Agricultural and Biological Sciences Insect Science

Entomopathogenic Microorganisms in Pest Control

Description

This cluster of papers explores the use of entomopathogenic fungi, such as Metarhizium and Beauveria bassiana, as biocontrol agents for insect pests. It covers topics such as biological control, genomic sequencing, endophytic colonization, and the use of nematodes as biocontrol agents. The research also delves into the ecological factors, safety, and potential applications of these fungi in integrated pest management.

Keywords

Entomopathogenic Fungi; Biological Control; Insect Pathogens; Biopesticides; Metarhizium; Beauveria bassiana; Genomic Sequencing; Insect-Pathogenic Bacteria; Endophytic Colonization; Nematodes as Biocontrol Agents

1Department of Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA; 2Lethbridge Research Centre, Agriculture and Agri-Food Canada, PO Box 3000, Lethbridge, Alberta T1J 4B1, Canada; 3School … 1Department of Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA; 2Lethbridge Research Centre, Agriculture and Agri-Food Canada, PO Box 3000, Lethbridge, Alberta T1J 4B1, Canada; 3School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK; 4Institute of Microbiology, LeopoldFranzens University Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
Partial table of contents: Interactions Among Insects, Plants, and Microorganisms: A Net Effects Perspective on Insect Performance (C. Jones). PLANT MUTUALISTS. Ecosystem Perspectives, Soil Organisms, and Herbivores (J. Moore, et … Partial table of contents: Interactions Among Insects, Plants, and Microorganisms: A Net Effects Perspective on Insect Performance (C. Jones). PLANT MUTUALISTS. Ecosystem Perspectives, Soil Organisms, and Herbivores (J. Moore, et al.). Fungal Endophytes, Grasses, and Herbivores (K. Clay). PLANT PATHOGENS. Specific or Generalized Plant Defense: Reciprocal Interactions Between Herbivores and Pathogens (V. Krischik). Plant Pathogens and Nonvector Herbivores (P. Barbosa). INSECT MUTUALISTS. Symbiont--Mediated Detoxification in Insect Herbivores (P. Dowd). Role of Microorganisms in Spruce Bark Beetle--Conifer Interactions (A. Leufven). INSECT PATHOGENS. Host--Plant--Mediated Interactions Between the Gypsy Moth and a Baculovirus (J. Schultz & S. Keating). Index.
Metarhizium anisopliae, the type species of the anamorph entomopathogenic genus Metarhizium, is currently composed of four varieties, including the type variety, and had been demonstrated to be closely related to … Metarhizium anisopliae, the type species of the anamorph entomopathogenic genus Metarhizium, is currently composed of four varieties, including the type variety, and had been demonstrated to be closely related to M. taii, M. pingshaense and M. guizhouense. In this study we evaluate phylogenetic relationships within the M. anisopliae complex, identify monophyletic lineages and clarify the species taxonomy. To this end we have employed a multigene phylogenetic approach using near-complete sequences from nuclear encoded EF-1alpha, RPB1, RPB2 and beta-tubulin gene regions and evaluated the morphology of these taxa, including ex-type isolates whenever possible. The phylogenetic and in some cases morphological evidence supports the monophyly of nine terminal taxa in the M. anisopliae complex that we recognize as species. We propose to recognize at species rank M. anisopliae, M. guizhouense, M. pingshaense, M. acridum stat. nov., M. lepidiotae stat. nov. and M. majus stat. nov. In addition we describe the new species M. globosum and M. robertsii, resurrect the name M. brunneum and show that M. taii is a later synonym of M. guizhouense.
Abstract The ‘ Galleria bait method’ originally described for trapping of entomoparasitic nematodes in soil has been used successfully also for the detection of naturally occurring entomopathogenic fungi. In many … Abstract The ‘ Galleria bait method’ originally described for trapping of entomoparasitic nematodes in soil has been used successfully also for the detection of naturally occurring entomopathogenic fungi. In many soil samples several species, such as Beauveria bassiana, Metarrhizium anisopliae or Paecilomyces fumosoroseus , could be detected. This method can be applied for various ecological studies independent of the season and the occurrence of soil inhabiting host insects. Zusammenfassung Die “Galleria‐Köder‐Methode” zum Nachweis von insektenpathogenen Pilzen im Boden Die ursprünglich zur Entdeckung von insektenparasitischen Nematoden im Boden entwickelte “ Galleria ‐Köder‐Methode” wurde auch zum Nachweis von natürlich vorkommenden insektenpathogenen Pilzen erfolgreich cingesetzt. Mit Hilfe dieses Verfahrens konnten mehrere Arten, wie Beauveria bassiana, Metarrhizium anisopliae oder Paecilomyces fumosoroseus , in zahlreichen Bodenproben nachgewiesen werden. Die Methode kann unabhängig von der Jahreszeit und vom Vorhandensein von bestimmten Wirtsinsekten im Boden für unterschiedliche ökologische Untersuchungen angewendet werden.
Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such … Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti) curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis.
The entomopathogenic fungus Metarhizium anisopliae (Metschn.) Sorokin is widely used for biocontrol of pest insects, and many commercial products are on the market or under development. The aim of this … The entomopathogenic fungus Metarhizium anisopliae (Metschn.) Sorokin is widely used for biocontrol of pest insects, and many commercial products are on the market or under development. The aim of this review is to summarise all relevant safety data of this fungus, which are necessary for the commercialisation and registration process. The review contains the following sections: (1) identity, (2) biological properties (history, natural occurrence and geographical distribution, host range, mode of action, production of metabolites/toxins, effect of environmental factors), (3) methods to determine and quantify residues, (4) fate and behaviour in the environment (mobility and persistence in air, water and soil), (5) effects on non-target organisms (microorganisms, plants, soil organisms, aquatic organisms, predators, parasitoids, honey bees, earth worms, etc.), (6) effects on vertebrates (fish, amphibia, reptiles, and birds), and (7) effects on mammals and human health (allergy, pathogenicity/toxicity). On the basis of the presented knowledge, M. anisopliae is considered to be safe with minimal risks to vertebrates, humans and the environment.
The ascomycete fungus Beauveria bassiana is a pathogen of hundreds of insect species and is commercially produced as an environmentally friendly mycoinsecticide. We sequenced the genome of B. bassiana and … The ascomycete fungus Beauveria bassiana is a pathogen of hundreds of insect species and is commercially produced as an environmentally friendly mycoinsecticide. We sequenced the genome of B. bassiana and a phylogenomic analysis confirmed that ascomycete entomopathogenicity is polyphyletic, but also revealed convergent evolution to insect pathogenicity. We also found many species-specific virulence genes and gene family expansions and contractions that correlate with host ranges and pathogenic strategies. These include B. bassiana having many more bacterial-like toxins (suggesting an unsuspected potential for oral toxicity) and effector-type proteins. The genome also revealed that B. bassiana resembles the closely related Cordyceps militaris in being heterothallic, although its sexual stage is rarely observed. A high throughput RNA-seq transcriptomic analysis revealed that B. bassiana could sense and adapt to different environmental niches by activating well-defined gene sets. The information from this study will facilitate further development of B. bassiana as a cost-effective mycoinsecticide.
Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a … Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a comparative analysis of the genome sequences of the broad-spectrum insect pathogen Metarhizium anisopliae and the acridid-specific M. acridum. Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens. Both M. anisopliae and M. acridum have a strikingly larger proportion of genes encoding secreted proteins than other fungi, while ∼30% of these have no functionally characterized homologs, suggesting hitherto unsuspected interactions between fungal pathogens and insects. The analysis of transposase genes provided evidence of repeat-induced point mutations occurring in M. acridum but not in M. anisopliae. With the help of pathogen-host interaction gene database, ∼16% of Metarhizium genes were identified that are similar to experimentally verified genes involved in pathogenicity in other fungi, particularly plant pathogens. However, relative to M. acridum, M. anisopliae has evolved with many expanded gene families of proteases, chitinases, cytochrome P450s, polyketide synthases, and nonribosomal peptide synthetases for cuticle-degradation, detoxification, and toxin biosynthesis that may facilitate its ability to adapt to heterogenous environments. Transcriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity. Of particular note, M. acridum transcribed distinct G-protein coupled receptors on cuticles from locusts (the natural hosts) and cockroaches, whereas M. anisopliae transcribed the same receptor on both hosts. This study will facilitate the identification of virulence genes and the development of improved biocontrol strains with customized properties.
The commercial use of entomopathogenic fungi and their products as mycoinsecticides necessitates their registration. Worldwide, several registration guidelines are available, however, most of them focus on similar or even the … The commercial use of entomopathogenic fungi and their products as mycoinsecticides necessitates their registration. Worldwide, several registration guidelines are available, however, most of them focus on similar or even the same safety issues. With respect to the two entomopathogenic fungi, Beauveria bassiana (Bals.-Criv.) Vuill. and Beauveria brongniartii (Sacc.) Petch, many commercial products have been developed, and numerous papers on different biological, environmental, toxicological and other safety aspects have been published during the past 30–40 years. The aim of the present review is to summarise these data. The following safety issues are presented: (1) identity of Beauveria spp.; (2) biological properties of Beauveria spp. (history, natural occurrence and geographical distribution, host range, mode of action, production of metabolites/toxins, effect of environmental factors); (3) analytical methods to determine and quantify residues; (4) fate and behaviour in the environment (mobility and persistence in air, water and soil); (5) effects on non-target organisms (non-target microorganisms, plants, soil organisms, aquatic organisms, predators, parasitoids, honey bees, earth worms and nontarget arthropods); (6) effects on vertebrates (fish, amphibia, reptiles and birds); and (7) effects on mammals and human health. Based on the present knowledge it is concluded that both Beauveria species are considered to be safe.
