., 27: 99-107
Li W., and Sheng C., 2007, Occurrence and distribution of entomo-
phthoralean fungi infecting aphids in mainland China, Biocon. Sci.
Technol., 17: 433-439 http://dx.doi.org/10.1080/09583150701213802
Lord J.C., 2001, Response of the wasp Cephalonomia tarsalis (Hymenoptera:
Bethylidae) to Beauveria bassiana (Hyphomycetes: Moniliales) as
free conidia or infection in its host, the sawtoothed grain beetle,
Oryzaephalus surinamensis (Coleoptera: Sivanidae), Biological.
Control., 21: 300-304 http://dx.doi.org/10.1006/bcon.2001.0942
Lord J.C., Anderson S., and Stanley D.W., 2002, Eicosanoids mediate
Manduca sexta cellular response to the fungal pathogen Beauveria
bassiana: a role for the lipoxygenase pathway, Arch. Insect. Biochem.
Physiol., 51: 46-54 http://dx.doi.org/10.1002/arch.10049 PMid:12210960
Ludwig S.W., and Oetting R.D., 2001, Susceptibility of natural enemies to
infection by Beauveria bassiana and impact of insecticides on
Ipheseius degenerans (Acari: Phytoseiidae), Journal of Agricultural
and Urban Entomology, 18: 169-178
Magalhaes B.P., Lord J.C., Wraight S.P., Daoust R.A., and Roberts D.W.,
1988, Pathogenicity of Beauveria bassiana and Zoophthora radicans
to the coccinellid predator Coleomegilla maculate and Eriopis connexa,
Journal of Invertebrate Pathology, 52: 471-473 http://dx.doi.org/10.
1016/0022-2011(88)90060-2
Miller T.C., Gubler W.D., Laemmlen F.F., Geng S., and Rizzo D.M., 2004,
Potential for using Lecanicillium lecanii for suppression of strawberry
powdery mildew, Biocon. Sci. Technol., 14: 215-220 http://dx.doi.
org/10.1080/09583150310001639204
Milner R.J., 1997, Prospects for biopesticides for aphid control,
Entomophaga, 42: 227-239 http://dx.doi.org/10.1007/BF02769900
Mukherjee P.K., and Seshan K.R., 2001, Reintroduction of the PLB1 gene
into Candida albicans restores virulence in vivo, Microbiology, 147:
2585-2597 PMid:11535799
Murphy B., Von Damm-Kattari D., and Parrella M., 1999, Interaction
between fungal pathogens and natural enemies: Implication for
combined biocontrol of greenhouse pests, IOBC/wprs Bulletin, 22:
181-184
Nahar P., Ghormade V., and Deshpande M.V., 2004, The extracellular
constitutive production of chitin deacetylase in Metarhizium
anisopliae: possible edge to entomopathogenic fungi in the biological
control of insect pests, J. Invert. Pathol., 85: 80-88 http://dx.doi.
org/10.1016/j.jip.2003.11.006 PMid:15050837
Nam J.S., Lee D.H., Lee K.H., Park H.M., and Bae K.S., 1998, Cloning and
phylogenic analysis of chitin synthase genes from the insect
pathogenic fungus, Metarhizium anisopliae var. anisopliae, FEMS
Microbiol. Lett., 159: 77-84 http://dx.doi.org/10.1111/j.1574-6968.
1998.tb12844.x PMid:9485597
Nuutinen V., Tyni-Juslin J., Vanninen I., and Vainio A., 1991, The effects of
four entomopathogenic fungi and an entomoparasitic nematode on the
hatching of earthworm (Aporrectodea caliginosa ) cocoons in
laboratory, Journal of Invertebrate Pathology, 58: 147-149 http://dx.
doi.org/10.1016/0022-2011(91)90173-N
Ownley B.H., Kimberly D.G., and Fernando E.V., 2010, Endophytic fungal
entomopathogens with activity against plant pathogens: ecology and
evolution, BioCon., 55: 113-128 http://dx.doi.org/10.1007/s10526-009-
9241-x
Ownley B.H., Pereira R.M., Klineman W.E., Quigley N.B., and Leckie B.M.,
2004, Beauveria bassiana, a dual purpose biocontrol organism, with
activity against insect pests and plant pathogens. In: Lartey R.T., and
Caeser A. (eds.), Emerging Concepts in Plant Health Management,
Research Signpost, pp.255-269
Parker B.L., Skinner M., Gouli V., and Brownbridge M., 1997, Impact of
soil applications of Beauveria bassiana and Mariannaea sp. on
nontarget forest arthropods, Biological Control, 8: 203-206 http://dx.
