Use Of Entomopathogenic Fungi Research Articles

Discovery of Novel Entomopathogenic Fungi for Mosquito-Borne Disease Control.

The increased application of chemical control programs has led to the emergence and spread of insecticide resistance in mosquitoes. Novel environmentally safe control strategies are currently needed for the control of disease vectors. The use of entomopathogenic fungi could be a suitable alternative to chemical insecticides. Currently, Beauveria spp. and Metarhizium spp. are the most widely used entomopathogenic fungi for mosquito control, but increasing the arsenal with additional fungi is necessary to mitigate the emergence of resistance. Entomopathogenic fungi are distributed in a wide range of habitats. We have performed a comprehensive screen for candidate mosquitocidal fungi from diverse outdoor environments in Maryland and Puerto Rico. An initial screening of 22 fungi involving exposure of adult Anopheles gambiae to 2-weeks-old fungal cultures identified five potent pathogenic fungi, one of which is unidentified and the remaining four belonging to the three genera Galactomyces sp., Isaria sp. and Mucor sp. These fungi were then screened against Aedes aegypti, revealing Isaria sp. as a potent mosquito killer. The entomopathogenic effects were confirmed through spore-dipping assays. We also probed further into the killing mechanisms of these fungi and investigated whether the mosquitocidal activities were the result of potential toxic fungus-produced metabolites. Preliminary assays involving the exposure of mosquitoes to sterile filtered fungal liquid cultures showed that Galactomyces sp., Isaria sp. and the unidentified isolate 1 were the strongest producers of factors showing lethality against An. gambiae. We have identified five fungi that was pathogenic for An. gambiae and one for Ae. aegypti, among these fungi, four of them (two strains of Galactomyces sp., Mucor sp., and the unidentified isolate 1) have never previously been described as lethal to insects. Further characterization of these entomopathogenic fungi and their metabolites needs to be done to confirm their potential use in biologic control against mosquitoes.

Entomopathogenicity of fungi in combination with Ricinus communis extract for the control of Aleurocanthus woglumi

AbstractCitrus is among the most important crops in the world, and has suffered losses of up to 80% due to the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae). The combined use of entomopathogenic fungi and plant extracts is a sustainable alternative to control this pest. The objectives of this study were to select entomopathogenic fungi to control A. woglumi and verify the insecticidal effect of the combined use of the selected fungi and aqueous extracts of castor bean leaves, Ricinus communis L. (Euphorbiaceae). Twenty fungal isolates obtained from field‐collected dead A. woglumi were identified and tested against the insect. Eight were identified as belonging to Fusarium incarnatum‐equiseti species complex, nine to Fusarium fujikuroi species complex, two to Cordyceps javanica (Bally) Kepler, B. Shrestha & Spatafora, and one to genus Akanthomyces. The five isolates that caused the maximum confirmed mortality were tested for compatibility with aqueous castor bean extract at 5, 10, and 20% (wt/vol) concentrations. Qualitative phytochemical analysis showed the presence of alkaloids, glycoside flavonoids, saponins, and tannins in the castor bean extract. Most of the isolates studied caused high confirmed mortality of citrus blackfly. In the compatibility tests, Fusarium volatile Al‐Hatmi, Sand.‐Den., SA Ahmed & de Hoog and Fusarium proliferatum (Matsush.) Nirenberg ex Gerlach & Nirenberg combined with the 5% aqueous extract were the most suitable for testing against A. woglumi. Additive interactions were observed for the combined control agents. The highest value of confirmed mortality (98.2%) was observed for the combination of 5% aqueous castor bean extract and F. volatile (URM 8051), the efficacy of which should be confirmed by field tests.

Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity.