▪ Abstract Control of grasshoppers and locusts has traditionally relied on synthetic insecticides, and for emergency situations this is unlikely to change. However, a growing awareness of the environmental issues … ▪ Abstract Control of grasshoppers and locusts has traditionally relied on synthetic insecticides, and for emergency situations this is unlikely to change. However, a growing awareness of the environmental issues associated with acridid control as well as the high costs of emergency control are expanding the demand for biological control. In particular, preventive, integrated control strategies with early interventions will reduce the financial and environmental costs associated with large-scale plague treatments. The recent development of effective oil formulations of Metarhizium anisopliae spores in Africa, Australia, and Brazil opens new possibilities for environmentally safe control operations. Metarhizium biopesticide kills 70%–90% of treated locusts within 14–20 days, with no measurable impact on nontarget organisms. An integrated pest management strategy, with an emphasis on the use of Metarhizium, that incorporates rational use of chemical pesticides with biological options such as the microsporidian Nosema locustae and the hymenopteran egg parasitoids Scelio spp., has become a realistic option.
Photorhabdus luminescens is a symbiont of nematodes and a broad-spectrum insect pathogen. The complete genome sequence of strain TT01 is 5,688,987 base pairs (bp) long and contains 4,839 predicted protein-coding … Photorhabdus luminescens is a symbiont of nematodes and a broad-spectrum insect pathogen. The complete genome sequence of strain TT01 is 5,688,987 base pairs (bp) long and contains 4,839 predicted protein-coding genes. Strikingly, it encodes a large number of adhesins, toxins, hemolysins, proteases and lipases, and contains a wide array of antibiotic synthesizing genes. These proteins are likely to play a role in the elimination of competitors, host colonization, invasion and bioconversion of the insect cadaver, making P. luminescens a promising model for the study of symbiosis and host-pathogen interactions. Comparison with the genomes of related bacteria reveals the acquisition of virulence factors by extensive horizontal transfer and provides clues about the evolution of an insect pathogen. Moreover, newly identified insecticidal proteins may be effective alternatives for the control of insect pests.
▪ Abstract Xenorhabdus and Photorhabdus spp. are gram negative gamma proteobacteria that form entomopathogenic symbioses with soil nematodes. They undergo a complex life cycle that involves a symbiotic stage, in … ▪ Abstract Xenorhabdus and Photorhabdus spp. are gram negative gamma proteobacteria that form entomopathogenic symbioses with soil nematodes. They undergo a complex life cycle that involves a symbiotic stage, in which the bacteria are carried in the gut of the nematodes, and a pathogenic stage, in which susceptible insect prey are killed by the combined action of the nematode and the bacteria. Both bacteria produce antibiotics, intracellular protein crystals, and numerous other products. These traits change in phase variants, which arise when the bacteria are maintained under stationary phase conditions in the laboratory. Molecular biological studies suggest that Xenorhabdus and Photorhabdus spp. may serve as valuable model systems for studying signal transduction and transcriptional and posttranscriptional regulation of gene expression. Such studies also indicate that these bacterial groups, which had been previously considered to be very similar, may actually be quite different at the molecular level.
Infections mediated by broad host range entomopathogenic fungi represent seminal observations that led to one of the first germ theories of disease and are a classic example of a co-evolutionary … Infections mediated by broad host range entomopathogenic fungi represent seminal observations that led to one of the first germ theories of disease and are a classic example of a co-evolutionary arms race between a pathogen and target hosts. These fungi are able to parasitize susceptible hosts via direct penetration of the cuticle with the initial and potentially determining interaction occurring between the fungal spore and the insect epicuticle. Entomogenous fungi have evolved mechanisms for adhesion and recognition of host surface cues that help direct an adaptive response that includes the production of: (a) hydrolytic, assimilatory, and/or detoxifying enzymes including lipase/esterases, catalases, cytochrome P450s, proteases, and chitinases; (b) specialized infectious structures, e.g., appressoria or penetrant tubes; and (c) secondary and other metabolites that facilitate infection. Aside from immune responses, insects have evolved a number of mechanisms to keep pathogens at bay that include: (a) the production of (epi) cuticular antimicrobial lipids, proteins, and metabolites; (b) shedding of the cuticle during development; and (c) behavioral-environmental adaptations such as induced fever, burrowing, and grooming, as well as potentially enlisting the help of other microbes, all intended to stop the pathogen before it can breach the cuticle. Virulence and host-defense can be considered to be under constant reciprocal selective pressure, and the action on the surface likely contributes to phenomena such as strain variation, host range, and the increased virulence often noted once a (low) virulent strain is "passaged" through an insect host. Since the cuticle represents the first point of contact and barrier between the fungus and the insect, the "action on the surface" may represent the defining interactions that ultimately can lead either to successful mycosis by the pathogen or successful defense by the host. Knowledge concerning the molecular mechanisms underlying this interaction can shed light on the ecology and evolution of virulence and can be used for rational design strategies at increasing the effectiveness of entomopathogenic fungi for pest control in field applications.
Fungal diseases in insects are common and widespread and often decimate insect populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases. Fungi infect insects by breaching … Fungal diseases in insects are common and widespread and often decimate insect populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases. Fungi infect insects by breaching the host cuticle; they are the principal pathogens among sucking insects because these hosts cannot ingest other pathogens that infect through the gut wall. Fungi are also particularly important for control of Coleoptera, because viral and bacterial diseases are rare among beetles. Entomopathogenic fungi are associated with insects living in diverse habitats, including fresh water, soil, soil surfaces, and aerial locations. Currently, widely publicized environmental concerns and health risks associated with use of synthetic chemical insecticides have stimulated efforts to develop biological-control agents as alternatives or supplements to these chemicals. Consequently, much recent interest in mycoinsecticides has led to the marketing of several of them. Nevertheless, of the 700 species of entomopathogenic fungi currently known, only 10 species have been, or are presently being, developed for control (85, 89, 101, 130, 136), and the full potential of entomopathogenic fungi has not been approached. To develop fungi for control purposes, we need to understand the requirements for the high levels of disease transmission in the field that are characteristic of epizootics. In-depth epizootiological studies of several systems have been undertaken, in some cases resulting in simulation models used for experi­ mentation with these complex systems as well as for development of control
ABSTRACT We describe allelic variation at 28 gene loci in natural populations of D. willistoni. Seventy samples were studied from localities extending from Mexico and Florida, through Central America, the … ABSTRACT We describe allelic variation at 28 gene loci in natural populations of D. willistoni. Seventy samples were studied from localities extending from Mexico and Florida, through Central America, the West Indies, and tropical South America, down to South Brazil. At least several hundred, and often several thousand, genomes were sampled for each locus. We have discovered a great deal of genetic variation. On the average, 58% loci are polymorphic in a given population. (A locus is considered polymorphic when the frequency of the most common allele is no greater than 0.95). An individual fly is heterozygous, on the average, at 18.4% loci.—Concerning the pattern of the variation, the most remarkable finding is the similarity of the configuration of allelic frequencies from locality to locality throughout the distribution of the species. Our observations support the conclusion that balancing natural selection is the major factor responsible for the considerable genetic variation observed in D. willistoni.
Xenorhabdus spp., entomopathogenic bacteria symbiotically associated with the nematodes Neoaplectana and Heterorhabditis, occur in two forms. In general, only one form, designated the primary form, is transmitted into new hosts … Xenorhabdus spp., entomopathogenic bacteria symbiotically associated with the nematodes Neoaplectana and Heterorhabditis, occur in two forms. In general, only one form, designated the primary form, is transmitted into new hosts by the infective stage of the nematode. The significance of the relationship between the two forms has been examined with X. nematophilus, the symbiont of N. feltiae. The forms of X. nematophilus can be differentiated by their colony characteristics but by only two biochemical tests. The two forms of X.nematophilus are equally pathogenic when injected into the haemocoel of Galleria larvae. However, the primary form when injected into Galleria larvae with axenic nematodes provides better conditions for reproduction of the nematodes than the secondary form, for which a role has not been determined. Although the primary form readily converts to the secondary form in vitro and occasionally in vivo, the secondary form is usually stable. Possible causes of the instability have been investigated.
Mycoinsecticides are being used for the control of many insect pests as an environmentally acceptable alternative to chemical insecticides. A key aim of much recent work has been to increase … Mycoinsecticides are being used for the control of many insect pests as an environmentally acceptable alternative to chemical insecticides. A key aim of much recent work has been to increase the speed of kill and so improve commercial efficacy of these biocontrol agents. This might he achieved by adding insecticidal genes to the fungus, an approach considered to have enormous potential for the improvement of biological pesticides. We report here the development of a genetically improved entomopathogenic fungus. Additional copies of the gene encoding a regulated cuticle-degrading protease (Pr1) from Metarhizium anisopliae were inserted into the genome of M. anisopliae such that Pr1 was constitutively overproduced in the hemolymph of Manduca sexta, activating the prophenoloxidase system. The combined toxic effects of Pr1 and the reaction products of phenoloxidase caused larvae challenged with the engineered fungus to exhibit a 25% reduction in time of death and reduced food consumption by 40% compared to infections by the wild-type fungus. In addition, infected insects were rapidly melanized, and the resulting cadavers were poor substrates for fungal sporulation. Thus, environmental persistence of the genetically engineered fungus is reduced, thereby providing biological containment.