doi.org/10.1006/bcon.1997.0516
Pava-Ripoll M., Posada F., Momen B., Wang C., and St. Leger R.J., 2008,
Increased pathogenicity against coffee berry borer, Hypothenemus
hampei (Coleoptera: Curculionidae) by Metarhizium anisopliae expressing
the scorpion toxin (AaIT) gene, J. Invertebr. Pathol., 99(2): 220-226
http://dx.doi.org/10.1016/j.jip.2008.05.004 PMid:18597773
Pingel R.L., and Lewis L.C., 1996, The fungus Beauveria bassiana
(Balsamo) Vuillemin in a corn ecosystem: its effect on the insect
predator Coleomegilla maculate De Geer., Biological. Control., 6:
137-141 http://dx.doi.org/10.1006/bcon.1996.0017
Poprawski T.J., Crisostomo L.J., Parker P.E., 1998, Influence of
entomopathogenic fungi on Serangium parcesetosum (Coleoptera:
Coccinellidae), an Important Predator of Whiteflies (Homoptera:
Aleyrodidae), Environmental Entomology, 27: 785-795
Qazi S.S., and Khachatourians G.G., 2005, Insect pests of Pakistan and their
management practices: prospects for the use of entomopathogenic
fungi, Biopest Int., 1: 13-24
Rangel D.E., Braga G.U., Anderson A.J., and Roberts D.W., 2005, Influence
of growth environment on tolerance to UVB radiation, germination
speed, and morphology of Metarhizium anisopliae var. acridum
conidia, J. Invert. Pathol., 90: 55-58 http://dx.doi.org/10.1016/j.jip.
2005.05.005 PMid:16005467
Richard J.S., Neal T.D., Karl J.K., and Michael R.K., 2010, Model reactions
for insect cuticle sclerotization: participation of amino groups in the
cross-linking of Manduca sexta cuticle protein MsCP36, Insect.
Biochem. and Molec. Bio., 40: 252-258 http://dx.doi.org/10.1016/j.
ibmb.2010.02.008 PMid:20219676
Roberts D.W., 1981, Toxins of entomopathogenic fungi. In: Burges H.D.
(eds.), Microbial Control of Pests and Plant Diseases 1970-1980,
Academic Press, New York, pp.441-464
Roberts D.W., and St. Leger R.J., 2004, Metarhizium spp., cosmopolitan
insect-pathogenic fungi: mycological aspects, Adv. Appl. Microbiol.,
54: 1-70 http://dx.doi.org/10.1016/S0065-2164(04)54001-7
Roy H.E., Steinkraus D.C., Eilenberg J., Hajek A.E., and Pell J.K., 2006,
Bizarre interactions and endgames: entomopathogenic fungi and their
arthropod hosts, Annu. Rev. Entomol., 51: 331-357 http://dx.doi.org/
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
78
10.1146/annurev.ento.51.110104.150941 PMid:16332215
Screen S., Bailey A., Charnley K., Cooper R., and Clarkson J., 1997, Carbon
regulation of the cuticle-degrading enzyme PR1 from Metarhizium
anisopliae may involve a trans-acting DNA-binding protein CRR1, a
functional equivalent of the Aspergillus nidulans CREA protein, Curr.