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

Arthropod diversity and corn stem borer Ostrinia furnacalis Guenee population in corn endophytes

Corn (Zea mays L.) is a strategic commodity that plays an important role in the development of agriculture and the Indonesian economy because corn has a multipurpose function that can be used for food and feed purposes. Obstacles in corn cultivation that cause low corn productivity include the attack of plant pests. The use of entomopathogenic fungi as endophytes is an alternative to chemical insecticides but can also be used to decrease the use of fertilizers. The research has been carried out at the Department of Food Crops and Horticulture Agriculture, Bontomarannu District, Gowa Regency, South Sulawesi, and the Laboratorium of Plant Pests and Diseases, Faculty of Agriculture, Hasanuddin University. Observation of larvae population of O. furnacalis was started when the plant was 35 days after planting (DAP) by observing the presence of grinding marks on the leaves and stalks of corn. The larvae found in the field are reared in the laboratory. Arthropod exploration in the field used 4 methods, namely visual observation, pitfall traps, yellow traps and using nets. The results obtained in this study were the arthropods found in the land of endophytic corn using the pitfall trap method, found as many as 48 insects. Using a net, 150 insects were found. Using the yellow trap, 243 insects were found and with visual observation found as many as 95 insects. The number of larvae of O. furnacalis infected with the fungus B. bassiana in corn female parents were 20 with an infection percentage of 83.3% and 11 male parents with an infection percentage of 91.7%.

Effects of entomopathogenic fungi on durum wheat nutrition and growth in the field

Entomopathogenic fungi (EF), which are widely used as biological insecticides, have been shown to colonize a wide range of plants influencing their performance. Also, recent studies under controlled conditions have revealed that EF can additionally act as plant growth promoters and nutritional enhancers. In this work, we examined the effects of the EF species Beauveria bassiana and Metarhizium brunneum on durum wheat (Triticum durum L.) plants grown on calcareous Vertisols in two field experiments spanning two consecutive seasons. The fungi were either directly applied to the soil (2015–2016) or used for seed dressing (2016–2017). With the soil application treatment, neither fungus was detected in soil 30 days after sowing (DAS) and only M. brunneum was present in plants (up to 16.6 % of them). With seed dressing, B. bassiana and M. brunneum colonized plant tissues in up to 16.6 and 4.1 %, respectively. Both fungi increased aerial dry matter in 5 of the 7 samplings conducted at early and mid-crop growth stages [viz., before Zadok’s stage 55 (heading)] in the two seasons, the increase being significant at the P < 0.10 level in 3 samplings and at P < 0.05 in 2 with B. bassiana. Direct application of B. bassiana to soil significantly increased total root length and root surface area at stem elongation stage, as well as root length and root surface area in the finest roots with both application methods. On the other hand, grain yield was significantly affected by neither treatment. Metarhizium brunneum increased P and Na grain nutrient concentrations, whereas B. bassiana applied by seed dressing decreased grain vitrosity. Overall, B. bassiana was more influential on wheat performance than M. brunneum. Our results encourage the use of EF for agriculture as they increased some wheat growth parameters in early and middle phenological stages.

Entomopathogenic Fungi for Tick Control in Cattle Livestock From Mexico.

Ticks are one of the main economic threats to the cattle industry worldwide affecting productivity, health and welfare. The need for alternative methods to control tick populations is prompted by the high prevalence of multiresistant tick strains to the main chemical acaricides and their ecological consequences. Biological control using entomopathogenic fungi (EPF) is one of the most promising alternative options. The objective of this paper is to review the use of EPF as an alternative control method against cattle ticks in Mexico. Metarhizium anisopliae sensu lato (s.l.) and Beauveria bassiana s.l. are the most studied EPF for the biological control of ticks in the laboratory and in the field, mainly against Rhipicephalus microplus; however, evaluations against other important cattle ticks such as Amblyomma mixtum and R. annulatus, are needed. A transdisciplinary approach is required to incorporate different types of tools, such as genomics, transcriptomics and proteomics in order to better understand the pathogenicity/virulence mechanism in EPF against ticks. Laboratory tests have demonstrated the EPF efficacy to control susceptible and resistant/multiresistant tick populations; whereas, field tests have shown satisfactory control efficiency of M. anisopliae s.l. against different stages of R. microplus when applied both on pasture and on cattle. Epidemiological aspects of ticks and environmental factors are considered as components that influence the acaricidal behavior of the EPF. Finally, considering all these aspects, some recommendations are proposed for the use of EPF in integrated control schemes for livestock ticks.