Beauveria is a globally distributed genus of soil-borne entomopathogenic hyphomycetes of interest as a model system for the study of entomopathogenesis and the biological control of pest insects. Species recognition … Beauveria is a globally distributed genus of soil-borne entomopathogenic hyphomycetes of interest as a model system for the study of entomopathogenesis and the biological control of pest insects. Species recognition in Beauveria is difficult due to a lack of taxonomically informative morphology. This has impeded assessment of species diversity in this genus and investigation of their natural history. A gene-genealogical approach was used to investigate molecular phylogenetic diversity of Beauveria and several presumptively related Cordyceps species. Analyses were based on nuclear ribosomal internal transcribed spacer (ITS) and elongation factor 1-alpha (EF1-alpha) sequences for 86 exemplar isolates from diverse geographic origins, habitats and insect hosts. Phylogenetic trees were inferred using maximum parsimony and Bayesian likelihood methods. Six well supported clades within Beauveria, provisionally designated A-F, were resolved in the EF1-alpha and combined gene phylogenies. Beauveria bassiana, a ubiquitous species that is characterized morphologically by globose to subglobose conidia, was determined to be non-monophyletic and consists of two unrelated lineages, clades A and C. Clade A is globally distributed and includes the Asian teleomorph Cordyceps staphylinidaecola and its probable synonym C. bassiana. All isolates contained in Clade C are anamorphic and originate from Europe and North America. Clade B includes isolates of B. brongniartii, a Eurasian species complex characterized by ellipsoidal conidia. Clade D includes B. caledonica and B. vermiconia, which produce cylindrical and comma-shaped conidia, respectively. Clade E, from Asia, includes Beauveria anamorphs and a Cordyceps teleomorph that both produce ellipsoidal conidia. Clade F, the basal branch in the Beauveria phylogeny includes the South American species B. amorpha, which produces cylindrical conidia. Lineage diversity detected within clades A, B and C suggests that prevailing morphological species concepts underestimate species diversity within these groups. Continental endemism of lineages in B. bassiana s.l. (clades A and C) indicates that isolation by distance has been an important factor in the evolutionary diversification of these clades. Permutation tests indicate that host association is essentially random in both B. bassiana s.l. clades A and C, supporting past assumptions that this species is not host specific. In contrast, isolates in clades B and D occurred primarily on coleopteran hosts, although sampling in these clades was insufficient to assess host affliation at lower taxonomic ranks. The phylogenetic placement of Cordyceps staphylinidaecola/bassiana, and C. scarabaeicola within Beauveria corroborates prior reports of these anamorph-teleomorph connections. These results establish a phylogenetic framework for further taxonomic, phylogenetic and comparative biological investigations of Beauveria and their corresponding Cordyceps teleomorphs.
Over the past 50 years, crop protection has relied heavily on synthetic chemical pesticides, but their availability is now declining as a result of new legislation and the evolution of … Over the past 50 years, crop protection has relied heavily on synthetic chemical pesticides, but their availability is now declining as a result of new legislation and the evolution of resistance in pest populations. Therefore, alternative pest management tactics are needed. Biopesticides are pest management agents based on living micro-organisms or natural products. They have proven potential for pest management and they are being used across the world. However, they are regulated by systems designed originally for chemical pesticides that have created market entry barriers by imposing burdensome costs on the biopesticide industry. There are also significant technical barriers to making biopesticides more effective. In the European Union, a greater emphasis on Integrated Pest Management (IPM) as part of agricultural policy may lead to innovations in the way that biopesticides are regulated. There are also new opportunities for developing biopesticides in IPM by combining ecological science with post-genomics technologies. The new biopesticide products that will result from this research will bring with them new regulatory and economic challenges that must be addressed through joint working between social and natural scientists, policy makers and industry.
▪ Abstract Invertebrate pathogens and their hosts are taxonomically diverse. Despite this, there is one unifying concept relevant to all such parasitic associations: Both pathogen and host adapt to maximize … ▪ Abstract Invertebrate pathogens and their hosts are taxonomically diverse. Despite this, there is one unifying concept relevant to all such parasitic associations: Both pathogen and host adapt to maximize their own reproductive output and ultimate fitness. The strategies adopted by pathogens and hosts to achieve this goal are almost as diverse as the organisms themselves, but studies examining such relationships have traditionally concentrated only on aspects of host physiology. Here we review examples of host-altered behavior and consider these within a broad ecological and evolutionary context. Research on pathogen-induced and host-mediated behavioral changes demonstrates the range of altered behaviors exhibited by invertebrates including behaviorally induced fever, elevation seeking, reduced or increased activity, reduced response to semiochemicals, and changes in reproductive behavior. These interactions are sometimes quite bizarre, intricate, and of great scientific interest.
of insect pests of crops were considered to be greater. This attitude probably can be explained by the increase in our knowledge of general microbiology, especially medical, with more emphasis … of insect pests of crops were considered to be greater. This attitude probably can be explained by the increase in our knowledge of general microbiology, especially medical, with more emphasis in the fields of bacteriology and virology than in mycology. However, for the past 15 years, research with the entomogenous fungi has bene­ fited from a renewed interest, which arose from a better understanding of the role of natural phenomena in the regulati on of insect populations, among which epizoot­ ics caused by fungi have played a d eterminant part in certain cases. Furtherm ore, there was a need to develop new techniques of biological control for the expanding application of the concepts of integrated control. Because of this there is an increasing number of scientific publications devoted to this problem. The acquisition of new knowledge and the evolution of research programs are so rapid that it is absolutely necessary to devote an ever-increasing effort to the analysis and compilation of the data contained in the literature. Since the majority of the publications concerning mycoses in insects are not in English, they suffer from a limited distribution. Although I cannot possibly pretend to have
The levels of DNA relatedness for a broad sample of Xenorhabdus strains isolated from different species of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) and from different geographical sources were estimated by … The levels of DNA relatedness for a broad sample of Xenorhabdus strains isolated from different species of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) and from different geographical sources were estimated by the hydroxyapatite method. The level of DNA-DNA relatedness for the two phases of each isolate tested was not significantly different from 100%, demonstrating unequivocally that the phase variation demonstrated by all Xenorhabdus spp. is not due to contamination. The isolates of the described Xenorhabdus species coalesced into different DNA relatedness groups, confirming that Xenorhabdus nematophilus, Xenorhabdus bovienii, Xenorhabdus poinarii, and Xenorhabdus beddingii, defined on the basis of phenotypic differences, are valid species. The symbiont of Steinemema intermedia also coalesced with the X. bovienii isolates. This was the only symbiont of seven recently described and unamed Steinemema spp. (including Steinemema ritteri, Steinemema rara, and Steinemema anomali) that formed a group with any of the previously described Xenorhabdus species; new species descriptions are required to accommodate the other taxa, but too few isolates were available to allow satisfactory descriptions of them. The DNA relatedness data also showed that the bacteria currently classified as Xenorhabdus luminescens are significantly different from all other Xenorhabdus strains. These data strongly support indications from previous studies of phenotypic characteristics, cellular fatty acids, and DNA relatedness that X. luminescens should be classified as a separate genus. A new genus, Photorhabdus, with an amended description of the type species, Photorhabdus luminescens, is proposed.
This review summarizes the progress and achievements made in the last decade in mass production formulation and application technology of the entomopathogenic fungus Beauveria bassiana. Reports published on relevant research … This review summarizes the progress and achievements made in the last decade in mass production formulation and application technology of the entomopathogenic fungus Beauveria bassiana. Reports published on relevant research from Belgium, Canada, China, Cuba, Czechoslovakia (former), France, Germany, Great Britain, Philippines, Poland, Switzerland, USA and USSR (former) regarding this topic have been covered. Much of the non‐English language literature, particularly that from Eastern European and Chinese sources, has not been translated and is inaccessible to most English or other western language readers. We have done this translation and through this review provide technological details about mass production of B. bassiana in China. Various aspects of B. bassiana growth, substrate use, production of mycelia, conidiospore and blastospores, process technologies associated with separation, drying and milling, formulation, storage and 'shelf‐life', and field efficacy are reviewed. Data are presented on: a modified diphasic production technology developed in China during the 1980s; comparisons between submerged fermentation, which usually produces blastospores, and those producing conidia; the use of mycelial preparations pelletized with alginate or gelatinized with cornstarch or cornstarch‐oil; and data on low or ultra‐low volume sprays of emulsifiable or oil conidial suspensions and dust formulations. B. bassiana has proved to be competitive with chemical insecticides for the annual protection of 0.8–1.3 million hectares against forest and farm insect pests in China. It is hoped that this review will help to bridge the language gap between eastern and western scientists in microbial control using B. bassiana.
In augmentative biological control (ABC), invertebrate and microbial organisms are seasonally released in large numbers to reduce pests. Today it is applied on more than 30 million ha worldwide. Europe … In augmentative biological control (ABC), invertebrate and microbial organisms are seasonally released in large numbers to reduce pests. Today it is applied on more than 30 million ha worldwide. Europe is the largest commercial market for invertebrate biological control agents, while North America has the largest sales of microbials. A strong growth in use of ABC, particularly of microbial agents, is taking place in Latin America, followed by Asia. The current popularity of ABC is due to (1) its inherent positive characteristics (healthier for farm workers and persons living in farming communities, no harvesting interval or waiting period after release of agents, sustainable as there is no development of resistance against arthropod natural enemies, no phytotoxic damage to plants, better yields and a healthier product, reduced pesticide residues [well below the legal Maximum Residue Levels (MRLs)], (2) professionalism of the biological control industry (inexpensive large scale mass production, proper quality control, efficient packaging, distribution and release methods, and availability of many (>440 species) control agents for numerous pests), (3) a number of recent successes showing how biological control can save agricultural production when pesticides fail or are not available, (4) several non-governmental organizations (NGOs), consumers, and retailers demanding pesticide residues far below the legal MRLs, and (5) policy developments in several regions of the world aimed at reduction and replacement of synthetic pesticides by more sustainable methods of pest management. We are convinced, however, that ABC can be applied on a much larger area than it is today. We plead in the short term for a pragmatic form of agriculture that is adaptable, non-dogmatic and combines the sustainability gain from all types of agriculture and pest management methods. We then propose to move to "conscious agriculture", which involves participation of all stakeholders in the production and consumer chain, and respects the environment and resource availability for future generations. Were "conscious agriculture" to be considered a serious alternative to conventional farming, ABC would face an even brighter future.