Genet., 31: 511-518 http://dx.doi.org/10.1007/s002940050238 PMid:
9211795
Screen S., Bailey A., Charnley K., Cooper R., and Clarkson J., 1998,
Isolation of a nitrogen response regulator gene (nrr1) from
Metarhizium anisopliae, Gene, 221: 17-24 http://dx.doi.org/10.1016/
S0378-1119(98)00430-2
Screen S.E., Hu G., and St Leger R.J., 2001, Transformants of Metarhizium
anisopliae sf. anisopliae overexpressing chitinase from Metarhizium
anisopliae sf. Acridum show early induction of native chitinase but are
not altered in pathogenicity to Manduca sexta, J. Invert. Pathol., 78:
260-266 http://dx.doi.org/10.1006/jipa.2001.5067 PMid:12009808
Shah P.A., and Pell J.K., 2003, Entomopathogenic fungi as biological
control agents, Applied Microbio. and Biotechnol., 61: 413-423
PMid:12764556
Sheng J., An K., Deng C., Li W., Bao X., and Qiu D., 2006, Cloning a
cuticle-degrading serine protease gene with biologic control function
from Beauveria brongniartii and its expression in Escherichia coli,
Curr. Microbiol., 53: 124-128 http://dx.doi.org/10.1007/s00284-005-
5336-5 PMid:16832726
Shipp J.L., Zhang Y., Hunt D.W.A., and Ferguson G., 2003, Influence of
humidity and greenhouse microclimate on the efficacy of Beauveria
bassiana (Balsamo) for control of greenhouse arthropod pests,
Environmental Entomology, 32: 1154-1163 http://dx.doi.org/10.1603/
0046-225X-32.5.1154
Small C.L.N., and Bidochka M.J., 2005, Up-regulation of Pr1, a
subtilisin-like protease, during conidiation in the insect pathogen
Metarhizium anisopliae, Mycol Res., 109: 307-313 http://dx.doi.org/
10.1017/S0953756204001856 PMid:15912947
Spencer D.M., and Atkey P.T., 1981, Parasitic effects of Verticillium lecanii
on two rust fungi, Trans. Br. Mycol. Soc., 77: 535-542
http://dx.doi.org/10.1016/S0007-1536(81)80101-5
St Leger R.J., and Wang C., 2009, Entomopathogenic fungi and the genomic
era, In: Stock S.P., Vandenberg J., Glazer I., and Boemare N. (eds.),
Insect Pathogens: Molecular Approaches and Techniques. CABI,
Wallingford, UK, pp.366-400 http://dx.doi.org/10.1079/9781845934781.
0365
St Leger R.J., Joshi L., Bidochka M.J., and Roberts D.W., 1996,
Construction of an improved mycoinsecticide overexpressing a toxic
protease, Proceedings of the National Academy of sciences of the
United States of America, 93: 6349-6354 http://dx.doi.org/10.1073/
pnas.93.13.6349
Staats C.C., Silva M.S., Pinto P.M., Vainstein M.H., and Schrank A., 2004,
The Metarhizium anisopliae trp1 gene: cloning and regulatory analysis,
Curr. Microbiol., 49: 66-70 http://dx.doi.org/10.1007/s00284-004-4256-0
Steenberg T., Langer V., and Esbjerg P., 1995, Entomopathogenic fungi
in predatory beetles (Col.: Carabidae and Staphylinidae) from
agricultural fields, Entomophaga., 40: 77-85 http://dx.doi.org/10.1007/
BF02372683
Stehr F., Kretschmar M., Kroger C., Hube B., and Schafer W., 2003,
Microbial lipases as virulence factors, J. of Molec. Catalysis B: Enzy.,
22: 347-355 http://dx.doi.org/10.1016/S1381-1177(03)00049-3
Thomas M.B., and Read A.F., 2007, Can fungal biopesticides control
malaria? Nat. Rev. Microbiol., 5: 377-383 http://dx.doi.org/10.1038/
nrmicro1638 PMid:17426726
Todorova S.I., Cloutier C., Cote J.C., and Coderre D., 2002, Pathogenicity
of six isolates of Beauveria bassiana (Balsamo) Vuillemin
(Deuteromycotina, Hyphomycetes) to Perillus bioculatus (F.) (Hem.,
Pentatomidae), Journal of Applied Entomology, 126: 182 -185
http://dx.doi.org/10.1046/j.1439-0418.2002.00632.x
Traugott M., Weissteiner S., and Strasser H., 2005, Effects of the
entomopathogenic fungus Beauveria brongniartii on the non-target
predator Poecilus versicolor (Coleoptera: Carabidae), Biological
Control, 33: 107-112 http://dx.doi.org/10.1016/j.biocontrol.2005.01.011
Uribe D., and Khachatourians G.G., 2008, Identification and characterization