Could Gnomoniopsis castaneae Be Used as a Biological Control Agent against Insect Pests?

Gnomoniopsis castaneae is the cause of the chestnut brown rot but has been also regarded as an important mortality factor for the chestnut gall wasp Dryocosmus kuriphilus. The question to whether G. castaneae could serve as a natural biocontrol agent against insect pests is investigated in the present study. We used three serious insect pests as experimental model insects: Plodia interpuctella and Trogoderma granarium, which are important pests of stored products, and Myzus persicae, a cosmopolitan, serious pest of annual and perennial crop plants. Although chemical pesticides represent effective control means, they are also related to several environmental and health risks. In search for alternative pest management methods, scientific interest has been focused, inter alia, on the use of entomopathogenic fungi. While Isaria fumosorosea has long been recognized as an effective control agent against several pests, G.castaneae has been very little studied. The present study examined whether and to what extent G. castaneae and I. fumosorosea exhibit insecticidal activity against fourth-instar larvae of P. interpunctella and T. granarium and adults of M. persicae. Mortality was examined in interrelation with dosage and time exposure intervals. Both fungi exhibited pesticidal action. However, G. castaneae induced noteworthy mortality only at very high doses. In general, we concluded that G. castaneae failed to cause high insect pathogenicity at normal doses and may not be an efficient biocontrol agent compared with other entomopathogens. On the other hand, our study reiterates the pathogenic potential of I. fumosorosea. More studies are needed to further our insight into the potential of EF species as a component of IPM.

Beauveria bassiana PSUB01 simultaneously displays biocontrol activity against Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) and promotes plant growth in Chinese kale under hydroponic growing conditions

ABSTRACT The mustard aphid, Lipaphis erysimi, is a significant agricultural pest, responsible for yield losses in several vegetable crops. A desire to reduce insecticide applications in green house vegetable production systems has led to increasing use of entomopathogenic fungi to manage pests, including aphids. In this study, we evaluated the efficacy of the entomopathogenic fungus, Beauveria bassiana PSUB01, for the management of L. erysimi in Chinese kale grown hydroponically. Drenching roots and spraying foliage with B. bassiana PSUB01 conidial suspension were used as inoculation methods. Tested conidia concentrations of B. bassiana PSUB01 (108 and 109 conidia/ml) caused 87–89% mortality in L. erysimi after five days of application. The application of B. bassiana PSUB01 by root drenching colonised all treated parts (root, stem and leaf) with 64.0–96.0% colonisation (based on number of samples tested) in different part of tested plants during 7–21 days after inoculation. The application of B. bassiana PSUB01 on Chinese kale by either foliar spray or foliar spray + drenching of roots had reduced the fecundity of L. erysimi with very few progeny during 6–14 days of treatment. Also, application of B. bassiana PSUB01 by drenching of roots or by combination of foliar spray + drenching of roots enhanced plant growth parameters significantly except root length. These results suggest that B. bassiana PSUB01 could be included as part of an integrated pest management (IPM) plan for the management of L. erysimi under hydroponic production of Chinese kale and other vegetable crops.

Molecular identification of three entomopathogenic fungi infecting the brown plant hopper pest in Indonesia

BackgroundBrown plant hopper (Nilaparvata lugens Stal.) a very damaging pest to rice crops. One of the efforts to control it is the use of entomopathogenic fungi (EPF). Three fungal local isolates found in Indonesia were effective in controlling the brown plant hopper pest. This study aimed to molecularly identify the 3 fungal isolates. Molecular identification is very important to get the exact identity of these fungi. The accuracy of EPF identification will greatly determine the success of control. Molecular identification is based on a partial genetic analysis of the internal transcribed spacer (ITS) locus of ribosomal fungal DNA.ResultMorphology of the local isolates named J22 and J60 were identified as Paecilomyces sp., while the isolate J34 was identified as Beauveria sp. The results of molecular identification of the isolates J22 and J60 were identified as the fungi Lecanicillium saksenae and Simplicillium sp., while isolate J34 was identified as Myrothecium sp. The results of literature search showed that the 3 fungi have never been previously reported to infect the brown plant hopper.ConclusionIn Indonesia, 3 types of EPF, namely L. saksenae, Simplicillium sp., and Myrothecium sp., were found having the potential to control the brown plant hopper pest.