Soil treatments with Metarhizium brunneum EAMa 01/58-Su strain conducted in both Northern and Southern Spain reduced the olive fly (Bactrocera oleae) population density emerging from the soil during spring up … Soil treatments with Metarhizium brunneum EAMa 01/58-Su strain conducted in both Northern and Southern Spain reduced the olive fly (Bactrocera oleae) population density emerging from the soil during spring up to 70% in treated plots compared with controls. A model to determine the influence of rainfall on the conidial wash into different soil types was developed, with most of the conidia retained at the first 5 cm, regardless of soil type, with relative percentages of conidia recovered ranging between 56 and 95%. Furthermore, the possible effect of UV-B exposure time on the pathogenicity of this strain against B. oleae adults coming from surviving preimaginals and carrying conidia from the soil at adult emergence was also evaluated. The UV-B irradiance has no significant effect on M. brunneum EAMa 01/58-Su pathogenicity with B. oleae adult mortalities of 93, 90, 79, and 77% after 0, 2, 4, and 6 of UV-B irradiance exposure, respectively. In a next step for the use of these M. brunneum EAMa 01/58-Sun soil treatments within a B. oleae IPM strategy, its possible effect of on the B. oleae cosmopolitan parasitoid Psyttalia concolor, its compatibility with the herbicide oxyfluorfen 24% commonly used in olive orchards and the possible presence of the fungus in the olive oil resulting from olives previously placed in contact with the fungus were investigated. Only the highest conidial concentration (1 × 108 conidia ml-) caused significant P. concolor adult mortality (22%) with enduing mycosis in 13% of the cadavers. There were no fungal propagules in olive oil samples resulting from olives previously contaminated by EAMa 01/58-Su conidia. Finally, the strain was demonstrated to be compatible with herbicide since the soil application of the fungus reduced the B. oleae population density up to 50% even when it was mixed with the herbicide in the same tank. The fungal inoculum reached basal levels 4 months after treatments (1.6 × 103 conidia g soil-1). These results reveal both the efficacy and environmental and food safety of this B. oleae control method, protecting olive groves and improving olive oil quality without negative effects on the natural enemy P. concolor.
In the past two decades, a great deal of information on the role of endophytic microorganisms in nature has been collected. The capability of colonizing internal host tissues has made … In the past two decades, a great deal of information on the role of endophytic microorganisms in nature has been collected. The capability of colonizing internal host tissues has made endophytes valuable for agriculture as a tool to improve crop performance. In this review, we addressed the major topics concerning the control of insects-pests by endophytic microorganisms. Several examples of insect control are described, notably those involving the interactions between fungi and grazing grasses from temperate countries. The mechanisms by which endophytic fungi control insect attacks are listed and include toxin production as well as the influence of these compounds on plant and livestock and how their production may be affected by genetic and environmental conditions. The importance of endophytic entomopathogenic fungi for insect control is also addressed. As the literature has shown, there is a lack of information on endophytes from tropical hosts, which are more severely affected by pests and diseases. Having this in mind, we have included an updated and extensive literature in this review, concerning new findings from tropical plants, including the characterization of endophytic fungi and bacteria microbiota from several Amazon trees, citrus and medicinal plants among others.
<title>Abstract</title> This book provides a comprehensive review of entomopathogenic nematology. It discusses the fundamental biology and taxonomic foundation for nematodes and their bacterial symbionts. The functional processes involved in parasitism … <title>Abstract</title> This book provides a comprehensive review of entomopathogenic nematology. It discusses the fundamental biology and taxonomic foundation for nematodes and their bacterial symbionts. The functional processes involved in parasitism and nematode ecology are also discussed. Technological advances and control methodologies are described.
Chemical control using synthetic insecticides is the most widely used method for controlling the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Sub-Saharan Africa (SSA). However, the application … Chemical control using synthetic insecticides is the most widely used method for controlling the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Sub-Saharan Africa (SSA). However, the application of insecticides is not a long-term or sustainable solution. Biological control is an important pillar of integrated pest management, and entomopathogenic fungi (EPFs) are becoming increasingly important as biocontrol agents. However, no EPF biopesticides have been registered in South Africa for the control of S. frugiperda. Few studies have been conducted on the efficacy of commercial formulations of biopesticides against all S. frugiperda life stages. The objective of this study was, therefore, to assess the potential of two Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae) and two Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) based commercial biopesticides registered in South Africa against other pests, for their efficacy against S. frugiperda. The effects of these EPF formulations were evaluated on larval and prepupal mortality, moth emergence, fecundity, and longevity of the emerged moths. The results indicated that S. frugiperda second- and sixth-instar larvae were not susceptible to the biopesticides. Moth emergence, fecundity, and longevity were not significantly affected. However, prepupae were susceptible to both Metarhizium formulations, with Metarhizium anisopliae ICIPE 78 resulting in the highest mortality (56.7%). This biopesticide holds potential for the management of S. frugiperda when applied to the soil for the control of pupating larvae.
Goal. To improve the methodological approach to the helminthological analysis of insects as an essential component of insect infectious pathologies, using the parasitic system «insect host Galleria mellonella — nematodes … Goal. To improve the methodological approach to the helminthological analysis of insects as an essential component of insect infectious pathologies, using the parasitic system «insect host Galleria mellonella — nematodes Rhabditida» as a case study. Methods. The methodological basis of the study comprises data from long-term original research on entomopathogenic nematodes (Nematoda: Rhabditida: Steinernematidae, Heterorhabditidae) in agroecosystems of Ukraine (conducted between 2016 and 2024), as well as current scientific literature by Ukrainian and international scholars on insect helminthodiagnostic methods. The study employed both general scientific and specialized research methods, including theoretical analysis, fieldwork, laboratory experiments, and mathematical-statistical techniques. Results. A scientific and methodological approach to helminthological analysis of insects (exemplified by Galleria mellonella L., 1758) within the context of insect infectious pathologies has been improved. This approach is based on the use of an original «entomohelminthological formula» for the assessment of the species composition and condition of helminths (Nematoda: Rhabditida) following a complete helminthological dissection of insects. Conclusions. The use of complete helminthological dissections in combination with the original «entomohelminthological formula» enables not only quantitative detailing but also qualitative characterization of pathological changes in insects (Insecta) associated with helminthic (nematode) infections (Nematoda). The results of the research can be applied in entomological studies after the collection and identification of insects infected with nematode parasites (pathogens).
ABSTRACT We report the complete genome sequence of Metarhizium marquandii strain ISA501, isolated from maize rhizosphere soil. The 42.8 Mb genome, assembled with hybrid sequencing, comprises eight chromosomes with 51.65% … ABSTRACT We report the complete genome sequence of Metarhizium marquandii strain ISA501, isolated from maize rhizosphere soil. The 42.8 Mb genome, assembled with hybrid sequencing, comprises eight chromosomes with 51.65% GC content. This high-quality resource provides insights into its plant growth-promoting potential, secondary metabolism, and ecological roles in sustainable agriculture.
Trichoderma spp., Metarhizium spp., and Bacillus spp. are commonly used as biocontrol microorganisms domestically and internationally. However, microbial pesticides currently prepared from single living microorganisms have problems such as a … Trichoderma spp., Metarhizium spp., and Bacillus spp. are commonly used as biocontrol microorganisms domestically and internationally. However, microbial pesticides currently prepared from single living microorganisms have problems such as a short shelf life, particularly under stressful environment conditions. Secondary metabolites produced from biocontrol microorganisms are comparatively stable when used under field conditions. This study screened the optimal combination of biocontrol metabolites, referred to as TMB, composed of culture filtrates from certain isolates of Trichoderma asperellum 10264, Bacillus subtilis S4-4-10, and Metarhizium anisopliae 3.11962 (1:4:1 (v/v)). RNA-seq analysis and transmission electron microscope observations were carried out to identify the major functions of the most effective culture filtrates against Magnaporthe oryzae (the pathogen causing rice blast disease) and Chilo suppressalis (an insect pest in rice cultivation). TMB was found to disrupt the midgut subcellular structure of C. suppressalis larvae and inhibit the expression of genes related to immunity, membrane components, protein synthesis, and other functions in C. suppressalis larvae and M. oryzae, thereby interfering with their normal growth, reproduction, and infection potential in rice. In addition, TMB was also able to promote rice growth and trigger host defense responses against infections by the target pests and pathogens. In summary, TMB generated different inhibitory activities against multiple targets in C. suppressalis and M. oryzae and induced plant immunity in rice. Therefore, it can be used as a new environmentally friendly agent or alternative to control rice pests and diseases.
Orosanga japonica (Melichar, 1898) (Hemiptera: Ricaniidae) is an important pest in the Black Sea Region in Türkiye. Despite the use of various methods and microbial factors from different sources to … Orosanga japonica (Melichar, 1898) (Hemiptera: Ricaniidae) is an important pest in the Black Sea Region in Türkiye. Despite the use of various methods and microbial factors from different sources to control this pest until recently, several pathogens have been detected. Entomopathogenic fungi are important microbial agents in pest control. In the present study, we isolated eighteen fungal strains from nymphs and adults of O. japonica with fungal infection collected in Rize, Trabzon and Artvin provinces of Türkiye in 2021-2022. According to morphological and molecular characterization based on internal transcribed spacer (ITS) sequences, all strains were identified as Beauveria bassiana (Bals.-Criv.) Vuill. (Ascomycotina: Hypocreales) (OJ1-OJ18). A screening test at 1 × 107 conidia/ml revealed that all the strains caused 75–100% mortality in nymphs and adults after 7 days. Further experiments were performed with the three most effective strains, all belonging to B. bassiana (OJ3, OJ7 and OJ15). The dose‒response tests of the three fungal strains were carried out on O. japonica nymphs and adults at concentrations of 1 × 104–8 conidia/ml. As a result of the concentration-response, the B. bassiana OJ3, OJ7 and OJ15 strains presented mortality rates of 100, 98.84 and 100%, respectively, at the highest dose (109 conidia/ml) on the 10th day, and the calculated LC50 values of OJ3, OJ7 and OJ15 were determined to be 1 × 104, 1.4 × 104 and 0.3 × 103 conidia/ml against nymphs and 1.6 × 104, 1.4 × 104 and 0.4 × 103 conidia/ml against adults, respectively. The presence of B. bassiana detected natural infections and the efficacy trials conducted in the laboratory revealed that B. bassiana has potential for use against O. japonica.