of an alternative oxidase in the entomopathogenic fungus Metarhizium
anisopliae, Can. J. Microbiol., 54: 1-9 http://dx.doi.org/10.1139/W07-
127 PMid:18388981
Urtz B.E., and Rice W.C., 2000, Purification and characterization of a novel
extracellular protease from Beauveria bassiana, Mycol. Res., 104:
180-186 http://dx.doi.org/10.1017/S0953756299001215
Valadares-Inglis M.C., and Peberdy J.F., 1997, Location of chitinolytic
enzymes in protoplasts and whole cells of the entomopathogenic
fungus Metarhizium anisopliae, Mycol. Res., 101: 1393-1396
http://dx.doi.org/10.1017/S0953756297004243
Vandenberg J.D., 1990, Safety of four entomopathogens for caged adult
honey bees (Hymenoptera: Apidae), Journal of Economic Entomology,
83: 755-759
Vey A., Hoagland R., and Butt T.M., 2001, Toxic metabolites of fungal
biocontrol agents, In: Butt T.M., Jackson C.W., and Magan N. (eds.),
Fungi as biocontrol agents, CAB International, Wallingford, pp.311-
345 http://dx.doi.org/10.1079/9780851993560.0311
Wallner K., 1988, Gefahren für die Honigbiene durch den maikäfer-
bekämpfungsversuch im forstbezirk karlsruhe-Hardt. mitteilungen der
Forstlichen versuchs- und forschungsanstalt baden-württemberg,
Freiburg/B, 132: 155-163
Wang C., and St Leger R.J., 2006, A collagenous protective coat enables
Metarhizium anisopliae to evade insect immune responses, Proc. Natl.
Acad Sci. USA, 103: 6647-6652 http://dx.doi.org/10.1073/pnas.
0601951103 PMid:16614065 PMCid:1458935
Wang C., and St. Leger R.J., 2007a, The Metarhizium anisopliae perilipin
homolog MPL1 regulates lipid metabolism, appressorial turgor
pressure, and virulence, J. Biol. Chem., 282: 21110-21115 http://dx.doi.
org/10.1074/jbc.M609592200 PMid:17526497
Molecular Plant Breeding 2012, Vol.3, No.7, 63-79
http://mpb.sophiapublisher.com
79
Wang C., and St. Leger R.J., 2007b, The Metarhizium anisopliae perilipin
homolog MPL1 regulates lipid metabolism, appressorial turgor
pressure, and virulence, J. Biol. Chem., 282: 21110-21115
http://dx.doi.org/10.1074/jbc.M609592200 PMid:17526497
Wang C., and St. Leger R.J., 2007c, A scorpion neurotoxin increases the
potency of a fungal insecticide, Nat. Biotechnol., 25: 1455-1456
http://dx.doi.org/10.1038/nbt1357 PMid:17994009
Wang C., Hu G., and St. Leger R.J., 2005, Differential gene expression by
Metarhizium anisopliae growing in root exudate and host (Manduca
sexta) cuticle or hemolymph reveals mechanisms of physiological
adaptation, Fungal Genet. Biol., 42(8): 704-718 http://dx.doi.org/
10.1016/j.fgb.2005.04.006 PMid:15914043
Wang C.S., Skrobek A., and Butt T.M., 2004, Investigations on the destruxin
production of the entomopathogenic fungus Metarhizium anisopliae, J.
Invert. Pathol., 85: 168-174 http://dx.doi.org/10.1016/j.jip.2004.02.008
PMid:15109899
Wang Y., Crocker R.L., Wilson L.T., Smart G., Wie X., Nailon W.T., and
Cobb P.P., 2001, Effect of nematode and fungal treatments on
nontarget turfgrass-inhabiting arthropod and nematode populations,
Environmental Entomology, 30: 196-203 http://dx.doi.org/10.1603/
0046-225X-30.2.196
Wraight S.P., and Carruthers R.I., 1999, Production, delivery, and use of
mycoinsecticides for control of insect pests of field crops. In: Hall F.R.,
and Menn, J.J. (eds.), Biopesticides: Use and delivery, Humana Press,
Totowa, New Jersey, pp.233-269
Wraight S.P., Jackson M.A., and de Kock S.L., 2001, Production,
stabilization and formulation of fungal biological agents, In: Butt T.M.,
Jackson C., and Magan N. (eds.), Fungi as Biocontrol Agents, CABI,
Wallingford, pp.253-287 http://dx.doi.org/10.1079/9780851993560.0253
Ying S.H., and Feng M.G., 2004, Relationship between thermotolerance and
hydrophobin-like proteins in aerial conidia of Beauveria bassiana and
paecilomyces fumosoroseus as fungal biocontrol agents, J. App.l
Microbiol., 97: 323-331 http://dx.doi.org/10.1111/j.1365-2672.2004.