Current Advances in Biology, Distribution, and Management of Melanaphis sacchari (Zehntner)1 in México and United States of America

The sugarcane aphid, Melanaphis sacchari (Zehntner), is a major insect pest of sorghum (Sorghum bicolor (L.) Moench) in Mexico and United States of America. This review reports current advances for the biology of the aphid, crop damage, and sampling strategies to detect the pest. We focused on management through cultural control including resistant varieties, biological control with native parasitoids and predators and use of entomopathogenic fungi, legal control, and chemical control. Life stages of the aphid are nymph, nymphal alate, super nymph, and adult. Females have parthenogenetic reproduction and under adverse conditions, viviparous reproduction. Damage to the sorghum crop by feeding nymphs and adults causes stress to the plants and yield loss. To detect the pest, leaves should be sampled each week or yellow traps used with soapy water to monitor arrival of winged adults. Cultural practices recommended are destroying foci of infection and using established official planting dates and appropriate fertilization. Currently, the main control strategy is foliar application of insecticides. However, numerous species of predators, parasitoids, and entomopathogenic fungi affect sugarcane aphids in the USA and Mexico. The organisms could sustain control of the aphid, but few have been evaluated in the field. Studies of sorghum varieties in areas of México and the USA allowed identification of genotypes with resistance to sugarcane aphids. Considering sampling strategies, biology, and life cycle studies, search for an organism with potential for biological control of M. sacchari, and identification of sorghum genotypes with resistance to damage, it is possible to develop an integrated management strategy against sugarcane aphid. For future research, it is important to develop bioassays for monitoring resistance to insecticide, study interaction between factors that favor natural and induced control with natural enemies, and promote planting of sorghum genotypes with resistance.

Biological Control of the Raspberry Eriophyoid Mite Phyllocoptes gracilis Using Entomopathogenic Fungi

There is an urgent need to develop biological control methods against the eriophyoid mite, Phyllocoptes gracilis, which causes significant losses in organic raspberry production in Europe. The use of entomopathogenic fungi (EF) is a sustainable alternative to conventional chemical pesticides, reducing the risks of pesticide resistance and other negative environmental impacts of agriculture. The objective of this study was to assess the pathogenicity of three strains of EF, two of Beauveria bassiana and one of Metarhizium anisopliae, on P. gracilis under laboratory conditions. Fungal spore suspensions (1 × 107 spores per mL) were sprayed on detached leaves infested with P. gracilis. Treated mites were kept under controlled conditions (25 ± 3 °C, 72 ± 10% relative humidity and photoperiod of 16:8 (light/dark)) and mite mortality was assessed three, five and seven days after inoculation. At all three measurement points (days after inoculation), the mortality of P. gracilis was highest for B. bassiana strain BB 1.1 and M. anisopliae strain MA 10.1. Our data demonstrate that EFs are promising candidates for the development of biological control agents against P. gracilis in raspberry crops.

Control of Amazonian Leaf-Cutting Ants (Hymenoptera: Formicidae): A Multi-criteria Analysis

Leaf-cutting ants (Hymenoptera: Formicidae) are one of the main pests found in the Americas and they cause global economic losses worth several billions of dollars. While pesticides have been the most widely used control method, new management alternatives in a context of agroecological transition are now being considered. This study focuses on the leaf-cutting ants species found in the pan-Amazon region. As part of efforts to improve management of these pests, this multi-criteria analysis of control strategies covers a total of 691 experiments collected from 153 studies, and the control were evaluated as a function of their management efficacy, environmental and human health impacts, and their ease of application. Chemical control methods were effective but posed a danger to human health and the environment, whereas mechanical methods and integrated management were more sustainable but not always very effective. Some of the biocontrol methods were evaluated as effective and safe for the environment and human health, including the use of entomopathogenic fungi Beauveria bassiana (Bals.-Criv) Vuill. (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (Metschn.) Sorokïn (Hypocreales: Clavicipitaceae) in the form of bait or sprayed in the nest, or the application of plant mulch in the nest using Tithonia diversifolia (Hemsley) A. Gray (Asterales: Asteraceae) or Canavalia ensiformis L. DC. (Fabales: Fabaceae). Because of variations in the efficacy data between laboratory and field tests, we are in favor of evaluating these control methods during field studies with different leaf-cutting ant species and under different environmental conditions. These methods should adopt experimental arrangements that are appropriate for local socioeconomic conditions adapted for farmers.