Entomopathogenic nematodes (EPNs) from the families Steinernematidae and Heterorhabditidae are biocontrol agents for the management of a wide range of insect pests. There is a tremendous opportunity for the discovery … Entomopathogenic nematodes (EPNs) from the families Steinernematidae and Heterorhabditidae are biocontrol agents for the management of a wide range of insect pests. There is a tremendous opportunity for the discovery of new nematode strains and species adapted to local environmental conditions and insect pests. Therefore, in the present study, efforts were made to isolate EPN strains/species from the Northwestern Himalayas (NWH) region. The soil samples were collected from different locations in Almora, Uttarakhand. The collected soil samples were baited with Corcyra cephalonica , and they were observed regularly for their mortality. EPNs were isolated from the cadaver using the white trap method. Based on morphological and morphometrical studies, Heterorhabditis sp. VLEPN01 shows a resemblance to the species of Heterorhabditis indica . Further identity was confirmed with molecular characterization using the rDNA ITS marker. The sequence of this native EPN isolate revealed 99.87% similarity with H. indica isolated from Mizoram, Northeastern India (MF618314). The efficacy of EPN was evaluated against major insect pests of the NWH region. The results showed that H. indica VLEPN01 is capable of causing 100% mortality in fall armyworm ( Spodoptera frugiperda ), white grub ( Anomala dimidiata ), tobacco caterpillar ( Spodoptera litura ), and pod borer ( Helicoverpa armigera ) under laboratory conditions. Hence, H. indica VLEPN01 can be utilized for field testing in the management of insect pests occurring in the NWH region.
A rhabditid Mesorhabditis franseni Fuchs, 1933 (Family, Mesorhabditidae) and pratylenchid nematode Pratylenchus goodeyi Sher and Allen, 1953 (Family, Pratylenchidae). They were illustrated by molecular aspects. All specimens of both genera … A rhabditid Mesorhabditis franseni Fuchs, 1933 (Family, Mesorhabditidae) and pratylenchid nematode Pratylenchus goodeyi Sher and Allen, 1953 (Family, Pratylenchidae). They were illustrated by molecular aspects. All specimens of both genera were cultured and reproduced for DNA extraction. M. franseni (IRQ.ZAh2 PP528819.1 isolate) was characterized. P. goodeyi (IRQ.ZAh5 PP535537 isolate) was also characterized. Selected specimens of these two species were molecularly characterized using the partial ITS-rRNA gene sequences. The ITS-rRNA sequence of IRQ.ZAh2 PP528819.1 isolate had a range of (98.62%-100%) sequence homology with ITS-rRNA sequence of M. franseni available in NCBI database. While, the ITS-rRNA sequence of IRQ.ZAh5 PP535537 isolate had (100%) sequence homology with ITS-rRNA sequence of P. goodeyi available in NCBI database. M. franseni (IRQ.ZAh2 PP528819.1 isolate) and P. goodeyi (IRQ.ZAh5 PP535537 isolate) are Iraq's first documented instance of these species.
Global food security poses a significant challenge in meeting the needs of a rapidly growing population. Currently, producers rely on chemical pesticides to overcome pest-related problems in crop husbandry. However, … Global food security poses a significant challenge in meeting the needs of a rapidly growing population. Currently, producers rely on chemical pesticides to overcome pest-related problems in crop husbandry. However, the extensive use of synthetic molecules results in environmental pollution, resistance development, residual toxicity, pest recurrence and negative impacts on human and animal health. The expanding worldwide population has generated a substantial need for agricultural goods in terms of both quality and quantity, leading to a notable rise in the application of agricultural chemicals, including chemical pesticides, to combat insect pests. As a result, the use of entomopathogens for biological control has emerged as a prominent choice among these options. Currently, farmers are using microbial biopesticide solutions to counteract the negative effects of specific insects on crops. Microbes present a sustainable and adaptable solution that can effectively combat harmful pests without causing significant economic damage while simultaneously improving the health and productivity of plants. In 2020, biopesticides held a 6 % share in the global pesticide industry, with projections indicating a twofold increase to approximately 15 % by 2031. The purpose of this review was to highlight the widely accessible endophytic entomopathogens and explore their potential as a substitute for chemical pesticides. The primary goal of using endophytic entomopathogens is to maintain an optimal level of production, improve environmental well-being, reduce pesticide use and conserve natural resources. Moreover, research is now being conducted to investigate further potential characteristics, particularly concentrating on effective and rapidly spreading endophytic entomopathogens. This paper presents an overview of the mechanisms of action and the resistance they provide against herbivore insects, along with their respective benefits and limitations.
Abstract White grub, Holotrichia serrata (Coleoptera: Scarabaeidae), is one of the most destructive pests of sugarcane in India. Though it is a major pest, its biology in sugarcane has not … Abstract White grub, Holotrichia serrata (Coleoptera: Scarabaeidae), is one of the most destructive pests of sugarcane in India. Though it is a major pest, its biology in sugarcane has not yet been studied in detail. It would be difficult to manage the pest without knowing its biology on the host plant. Hence, the biology of H. serrata was studied in sugarcane and its shoot powder‐based artificial diet under laboratory conditions. This is the first report on the biology of H. serrata in sugarcane and artificial diet. The artificial diet standardised in this study could support the pest to complete its life cycle successfully. In sugarcane shoot chips, the duration of egg, larval and pupal stages of male individuals was 10–12, 121–154 and 15–21 days, respectively. The corresponding values for females were 10–12, 120–151, and 15–20 days, respectively. The longevity of adult males and females was in the range of 57–78 and 68–81 days, respectively. Male and female insects completed their life cycle in 237.1 and 240.5 days, respectively. In artificial diet, they could complete their life cycle in 255.4 and 275.3 days, respectively. Sugarcane chips and the artificial diet have thus been proved to support the entire life cycle of H. serrata . In the present study, H. serrata passed through three instars to attain its pupal stage both in natural host and artificial diet. The mean head‐capsule widths were 2.72 + 0.09, 4.49 + 0.15 and 7.25 + 0.59 mm for the first through third instar grubs of cane‐reared population. The corresponding values for diet‐reared grubs were 2.74 + 0.20, 4.66 + 0.37 and 7.66 + 0.25 mm, respectively. The mean Dyar's ratios were 1.633 and 1.672 for cane‐reared and diet‐reared grubs, respectively. Excellent linearity between the instars and mean head‐capsule width, and frequency histogram with three prominent peaks confirm that the white grub has three instars. The findings of this study would have a significant impact in applied entomology. The use of sugarcane shoot chips or an artificial diet to rear the population under laboratory conditions is simple, cost‐effective and ensures the availability of grubs all through the years for the studies on applied agricultural entomology.
In this study, the effectiveness of wettable powder formulations containing entomopathogenic fungal spores of Beauveria bassiana Vuillemin (Hypocreales: Cordycipitaceae) and Metarhizium robertsii Sorokin (Hypocreales: Clavicipitaceae) was examined against major stored-product … In this study, the effectiveness of wettable powder formulations containing entomopathogenic fungal spores of Beauveria bassiana Vuillemin (Hypocreales: Cordycipitaceae) and Metarhizium robertsii Sorokin (Hypocreales: Clavicipitaceae) was examined against major stored-product pests in 2021 in Bioinsecticide Mass Production Laboratory of Plant Protection Department, Faculty of Agriculture, Kahramanmaraş Sütçü İmam University. Twelve formulations were developed: six of which were based on B. bassiana isolate 5-4 and the other six on M. robertsii isolate S3. The formulations were applied on both wheat and concrete surfaces at predetermined dosages. Bioassays were conducted using Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae) third-instar larvae, Rhyzopertha dominica (F.,1792) (Coleoptera: Bostrichidae) and Sitophilus oryzae L.,1763 (Coleoptera: Curculionidae) adults, under controlled conditions at 30±2°C, 65±5% relative humidity, and in darkness. When applied to wheat, all formulations exhibited high mortality rates against R. dominica and P. interpunctella, while showing limited efficacy against S. oryzae. Conversely, applications on concrete surfaces demonstrated higher efficacy to all pests, particularly against S. oryzae. Amongst the formulations, those containing B. bassiana outperformed M. robertsii-based formulations in terms of efficacy, both on concrete surfaces and wheat. The findings suggest that the developed formulations have significant potential as an effective alternative for pest management in empty storage facilities. Notably, surface applications provided superior results compared to applications directly on stored products.
Malaria remains a public health issue across the world. Different methods have been analyzed to achieve this disease's elimination, such as the vector control of Anopheles spp. Control strategies include … Malaria remains a public health issue across the world. Different methods have been analyzed to achieve this disease's elimination, such as the vector control of Anopheles spp. Control strategies include the use of different classes of insecticides, although the accelerated evolution of vectors resistant to them makes the development of alternative control methods necessary. Therefore, entomopathogenic fungi have been considered to be promising biopesticides, given that they are safe for human beings and the environment. This study aimed to evaluate the entomopathogenic activity of fungi collected in the Amazon Rainforest against adult female Anopheles aquasalis mosquitoes. Females were exposed to four different species of fungi and observed daily to evaluate their survival rate. Also, fungi species' behavior was analyzed through scanning electron microscopy (SEM). Those exposed to Trichoderma harzianum and Penicillium citrinum had their survival rate reduced. SEM confirmed the development of fungi on the mosquitoes after 48 h. The findings suggest that the entomopathogenic potential of the fungi used in this study should be considered, given the reduction in the survival rate of Anopheles aquasalis mosquitoes.