02311.x PMid:15239698
Yokoyama E., Yamagishi K., and Hara A., 2002, Group-I intron containing a
putative homing endonuclease gene in the small subunit ribosomal
DNA of Beauveria bassiana IFO 31676, Mol Biol Evol, 19:
2022-2025 http://dx.doi.org/10.1093/oxfordjournals.molbev.a004025
PMid:12411610
Zimmermann G., 2007, Review on safety of the entomopathogenic fungus
Beauveria bassiana and Beauveria brongniartii, Biocontrol Sci.
Technol., 17: 553-596 http://dx.doi.org/10.1080/09583150701309006
... Entomopathogenic fungi are microorganisms that are used first as a biological pest control agent. More than 700 species from 90 genera of fungi are pathogenic to insects (Khan, et al, 2012). Most species of entomopathogenic fungi derived from the division Ascomycota and Zygomycota. ...
... Its main constituent insect cuticle chitin and protein degradation by protease and a peptidase enzyme. Another role as a growth factor saprophytic fungi, propanol oxidase activation in the hemolymph and as a virulence factor of fungi (Khan, et al, 2012). The main component of insect cuticle is the chitin substance. ...
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This research was conducted in two stages. The research method is the isolation and application of biopesticide. In the first stage aims to isolate entomopathogenic fungi Beauveria bassiana around Berastagi vegetable farms and grow on agar and corn mashed artificial medium. Testing the virulence of Beauveria bassiana in vitro in several types of vegetable pests before it is applied on agricultural land. In phase II aims to application B. bassiana in the vegetable patch. In the in vitro treatment, the ability to infect insects beauvria average reached 75%. , Controls on crop lands, in the third week began their Crocidolomia pests that attack the growing point so that the cabbage plants fail to bloom. Average cropland applied biopesticides B. bassiana has been no attack. At week 7 attacks on control plants reach 13 plants or 17.3%. In field applied while Beauveria bassiana attack reached six plants, or about 8%.
... Fungal-based biopesticides thus lend to both inoculative (applied at very low concentration and with an autonomous population increase) and augmentative (low concentration but the environment is modified to favour their development) applications (Cook 2000). (4) Entomopathogenic fungi have long persistence in the soil and therefore a long-term suppression activity (Khan et al. 2012). Mycoinsecticides are yet to make a dent in the biopesticide market considering the impetus given to biological control in IPM. ...
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The use of microbial organisms as biological control agents has progressed significantly since Metschnikoff launched the first attempt at microbial insect control with Metarhizium anisopliae in 1879. Following the lead of Metschnikoff, entomopathogenic nematodes, fungi, bacteria and viruses have been extensively studied for commercialization and practical use as biopesticides in inundative releases against insect pests in various cropping systems. However, compared with chemical insecticides, these microbial products represent less than 2% of the total insecticide market share. Factors such as control efficacy, cost, formulation, shelf life, application techniques, and persistence have limited the commercial use of these microbial control agents in insect pest management. This review discusses research advances for entomopathogens, especially commercialization, formulation and application techniques, for microbial biocontrol of insect pests in the horticultural ecosystem.
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Biological pesticides are increasingly finding therr place in IPM and increasing numbers of products are making therr way to the marketplace. Particularly in China, Latin America and Australia, implementation is proceeding on a large scale. However, in the USA and Europe, registration procedures for insect pathogens to be used for insect control have been established that requrre low levels of risk, resulting in costs of retarding the implementation of microbial agents. This book provides a review of the state of the art of studies on the envrronmental impact of microbial insecticides. It originates from a Society for Invertebrate Pathology Microbial Control Division Symposium .. Assessment of envrronmental safety of biological insecticides", organised in collaboration with the EU-ERBIC research project (FAIR5-CT97-3489). This symposium was initiated by Heikki Hokkanen and Chris Lomer, and was held at the SIP Annual Meeting in 2001 in The Netherlands. The emphasis in this book is on large scale use of microbial agents for insect control, demonstrating how this use has been proceeding with minimal envrron­ mental impact. This book is intended to be of use to regulatory authorities in determining whether further studies in eertain areas are necessary and how to conduct them if needed, or whether sufficient information has been collected already to permit fuH registration of many of these biological control agents.