Entomopathogenic Fungal Screening against Two Spotted Spider Mites, Tetranychus urticae Koch in Tomato and Broad Mite, Polyphagotarsonemus latus (Banks) in Chilli

Background: Entomopathogenic fungi are microorganisms that specifically infect and often kill insects and other arthropods. Most are non-pathogenic to plants and relatively non-toxic to humans and animals. Use of fungal entomopathogens can be an alternative to insecticides and could help in bio-intensive pest management. The current study aimed to study the pathogenicity of entomopathogenic fungal isolates against two Spotted Spider Mites, Tetranychus urticae Koch in tomato and broad Mite, Polyphagotarsonemus latus (Banks) in chilli. Methods: An extensive survey for the natural occurrence of entomopathogenic fungi on insects and mites was made in different agro climatic regions of Tamil Nadu during 2013 and 2014. Survey revealed the occurrence of two entomopathogenic fungi viz., Beauveria bassiana (Balsamo) Vuillemin and Metarhizium flavoviride Gams and Rozsypal var. minus. Laboratory experiment was conducted to evaluate the pathogenicity of fourteen isolates of Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii against Tetranychus urticae and Polyphagotarsonemus latus. Result: In opposition to T. urticae, the Beauveria bassiana isolate Bb 112 showed the highest toxicity of all the other isolates tested, with low LC50 value of 0.6 x106 spores ml-1 and LT50 of 92.60h. Against P. latus, Bb 112 had high virulence with low LC50 value of 0.3x106 spores ml-1 and LT50 value of 92.32h. Hence, there is potential for use of entomopathogenic fungi in the field conditions as an alternate control method in combating the insect pests and other arthropod pests since they are considered natural mortality agents and are environmentally safe.

Entomopathogenic fungal endophyte-mediated tritrophic interactions between Spodoptera littoralis and its parasitoid Hyposoter didymator

The use of entomopathogenic fungi for pest control is gaining increasing attention. These fungi act as contact biological insecticides but also via endophytic colonization of targeted crops. In addition, the joint use of entomopathogenic fungi and natural enemies hold potential in many pest control programs. Here, we evaluated in vitro and in planta multitrophic interactions among the endophytic fungus Metarhizium brunneum colonizing melon (Cucumis melo) plant, the parasitoid Hyposoter didymator and the pest Spodoptera littoralis. In all experiments, total mortality of S. littoralis larvae was significantly affected by the presence of the parasitoid; the treatments including the parasitoid achieved the highest mortality rates both in vitro and in planta. Simultaneous exposure to the fungus and the parasitoid did not significantly increase the total mortality of S. littoralis larvae than the parasitoid alone. The time between exposure to fungus and parasitoid attack did not affect S. littoralis mortality, nor parasitism (parasitoid) or infection rates (fungus). However, the parasitoid showed a significant preference for larvae fed on control plants (24.4% parasitism) compared with larvae fed on fungus-colonized plants (4.4%). A histological study of S. littoralis larvae simultaneously attacked by H. didymator and M. brunneum showed, for the first time, the coexistence of both agents within the same host; parasitoid larvae developed inside the host despite fungal colonization. This provides key information about intra-host interactions between two important biological control agents when used together for S. littoralis control.