Societal Impact Statement Our meta‐analysis highlights the potential of entomopathogenic fungi (EPF) as sustainable alternatives to chemical pesticides and fertilisers. By promoting plant growth and reducing reliance on agrochemicals, EPF … Societal Impact Statement Our meta‐analysis highlights the potential of entomopathogenic fungi (EPF) as sustainable alternatives to chemical pesticides and fertilisers. By promoting plant growth and reducing reliance on agrochemicals, EPF can support healthier crops, minimise environmental contamination and improve profitability within food production systems. Optimising application methods and matching EPF to specific crops could accelerate adoption and enhance food security. However, further field research and knowledge‐sharing are needed to realise these benefits at scale. Overall, plant–EPF interactions offer a promising pathway towards resilient, environmentally friendly agriculture that benefits both people and the planet. Summary Entomopathogenic fungi (EPF) are widely used as biological agents against a range of insects. This meta‐analysis investigates the plantgrowth‐promoting effects of EPF and explores their potential as sustainable alternatives to pesticides and fertilisers. The goal is to determine if EPF generally promote plant growth and whether the fungal genus, inoculation method and dosage modulate these effects. We synthesised global data on experimental plant growth responses to EPF colonisation and performed a meta‐analysis on 90 studies including 797 paired observations of several important growth metrics. Overall, EPF had positive effects on growth with significant increases in plant height, leaf surface area, shoot dry mass and root mass. Beauveria and Metarhizium were the most commonly reported fungal genera. The inoculation method emerged as a significant moderator for shoot length, fresh mass and root dry mass with soil application showing the most consistent positive effects. Publication bias was detected, indicating a tendency to report positive results. Our results emphasise optimising the application method with compatible EPF for specific crop species or varieties and advocate for further field‐based research to understand real‐world applications
(1) Background: The larvae of Dioryctria sylvestrella typically bore into the shoots and cones of Pinus koraiensis, increasing tree breakage risk and reducing cone yield. (2) Methods: Five Beauveria bassiana … (1) Background: The larvae of Dioryctria sylvestrella typically bore into the shoots and cones of Pinus koraiensis, increasing tree breakage risk and reducing cone yield. (2) Methods: Five Beauveria bassiana strains were evaluated for virulence against fourth-instar larvae. And the levels of T-AOC and MDA in the larvae infected by each strain were measured. To assess larval responses to different strains, we measured the activities of six enzymes (SOD, CAT, POD, PPO, CarE, GST) and the levels of GSH and H2O2 in larvae treated with each strain. Additionally, the infection process of highly pathogenic B. bassiana in larvae was explored using scanning electron microscopy (SEM). (3) Results: Strain CGMCC3.2055 demonstrated the highest toxicity to larvae, achieving a cumulative corrected mortality of 80.56% on the 4th day and an LT50 of 3.248 days. The T-AOC of larvae treated with strain CGMCC3.2055 was inhibited within 48 h. The relative MDA content in this group was significantly higher than that in other strain-treated groups at 6, 12, and 24 h. In Bb01-treated larvae, H2O2 accumulation at 6 and 24 h post-infection was influenced by POD activity rather than GSH levels; in BbZ1-treated larvae, the activities of CAT and POD were upregulated at 6 and 36 h, while the activity of SOD was downregulated, but the content of H2O2 increased significantly, resulting in accumulation; in CFCC81428-treated larvae, a decline in T-AOC coincided with substantial H2O2 accumulation over 48 h, while a concomitant increase in GSH content bolstered tolerance to lethal oxidative damage; in CGMCC3.2055-treated larvae, H2O2 only accumulated significantly at 24 and 48 h, yet upregulated CAT and POD were insufficient to effectively scavenge the excess H2O2; and in bio-21738-treated larvae, SOD-driven dismutation generated substantial H2O2 from 12 to 48 h, leading to pronounced accumulation from 6 to 48 h, yet limited upregulation of POD (only at 6 and 12 h) and CAT (only at 12 and 48 h) were insufficient to mitigate H2O2 buildup. PPO activity was upregulated within 48 h in all treatment groups except for BbZ1, where no upregulation was observed at 12 and 48 h. GST activity was upregulated in all treatment groups except for CGMCC3.2055, where a downregulation was observed at 12 h post-infection. CarE activity was significantly upregulated within 48 h in both CFCC81428 and CGMCC3.2055 groups; in the Bb01 group, CarE was upregulated only at 6 and 48 h; in the BbZ1 group, CarE was downregulated only at 48 h; and in the bio-21738 group, CarE showed no upregulation at 24 and 48 h. Through SEM, the infection process of the strain CGMCC3.2055 on the surface of the larvae was further determined, which mainly included adhesion, the appearance of bud-like protrusions, the growth of germ tubes along the epidermis and penetration of the epidermis, as well as the colonization of the strain and its emergence from the surface of the larvae. (4) Conclusions: This study first screened the highly pathogenic B. bassiana strain CGMCC3.2055 by evaluating its virulence to larvae and post-infection T-AOC and MDA levels. It also clarified the strain's infection process and the larvae's immune responses to various strains.
Abstract Defensive secretions produced by certain hemipterans are known to deter natural enemies and play a crucial role in reducing microbial infections. In this study, we investigated the protective mechanisms … Abstract Defensive secretions produced by certain hemipterans are known to deter natural enemies and play a crucial role in reducing microbial infections. In this study, we investigated the protective mechanisms of the chinch bug Blissus pulchellus against entomopathogenic fungi and we explored the relationship between the major volatile compounds produced by B. pulchellus and their potential role in enhancing its resilience to disease. Both adults and nymphs exhibited low susceptibility to infection by various strains of Metarhizium anisopliae and Beauveria bassiana . The close and continuous contact of conidia with antimicrobial substances on the insect's integument significantly inhibited germination rates. Conidia washed from insects after 4 h of contact with their integument exhibited germination rates of less than 20% on culture media. Chemical analyses of body extracts from adults and nymphs revealed both qualitative and quantitative differences in their defensive compound profiles. Our findings suggest that the aldehydes are the primary compounds responsible for fungal inhibition, effectively protecting the insect from infection. Identifying fungal strains capable of overcoming the fungitoxic compounds produced by B. pulchellus is crucial for advancing mycopesticide development to manage chinch bug populations in pastures.
In this paper, we demonstrate the effectiveness of an entomopathogenic fungus, namely, Metarhizium to reduce environmental problems arising from the use of insecticides. Metarhizium species used in the article include … In this paper, we demonstrate the effectiveness of an entomopathogenic fungus, namely, Metarhizium to reduce environmental problems arising from the use of insecticides. Metarhizium species used in the article include M. anisopliae sensu stricto, M. anisopliae sensu lato, and M. pingshaense. The efficacy of them in controlling the spread of the brown planthopper (BPH) collected from three different regions of Thailand, including Phetchabun Province, Buri Ram Province and Phatthalung Province, was analyzed. Using actual data representing the daily mortality of BPH, we estimated the corrected mortality. In addition, we studied four candidate BPH survival functions, namely the Gompertz model, the Weibull model, the sigmoid model, and the log-logistic model, in order to achieve the best model fitting to the experimental data. As a result, most of the data was best fitted by the log-logistic model. We also used the susceptible infected model to determine the transmission rate from susceptible BPH to infected BPH. Finally, the lethal time formulas and the estimated values of time required for 50% and 90% mortality were obtained using the log-logistic survival and SI models. From the results, the obtained lethal times for both models have the same trends. It is worth noticing that the M. anisopliae sensu lato fungus gave the most effective results in destroying BPH based on the percentages of corrected mortality, lethal time values and transmission rate.
Abstract Akanthomyces lecanii is an entomopathogenic fungus, and spores of this fungus could be incorporated into films generated using cast film extrusion for biocontrol applications. However, the extrusion process involves … Abstract Akanthomyces lecanii is an entomopathogenic fungus, and spores of this fungus could be incorporated into films generated using cast film extrusion for biocontrol applications. However, the extrusion process involves high temperature processing (150°C) although this only lasts for a few minutes. The elevated temperature destroys spores, thereby eliminating functionality, unless the spores are protected from this heat. Initial experiments revealed that the heat tolerance of free A. lecanii spores to be 60°C. The spores were therefore encapsulated into beads prepared using a combination of Gelrite, cellulose and Cel-fine at different concentrations. The beads were freeze-dried and then immersed in hot glycerol for 2 minutes at a selected temperature within the range of 50–100°C. The results indicated that some combinations of encapsulating agents resulted in the spores retaining viability (plate counting) after heat treatment at 100°C. Beads stored at room temperature for one week showed a reduction in the upper temperature tolerance. This study revealed that the temperature tolerance of A. lecanii spores could be improved by 40°C by encapsulation in freeze-dried beads containing 2% Gelrite (purified gellum gum), 0.4% cellulose and 0.4% Cel-fine.
Entomopathogenic fungi are a group of fungi that infect and kill insects to obtain nutrients, thereby contributing to the natural regulation of insect populations. In recent years, they have been … Entomopathogenic fungi are a group of fungi that infect and kill insects to obtain nutrients, thereby contributing to the natural regulation of insect populations. In recent years, they have been increasingly utilized as biological control agents, particularly in response to the rising prevalence of pesticide-resistant pests in agricultural systems. Representative examples include Beauveria bassiana and Metarhizium anisopliae, which are regarded as natural enemies of pests in agroecosystems. Since the first report of Korean oak wilt disease in 2004, the disease has continuously spread across the country and causes severe damage to deciduous oak species, especially Quercus mongolica. Although many efforts have been made to effectively control the disease, including chemical treatments, the control efficacy was shown to be low, and given the environmental side effects arising from the use of insecticides, there has been a demand for alternative control strategies. Integrated Pest Management in forests promotes ecological sustainability by reducing chemical pesticide use, conserving biodiversity, and enhancing long-term forest health. In this study, to mitigate issues with disease management strategies, assessments were made on three entomopathogenic fungi, B. bassiana, M. anisopliae, and Purpureocillium lilacinum, as potential biological control agents against oak wilt disease and its insect vector, Platypus koryoensis. In this regard, we investigated the insecticidal efficacy and LT50 of each entomopathogenic fungus, and the results showed that all three entomopathogenic fungal strains exhibited fast insecticidal effects against the insect vector, P. koryoensis, with M. anisopliae showing the fastest action, recording a lethal time to 50% mortality (LT50) of 58.7 h. The spores of M. anisopliae were found to be sensitive to high temperatures, while demonstrating a relatively high germination rate under UV exposure and strong initial germination ability at low temperatures.