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Recent advances on mass culture, stabilization and formulation, and market potential of mycoinsecticides (Beauveria bassania [B. bassiana], B. brongniartii, Lagenidium giganteum, Metarhizium anisopliae, M. anisopliae var. acridum, Paecilomyces fumosoroseus and Verticillium lecanii), mycoherbicides (Colletotrichum gloeosporioides [Glomerella cingulata], Phytophthora palmivora, Puccinia canalichlata and Colletotrichum truncatum) and antagonistic yeasts (Candida oleophila and Cryptococcus albidus) for the control of many insect pests, weeds and postharvest diseases, are presented.
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The bacterium Bacillus sphaericus and the fungus Entomophaga maimaiga did not affect Apis mellifera longevity and did not cause disease among treated bees. Both of these microorganisms are considered safe for honey bees. A technical powder and a formulated product of the bacterium Bacillus thuringiensis var. tenebrionis reduced bee longevity at the higher concentration tested (108 spores/ml sucrose syrup), but did not cause disease. The fungus Beauveria bassiana reduced bee longevity at the 2 highest concentrations tested and caused mycosis among treated bees at all 3 concentrations tested (106-108 spores per bee). -from Author
Chapter
In this chapter we present as an example a specific case study from the ecological safety evaluation of the Hyphomycete fungi Metarhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuill., carried out in Finland during the ERBIC-research project. Only the part concerning the safety to bumblebees is presented here (for a full report see Hokkanen et al., 2003). Metarhizium anisopliae and Beauveria bassiana are two well-studied, commercialised, and commonly used entomopathogenic fungi (EPF), also occurring naturally in Finland. We decided to focus on bumblebees because they are the most important group of natural pollinators of crop plants and wild flowers in the temperate zone. While possible impacts of Metarhizium and Beauveria on the honeybee have been addressed by several authors in many publications, to our knowledge no earlier information exists on the possible impact of these fungal pathogens on bumblebees. These pollinators are also abundant in our model agroecosystem, turnip oilseed rape, which was chosen because both the key pest, the pollen beetle (Meligethes aeneus), and its natural enemy complex have been well studied under Scandinavian conditions. Background information was already available on the occurrence of deuteromycetous EPF in the model system (Vä nninen et al. 1989), on the persistence of augmented fungal propagules in cultivated soils of the study area in question (southern Finland) (Vänninen et al. 2000), and on the impact of entomopathogenic fungi on the pollen beetle (Hokkanen 1993). In addition, entomopathogenic fungi and nematodes are a possible future option for managing the soil-dwelling stages of the pollen beetle and other pests in this system via incorporation in the soil (Butt et al. 1994). Fungi can also be used against foliage-dwelling stages of the pest either by spraying, or when vectored by honeybees (Butt et al. 1998). Different application strategies for entomopathogens could therefore be considered, linked to differing non-target risk scenarios based on the impact of the application strategies on key components of the ecosystem.
Chapter
Fungal disease of insects represents an important facet of the interaction between entomopathogenic fungi (EPF) and their hosts. Altogether some 90 genera and 700 species are involved with entomopathogenicity, but only a few members of the entomophthorales and hyphomycetes have been well studied (Khachatourians 1991). The long-range potential of the EPF in research is their application in insect pest management or biocontrol (Leathers et al. 1993). Commercialization of EPF for pest control requires understanding of physiological aspects of growth, metabolic activity, genetic basis of virulence and host specificity-challenges that were forecast to be met with the new biotechnology (Khachatourians 1986; Boucias 1988). With such knowledge, physiological manipulations, isolation of mutants with enhanced virulence, and construction of environmentally safe strains with limited persistence should be possible within the forseeable future.
Chapter
Insects are members of the Arthropoda. Among the characteristics of this phyllum is the presence of an external skeleton or cuticle. Because of its location, the cuticle serves a variety of functions in addition to the skeletal roles of support and muscle anchorage. The defensive capability of the cuticle is clear since only one group of entomopathogens, the fungi, have acquired the ability to invade insects actively via this route. The other major groups of disease-causing microorganisms, the viruses and bacteria, are restricted primarily to the alimentary canal, where the midgut provides an exposed mucosal surface.