Morphological and Molecular Identification of Entomopathogenic Fungi from Agricultural and Forestry Crops

Abstract A promising alternative for insect pest control in agriculture is the use of entomopathogenic fungi. The objectives of this work were to isolate and identify morphologically and molecularly strains of entomopathogenic fungi from crops of agricultural and forestry interest for the development of insect biocontrol technologies in Argentina. Three strains of Beauveria bassiana, and two strains of Metarhizium anisopliae were isolated and morphologically identified. Identity values greater than 99% with strains of B. bassiana and M. anisopliae were obtained in molecular databases. It was also confirmed by phylogenetic methods that the sequences obtained from these strains were positioned within the clade that contained the sequences of reference of B. bassiana and M. anisopliae respectively. These results deepen the knowledge of the mycobiota of Argentinian crops as a basis for the development of biotechnological products in the area of biological control.

ISSR markers to explore entomopathogenic fungi genetic diversity: Implications for biological control of tobacco pests

Tobacco is one of the major industrial crops cultivated worldwide. Chemical control is the main method employed to reduce damage by insect pests. The use of entomopathogenic fungi represents an alternative to replace insecticides. The search for effective strains in the field constitutes a first step when developing a formulation. The objective of this work was to study genetic differences among isolates of entomopathogenic fungi obtained from tobacco grown soils using ISSR markers. The pathogenicity of the strains towards Helicoverpa gelotopoeon and Diabrotica speciosa was also assessed in order to search for a relationship between virulence and genetic diversity. Nineteen isolates were identified according to morphological features and molecular techniques as Beauveria bassiana (11) and Purpureocillium lilacinum (8). The diversity tree generated by ISSR analysis showed a high diversity among the strains. The pathogenicity towards H. gelotopoeon and D. speciosa was assessed and the logistic models generated showed that B. bassiana isolates LPSc1215 and LPSc1364 were the most pathogenic against both insect pests tested. In the diversity tree, these strains were grouped in a same cluster with a similarity level of approximately 85%, indicating a possible relationship between virulence and the band pattern generated.

Characterization of entomopathogenic fungi as a natural biological control of American cockroaches (Periplaneta americana)

Abstract. Rosa E, Ekowati CN, Handayani TT, Ikhsanudin A, Apriliani F, Arifiyanto A. 2020. Characterization of entomopathogenic fungi as a natural biological control of American cockroaches (Periplaneta americana). Biodiversitas 21: 5276-5282. Eradicating cockroaches using chemical insecticides produces residues that contaminate the environment and promote insect resistance. Biological control has become an option for controlling cockroaches. The use of entomopathogenic fungi is one of them. The aim of this study was to obtain a fungal isolate that was effective at killing cockroaches. The result of entomopathogenic fungi isolation from cockroaches obtained 4 isolates, IK1, IK2, IK3 isolates were included in the Aspergillus genus while IK4 was Penicillium. Extracellular enzymes serve as screening materials for biocontrol candidates. IK1 and IK3 isolates showed higher chitinase activity than the other two isolates. The highest mortality of Periplaneta americana at nymphs stage was 60% achieved by the treatment of Aspergillus sp. IK3 with a concentration of 109 conidia/ mL. In adult stage cockroach the mortality was increased to 86%.

Avaliação de fungos no controle da mosca-das-frutas na preservação do mercado brasileiro de frutas

O controle biológico, com a utilização de fungos entomopatogênicos, tem sido umas das promissoras alternativas no controle de moscas-das-frutas. Este estudo teve como objetivo avaliar a patogenicidade dos fungos entomopatogênicos das espécies Metarhizium anisopliae (Metsch.) Sorok. e Beauveria bassiana (Bals.) em larvas de 2º e 3º instar, pupas e adultos da mosca-das-frutas Ceratitis capitata Wiedemann (Diptera: Tephritidae). O experimento foi conduzido nos Laboratórios de Zoologia de Invertebrados e de Fitopatologia do Centro de Ciências Agrárias, Universidade Federal da Paraíba, no município de Areia - PB. Neste estudo foram utilizados dois isolados, Metarhizium anisopliae IDCB425 e Beauveria bassiana IDCB66, em diferentes concentrações. Verificou-se que o potencial de infecção de ambos isolados é maior em larvas de 2º e 3º ínstares e de adultos de C. capitata, do que em pupas. A taxa de mortalidade de C. capitata aumenta à medida que as suspensões se tornam mais concentradas. O isolado de IDCB66 de B. bassiana é mais eficiente à C. capitata, que o isolado IDCB425 de M. anisopliae.