Abstract Background Endophytic fungi can colonize and live in plant tissues without causing disease or harming their host plants. Some related endophytic fungi can also act as entomopathogens. The diversity … Abstract Background Endophytic fungi can colonize and live in plant tissues without causing disease or harming their host plants. Some related endophytic fungi can also act as entomopathogens. The diversity and level of pathogenicity of endophytic fungi can be influenced by various factors, such as rice varieties and the location where they grow. Payo rice variety is one of the highest rice-producing areas in Jambi Province, Indonesia. There have been no reports of high brown plant hopper attacks on the Payo rice variety. This study aimed to determine the entomopathogenicity of endophytic fungi isolated from Payo rice varieties grown in Kerinci Regency, Indonesia. Result Based on the research, 62 isolates of endophytic fungi were successfully isolated from the roots, tillers, and leaves of the Payo rice variety. The highest colonization rate occurred in the leaves (57.00%) and the lowest in the roots (44.00%). An entomopathogenicity test was carried out on the 62 isolates obtained against Tenebrio molitor (Coleoptera: Tenebrionidae), and one control ( T. molitor without isolate application) was added as a comparison. All treatments were done, respectively, in four replications. There were 14 isolates classified as entomopathogenic, which caused mortality of T. molitor larvae in the range of 2.5–100%, but only isolates PYA31, PYB11, PYB 13, PYB23 caused mortality and mycosis up to 100%. Meanwhile, PYB31 and PYB53 caused low mortality and mycosis. The six isolates were then observed for their growth morphologically using a binocular microscope with 400 × magnification and identified molecularly using ITS Primer. The observations revealed that the potential endophytic fungal species as entomopathogens of the Payo variety were Beauveria bassiana (PYA 31, PYB 11, PYB13, PYB23) with DNA bands in the range of 543–546 bp, Trichoderma yunnanense (PYB 31) with DNA bands at 577 bp, and Aspergillus flavus (PYB53) with DNA bands at 573 bp. Conclusion Entomopathogenic fungi isolated from Payo rice variety were successfully identified as Beauveria bassiana, Trichoderma yunnanense, and Aspergillus flavus . Of the three species, B. bassiana was the isolate with the highest entomopathogenicity and mycosis ability (100%). Controlling brown plant hopper and other pest insects using this fungus in the future is considered a safe and environmentally friendly measure.
The fall armyworm (Spodoptera frugiperda) poses a problem for corn plants (Zea mays L.). The use of endophytic bacteria Bacillus sp. as an entomopathogen is expected to control the S. … The fall armyworm (Spodoptera frugiperda) poses a problem for corn plants (Zea mays L.). The use of endophytic bacteria Bacillus sp. as an entomopathogen is expected to control the S. frugiperda pest. This study aims to determine the effective concentration of the bacteria and the active compounds produced by Bacillus sp. strain Bth 22 in controlling S. frugiperda. The research was conducted from August to October 2024 at the Plant Health Laboratory of the Faculty of Agriculture, UPN "Veteran" East Java, and the Airlangga Research Hub in Surabaya. The study was designed using a completely randomized design (CRD) with bacterial concentration treatments of 0% (control), 10%, 15%, 20%, 25%, 30%, and 35%, repeated five times. Observational parameters included mortality rate, number of pupae and imago formed, as well as the mechanisms and compounds produced by Bacillus bacteria based on HPLC and FT-IR tests. The application of Bacillus sp. Bth-22 affected the mortality parameters, the number of pupae formed, and the number of imago formed. The Bacillus sp. Bth-22 bacteria produced metabolites in the form of hydrocarbon derivatives and amide group compounds, disrupting metabolism and digestion, leading to the mortality of S. frugiperda. Keywords: Entomopathogen, Metabolite compounds, Spodoptera frugiperda, Zea mays
Abstract BACKGROUND Basic helix–loop–helix (bHLH) transcription factors are critical regulators of differentiation, metabolism, and environmental response in eukaryotes. However, their functions in entomopathogenic fungus remain largely unexplored. RESULTS In this … Abstract BACKGROUND Basic helix–loop–helix (bHLH) transcription factors are critical regulators of differentiation, metabolism, and environmental response in eukaryotes. However, their functions in entomopathogenic fungus remain largely unexplored. RESULTS In this study, we identified and characterized the bHLH transcription factor MrBHLH1 in the model entomopathogenic fungus Metarhizium robertsii . Localization studies revealed that MrBHLH1 is predominantly found in the nuclei of both conidia and hyphae. The ΔMrbHLH1 mutant exhibited significant impairments in vegetative growth and conidial production, showing reductions of 63.01% and 63.95%, respectively, compared to the wild‐type (WT) strain on potato dextrose agar. Interestingly, ΔMrbHLH1 demonstrated increased resistance to various abiotic stresses, including ultraviolet (UV) irradiation, thermal, oxidative, osmotic, and cell wall integrity stresses, relative to WT. Furthermore, ΔMrbHLH1 displayed enhanced virulence, evidenced by a 19.3% reduction in median lethal time (LT 50 , in days) compared to WT, which was associated with accelerated appressoria formation, increased conidial adhesion and hydrophobicity, and improved cuticle penetration ability. Chromatin immunoprecipitation sequencing analysis revealed that MrBHLH1 regulates a set of target genes significantly enriched in the MAPK signaling pathway and autophagy processes. CONCLUSION This study establishes MrBHLH1 as a pivotal regulator in M. robertsii , orchestrating a balance between growth, stress adaptation, and pathogenicity. These findings enhance our understanding of the functional roles of bHLH transcription factors in entomopathogenic fungi and provide novel targets for the engineering of entomopathogens with improved biocontrol characteristics. © 2025 Society of Chemical Industry.
Introduction Cordyceps is a diverse genus of insect-pathogenic fungi, some of which have significant medicinal value. Methods The complete mitogenomes of six Cordyceps species ( C. cicadae , C. cocoonihabita … Introduction Cordyceps is a diverse genus of insect-pathogenic fungi, some of which have significant medicinal value. Methods The complete mitogenomes of six Cordyceps species ( C. cicadae , C. cocoonihabita , C. militaris , C. neopruinosa , C. pruinosa , and C. tenuipes ) were sequenced, assembled, and annotated in this study. Additionally, the previously published mitogenome of C. blackwelliae was also included for comparative analysis. Results The mitogenomes of these seven Cordyceps species are circular DNA molecules ranging length from 29,929 to 51,692bp, containing 15 protein-coding genes (PCGs), two rRNAs, and 25–27 tRNAs, as well as four to 21 open reading frames (ORFs). The rps3 gene appears to be under relaxed selection pressure across Cordyceps species. The non-conserved PCGs, such as homing endonucleases and proteins of unknown functions, show dynamic evolutionary patterns, highlighting the genetic diversity among the species. Introns, recognized as key contributors to mitogenome size variation, frequently undergo gain and loss events, further contributing to genomic diversity. The comparative analysis revealed both conserved and variable elements within the mitogenomes of the seven Cordyceps species. Phylogenetic analysis using 14 PCGs generated a well-supported topology that clarified the evolutionary relationships among Cordyceps species. Discussion In conclusion, this study provides valuable insights into the conservatism and variability of mitogenomes within the genus Cordyceps , enhancing our understanding of their origin, evolution, and genetic diversity.
Insect pests cause substantial yield losses in agriculture, prompting widespread use of chemical pesticides that threaten environmental and human health. Biological control using Beauveria bassiana offers a sustainable alternative, but … Insect pests cause substantial yield losses in agriculture, prompting widespread use of chemical pesticides that threaten environmental and human health. Biological control using Beauveria bassiana offers a sustainable alternative, but its efficacy is often limited by environmental stresses and formulation challenges. Encapsulating B. bassiana conidia with biopolymers helps protect the fungus from environmental stresses and improves shelf life by acting as a physical barrier. This study evaluated the compatibility of biopolymers, chitosan (0.1 %, 0.25 %, 0.5%, 1 % and 2.5 %) and lignosulphonate (1 %, 2.5 %, 5 %, 7.5 % and 10 %) with B. bassiana by assessing mycelial growth, spore production and virulence against Spodoptera litura larvae. Low chitosan concentrations (0.1–0.5 %) maintained high radial growth (up to 99.60 %), sporulation (2.00 × 10⁸ spores/mL) and larval mortality (88.33 %). However, at the highest concentration (2.5 %), chitosan significantly reduced B. bassiana performance, with radial mycelial growth declining to 90.21%, spore production dropping to 1.33 × 10⁸ spores/mL and larval mortality decreasing to 75.00 %. Lignosulphonate demonstrated superior compatibility, with mycelial growth above 98.8 % and larval mortality above 85 % at all concentrations. The control (without any added biopolymers) achieved 100 % mycelial growth, 2.00 × 10⁸ spores/mL and 91.67 % larval mortality. These results highlight lignosulphonate and low-dose chitosan as promising encapsulating agents for stable, effective B. bassiana formulations.
Abstract Entomopathogenic nematodes (EPNs) are emerging as effective biological control agents, offering an eco-friendly alternative to conventional chemical insecticides. Their efficacy stems from a mutualistic association with symbiotic bacteria, which … Abstract Entomopathogenic nematodes (EPNs) are emerging as effective biological control agents, offering an eco-friendly alternative to conventional chemical insecticides. Their efficacy stems from a mutualistic association with symbiotic bacteria, which enhances their pathogenicity and aids in efficient insect host exploitation. Various application techniques, including advanced horticultural equipment and formulation innovations, have been developed to optimize their use in agricultural systems. However, the effectiveness and persistence of EPNs are influenced by several factors, such as environmental conditions, biotic interactions, and host specificity. Despite their potential, broader adoption is constrained by challenges like high production costs, short shelf life, and susceptibility to adverse environmental conditions. To address these limitations, advancements in formulation – such as encapsulated nematodes and water-dispersible granules – have been explored to enhance storage stability and field performance. Genetic improvements, including extending the longevity of infective juveniles, improving symbiotic bacterial retention, and increasing resistance to environmental stressors, are pivotal in boosting their efficiency. Additionally, genomic research is crucial for identifying genetic determinants associated with key adaptive traits, enabling the selection or development of robust EPN strains suited to diverse climatic conditions. The successful integration of EPNs into pest management programs relies on a comprehensive understanding of their biology, ecological interactions, and environmental adaptability. Strengthening their role in integrated pest management (IPM) can substantially reduce dependence on chemical insecticides, promoting sustainable agriculture while maintaining ecological equilibrium.
Soil-dwelling insects play indispensable roles in regulating soil health, nutrient cycling, plant productivity, and ecological stability within agroecosystems. As integral components of the soil food web, these organisms function as … Soil-dwelling insects play indispensable roles in regulating soil health, nutrient cycling, plant productivity, and ecological stability within agroecosystems. As integral components of the soil food web, these organisms function as decomposers, herbivores, predators, mutualists, and bioindicators, facilitating organic matter breakdown, microbial regulation, and natural pest suppression. Their habitat preferences, vertical stratification, and functional niches are governed by soil moisture, texture, organic content, and vegetation diversity. Through litter fragmentation and bioturbation, insects like termites, beetles, and ants enhance soil aggregation, aeration, and nutrient mobilization, directly influencing crop health and yield. Interactions with microbes, nematodes, and rhizosphere communities further extend their ecological relevance, promoting microbial diversity and inducing plant defence pathways. Anthropogenic pressures such as tillage, pesticide application, habitat loss, and climate-induced shifts in temperature and precipitation regimes significantly alter their diversity, abundance, and functionality. Invasive soil insects and changing geographical distributions exacerbate pest risks and ecological imbalances. Conservation agriculture practices, agroecological interventions, habitat engineering, and the use of insect-based biofertilizers and biocontrol agents offer sustainable pathways to enhance beneficial soil insect functions. Molecular tools like DNA metabarcoding and soil metagenomics are advancing the resolution and scope of insect diversity assessments, while long-term multi-scalar research remains crucial for understanding their systemic impacts. Soil insects also exhibit strong potential as ecological indicators of land degradation, pollution, and agricultural sustainability due to their sensitivity to environmental stressors and ecosystem alterations. Integrating soil entomology into modern agricultural frameworks and policy planning is critical for developing resilient and productive agroecosystems under the pressures of intensification and climate change.
The excessive use of synthetic pesticides in farming has raised serious concerns about environmental damage and health risks. As a safer and sustainable option, Beauveria bassiana, a naturally occurring fungus … The excessive use of synthetic pesticides in farming has raised serious concerns about environmental damage and health risks. As a safer and sustainable option, Beauveria bassiana, a naturally occurring fungus found in soil, has gained attention for its ability to control various insect pests. This fungus infects insects by attaching to the exoskeleton, penetrating their defences, and growing inside until the insect dies. Studies have shown its effectiveness against major pests such as Callosobruchus maculatus, Tuta absoluta, and Macrosiphum rosae, making it a valuable biological control agent. Its broad host range and eco-friendly nature allow it to fit well within Integrated Pest Management (IPM) systems, reducing the reliance on harmful chemicals. Additionally, advancements like combining B.bassiana with additives such as kaolin have improved its efficiency in real-world conditions. While enhancing its pest-killing ability through genetic modifications shows promise, it’s also important to maintain its natural resilience. Overall, B. bassiana provides long-term pest control, supports sustainable farming practices, and offers a reliable alternative to chemical pesticides, contributing to safer agriculture and environmental conservation.
Background: Ticks are significant vectors of various pathogens affecting humans and livestock, necessitating effective control strategies. The widespread use of chemical acaricides has led to resistance development and environmental concerns, … Background: Ticks are significant vectors of various pathogens affecting humans and livestock, necessitating effective control strategies. The widespread use of chemical acaricides has led to resistance development and environmental concerns, highlighting the need for sustainable alternatives. Entomopathogenic fungi (EPF), particularly Metarhizium anisopliae and Beauveria bassiana, have emerged as promising biocontrol agents due to their pathogenicity against arthropods. This study evaluates the efficacy of these fungi in controlling tick populations under laboratory and field conditions. Methods: Fungal isolates of M. anisopliae and B. bassiana were cultured and applied to adult and nymphal ticks using direct immersion and topical application methods. Tick mortality was monitored over 14 days, and lethal time 50% (LT50) and lethal concentration 50% (LC50) values were determined using probit analysis. Environmental stability assays assessed conidial viability under different temperature and ultraviolet (UV) exposure conditions. A field trial was conducted to evaluate fungal efficacy in reducing tick populations in a natural setting. Results: Both M. anisopliae and B. bassiana induced significant mortality in ticks, with M. anisopliae exhibiting slightly higher virulence. LT50 values were 5.8 ± 0.4 days for M. anisopliae and 6.9 ± 0.5 days for B. bassiana. Conidial viability declined under high temperatures and prolonged UV exposure, but fungal application in shaded areas improved efficacy. The field trial showed a 67.3% reduction in tick populations after fungal treatment (p < 0.001). Discussion: These findings demonstrate the potential of EPF as effective biocontrol agents for tick management. While environmental factors influence fungal persistence, protective formulations and targeted application strategies could enhance field performance. Integrating EPF with other control measures may provide a sustainable approach to tick population suppression.
Abstract Aims The challenges of mass production and environmental stress affect the application of entomopathogenic fungi (EPF). Therefore, this study attempts to develop a procedure based on EPF molecular markers … Abstract Aims The challenges of mass production and environmental stress affect the application of entomopathogenic fungi (EPF). Therefore, this study attempts to develop a procedure based on EPF molecular markers to facilitate the EP selection. Methods and Results In this study, three Beauveria bassiana isolates and six Metarhizium spp., were evaluated for conidial production and environmental stress tolerances. The expression levels of six phenotypic related genes were analyzed to assess correlations with conidial production and stress tolerance in two phenotypic different isolates of B. bassiana and Metarhizium spp. In B. bassiana isolates, both slt2 and catA showed strong correlations with conidial production and thermotolerance. Additionally, slt2 and hog1 were associated with osmotic stress tolerance and oxidative stress tolerance, respectively. However, the correlation between phenotypes and gene expression trends was not consistent in Metarhizium spp. Further validation using three M. pinghaense isolates indicated that hog1 was strongly correlated with conidial production, while mbf1, slt2 and cag8 were associated with thermotolerance, oxidative stress tolerance, and osmotic stress tolerance, respectively. Conclusions These findings suggest the existence of intra-species conservation in phenotypic mechanisms and offer a strategy for the rapid selection of promising EPF strains.
&lt;p&gt;Entomopathogenic fungi are potential candidates for ecofriendly pest-management. These fungi with botanical extracts can improve control over insect pests of economical crops. This study assessed the biocompatibility between four fungi … &lt;p&gt;Entomopathogenic fungi are potential candidates for ecofriendly pest-management. These fungi with botanical extracts can improve control over insect pests of economical crops. This study assessed the biocompatibility between four fungi (&lt;em&gt;Aspergillus flavus&lt;/em&gt;, &lt;em&gt;Aspergillus oryzae&lt;/em&gt;, &lt;em&gt;Metarhizium flavoviride&lt;/em&gt;, and &lt;em&gt;Trichoderma&lt;/em&gt; &lt;em&gt;hamatum&lt;/em&gt;) and four aqueous plant leaf extracts (&lt;em&gt;Azadirachta indica&lt;/em&gt;, &lt;em&gt;Eucalyptus camaldulensis&lt;/em&gt;, &lt;em&gt;Melia azedarach&lt;/em&gt;, and &lt;em&gt;Ocimum sanctum&lt;/em&gt;). The fungal strain pure cultures were procured from the Fungal Culture Bank, University of the Punjab, Lahore. Leaf extracts were employed at 0.25% to 1% concentrations, whereas fungal inocula were maintained at 1 × 10&lt;sup&gt;8&lt;/sup&gt; conidia/ml. Fungal dry mycelial weight (DMW), colonial growth (CG), and conidial density (CD) were recorded on PDB and PDA media with leaf extracts. Compatibility was calculated based on DMW, CG, and CD results. &lt;em&gt;Aspergillus flavus&lt;/em&gt; was highly compatible with 0.25% to 1% &lt;em&gt;A. indica&lt;/em&gt; leaf extract. &lt;em&gt;Aspergillus oryzae&lt;/em&gt; was compatible with 0.5% to 1% &lt;em&gt;E. Camaldulensis&lt;/em&gt; and 0.25% &lt;em&gt;M. azedarach&lt;/em&gt; leaf extracts. &lt;em&gt;Metarhizium flavoviride&lt;/em&gt; was compatible with 0.5% to 1% &lt;em&gt;E. Camaldulensis&lt;/em&gt; and 1% &lt;em&gt;M. azedarach&lt;/em&gt; leaf extracts. &lt;em&gt;Trichoderma hamatum&lt;/em&gt; shared high compatibility with most concentrations of plant extracts and emerged as the most promising strain. These findings promote fungi-plant extract combination as an ecofriendly pest-management alternative.&lt;/p&gt;