A Review of the Biology and Control of Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), with Special Reference to Biological Control Using Entomopathogenic Fungi

Simple SummaryThe whitefly, Bemisia tabaci, is considered one of the most destructive insect pests of vegetables and ornamental crops globally. Synthetic chemical pesticides are mainly used to control B. tabaci, however, their extensive usage has led to a series of detrimental concerns to human health and environmental contamination. It is therefore of significant interest to develop a safer and eco-friendly alternative for controlling B. tabaci. Here, we review the use of entomopathogenic fungi as a proven, biologically sustainable method to effectively control B. tabaci. The development of entomopathogenic fungi in an integrated pest management strategy against B. tabaci can reduce our reliance on chemical pesticides, and help us to secure food safety while preserving nature.Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), consists of genetically diverse species known to cause significant destruction in several crops around the world. Nymphs and adults of B. tabaci cause damage to plants during feeding, and they can act as a virus vector, thus causing significant yield loss to crops in the tropical and subtropical regions. Chemical pesticides are widely used to control B. tabaci due to their immediate action, but this approach has several drawbacks including food safety issues, insecticide resistance, environmental pollution, and the effect on non-target organisms. A biological control agent using entomopathogenic fungi (EPF) has therefore been developed as an alternative against the conventional use of chemical pesticides in an integrated pest management (IPM) system to effectively control B. tabaci. It is apparent from this review that species of hyphomycetes fungi are the most common EPF used to effectively control B. tabaci, with the second instar being the most susceptible stage of infection. Therefore, this review article focuses specifically on the control of B. tabaci with special emphasis on the use of EPF as biological control agents and their integration in IPM.

The aggregation pheromone phenylacetonitrile: Joint action with the entomopathogenic fungus Metarhizium anisopliae var. acridum and physiological and transcriptomic effects on Schistocerca gregaria nymphs

The combined use of entomopathogenic fungi and sublethal rate of chemical insecticides or other biological control agents have been proposed as an environmentally and sustainable strategy in the control of locust pests. In this paper, the quarter and the half of the recommended dose of Metarhizium anisopliae var. acridum (¼ and ½ Ma) and the aggregation pheromone (Phenylacetonitrile: PAN) were applied simultaneously and sequentially to Schistocerca gregaria fifth-instar nymphs. In addition, the physiological effects of PAN on locusts were assessed at the behavior, immune response, and biochemical level by evaluating for glutathione-S-transferase (GST), acetylcholinesterase inhibition (AChE), and malondialdehyde accumulation (MDA). Results showed that simultaneous application of PAN and the entomopathogenic fungus exhibited additive interaction. Synergistic interaction was also demonstrated when nymphs were exposed to PAN first, then treated with M. anisopliae var. acridum. Behavioral bioassay revealed that fifth-instar nymphs avoided the PAN odour and tended to remain away from the stimulus cup. In the choice assay, the pheromone significantly repelled the locusts at 2, 4, and 6 h of exposure which selected the PAN-free arena chamber. Moreover, treated nymphs become hyperactive and disoriented as evidenced by the cumulative distance travelled and the trajectory of locusts during the experiment. Immunological studies showed that PAN significantly decreased the differential haemocyte counts (prohemocytes and plasmatocytes) with a dose-response relationship. Data of biochemical analyzes showed that the PAN exposure reduced the activity of acetylcholinesterase and induced significantly the glutathione S-transferases and MDA concentration in the desert locust fifth-instar nymphs. Moreover, transcriptomic responses to the PAN exposure were evaluated using gene expression levels of CYP540 and GST. The transcript levels showed an up-regulation in GST expression level particularly in nymphs exposed for 4 and 6 h. A significant increase in CYP450 transcript level was also observed after 2 h of exposure, which decreased significantly after 4 and 6 h.