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Beauveria bassiana yeast phase on agar medium and its pathogenicity against Diatraea saccharalis (Lepidoptera: Crambidae) and Tetranychus urticae (Acari: Tetranychidae)
Abstract
Beauveria bassiana colonizes insect hosts initially through a yeast phase, which is common in some artificial liquid cultures, but not reported on artificial solid media. We describe a yeast-like phase for B. bassiana isolate 447 (ATCC 20872) on MacConkey agar and its virulence toward Diatraea saccharalis and Tetranychus urticae. The yeast-like cells of B. bassiana developed by budding from germinating conidia after 24-h incubation. Cells were typically 5-10 microm and fungal colonies were initially circular and mucoid, but later were covered with mycelia and conidia. Ability to produce yeast-like cells on MacConkey medium was relatively common among different B. bassiana isolates, but growth rate and timing of yeast-like cell production also varied. Metarhizium anisopliae and Paecilomyces spp. isolates did not grow as yeast-like cells on MacConkey medium. Yeast-like cells of B. bassiana 447 were more virulent against D. saccharalis than conidia when 10(7)cells/ml were used. At 10(8)cells/ml, the estimated mean survival time was 5.4 days for the yeast suspension and 7.7 days for the conidial suspension, perhaps due to faster germination. The LC(50) was also lower for yeast than conidial suspensions. Yeast-like cells and conidia had similar virulence against T. urticae; the average mortalities with yeast-like cells and conidia were, respectively, 42.8 and 45.0%, with 10(7)cells/ml, and 77.8 and 74.4%, with 10(8)cells/ml. The estimated mean survival times were 3.6 and 3.9 for yeast and conidial suspensions, respectively. The bioassay results demonstrate the yeast-like structures produced on MacConkey agar are effective as inoculum for B. bassiana applications against arthropod pests, and possibly superior to conidia against some species. Obtaining well-defined yeast phase cultures of entomopathogenic hyphomycetes may be an important step in studies of the biology and nutrition, pathogenesis, and the genetic manipulation of these fungi.
... Vuill. de ocorrência cosmopolita, vem sendo testado para o controle biológico de insetos-praga sob condições de laboratório e de campo, podendo colonizar artrópodes de diversas ordens (ATHAYDE et al., 2001;ALVES, et al., 2002;LUZ et al., 2004). Neste sentido, WRIGHT (1993) verificou o efeito de um micoinseticida à base de B. bassiana nas condições de campo no controle de adultos do bicudo-do-algodoeiro. ...
... Estudos de viabilidade, envolvendo a germinação de conídios, têm sido relacionados com o processo infeccioso e virulência dos fungos entomopatogênicos, visando a seleção de isolados que apresentem diferenças quanto a estes aspectos. A ausência de correlação entre a mortalidade de insetos e a taxa de germinação dos conídios de B. bassiana tem sido observada por diversos pesquisadores (LECUONA et al., 1996;FARIA et al., 1999;ALVES et al., 2002;DEVI et al., 2005) Esses estudos confirmam a facilidade de cultivo e viabilidade deste patógeno em meios artificiais, em diferentes condições de armazenamento, justificando, também, a importância desses parâmetros biológicos para B. bassiana (URM 3447) sobre o bicudo-doalgodoeiro. ...
... A taxa de crescimento radial das colônias de B. bassiana (URM-3447) não registrou diferença signifi-cativa aos 15 dias de crescimento, em meio BDA, cujas dimensões atingiram: 62,3, 61,0, 62,6 e 55,0 mm para o reisolado de ovos, larvas, adultos e o controle, respectivamente (Tabela 2). ALVES et al. (2002) estudaram o comportamento de crescimento de colônias de 15 isolados de B. bassiana em diferentes meios de cultura, como batata-dextroseágar (BDA), MacConkey-ágar + cristal violeta (BBL), sabouraud-dextrose-ágar (DAS) adicionados de cloreto de sódio (NaCl) em 0,25, 0,5, 1,2 e 3%. Para esses autores as colônias formaram-se distintamente entre 80 e 96h, a partir de 120h apresentaram aspecto mucoide, com estrutura micelial uniformemente distribuída sobre a superficície de ambos os meios, em placa de Petri. ...
Beauveria bassiana (Bals.) Vuill. (URM 3447) isolated from Castnia licus (Drury) and reisolated from eggs, larvae and adults of Anthonomus grandis (boll weevil), infected artificially was evaluated under various conditions (temperature: 27 ± 2º C, HR: 60 ± 10% and photophase: 14h). Estimation was made of the viability of B. bassiana (germination, colonial growth and conidiogenesis) in Potato-Dextrose-Agar (PDA) culture medium and virulence on the adult insect. Conidia in watery suspension with Tween 80 (0.05%), at various concentrations (0.62 x 10⁶; 0.24 x 10⁶ and 0.43 x 10⁶ conidia/mL) constituted the inoculum for the viability and virulence tests. Determination was made of the rate of germination to reisolated and no-reisolated fungus, 18h after the inoculation. Growth of the colonies and conidiogenesis were estimated in the intervals of 3, 6, 9, 12 and 15 days. Suspension of the conidia in concentrations caused mortality of 96.7, 83.4 and 91.1% in LT50 of 5.4, 5.9 and 5.3 days, respectively. The relative pathogen potency (RPP) indicated that the fungus was more aggressive after reisolation. It was verified that B. bassiana (URM-3447), reisolated from eggs, larvae and adults of the A. grandis, presented high viability of germination, colonial growth and conidiogenesis in PDA medium and high degree of virulence on the adult insect, being able to be used as an insect control agent.
KEY WORDS
Beauveria bassiana ; biological control; viability; Anthonomus grandis ; cotton
... Observations on vegetative growth and sporulation were transferred relative to the control (100) and the product's toxicity (T) values were calculated by following the formula adopted by Alves et al. (2002). Based on the results of compatibility study, groundnut oil was selected for carrying out the formulation of B. bassiana (MK918495). ...
... Therefore, resistance development due to the indiscriminate use of the acaricides and the concerns about public health and environmental issues has necessitated the researchers to unveil the alternative control strategies. Pathogenicity of entomopathogenic fungi viz., Beauveria bassiana, Hirsutella thompsonii and Lecanicillium lecanii against T. urticae were reported (Alves et al., 2002). Among the entomopathogenic fungi, the white muscardine fungus, B. bassiana, the green muscardine fungus, Metarhizium anisopliae and the white halo fungus, L. lecanii are in the forefront (Butt et al., 2001;Chavan et al., 2009). ...
... Prithiva et al. (2017) reported that oil formulation of B. bassiana recorded 45.86% reduction in population of Bemisia tabaci under microplot conditions. The better efficacy of formulation over crude suspension was reported by several authors (Agarwal et al., 2012;Alves et al., 2002;Batta, 2003). However, no significant difference was observed in the present investigation. ...
Bio efficacy of virulent isolate of entomopathogenic fungi, Beauveria bassiana (MK918495) was evaluated against two spotted spider mite, Tetranychus urticae on tuberose under pot culture condition at Insectary, Department of Agricultural Entomology, TNAU, Coimbatore. For effective working of any insect pathogen, it is mandatory to develop an effective formulation. Keeping this point in view, in the present study, compatibility of the fungal isolate with two different oils, viz., ground nut and sunflower were tested at different concentrations, viz., 1, 3, 5 and 10%. The results revealed that the groundnut oil was compatible with B. bassiana at all concentrations with respect to colony growth and spore yield compared to sunflower oil which was compatible only at one percent. Based on the results, oil in water and oil based formulations were prepared. At higher concentration of 10%, groundnut oil recorded the radial colony growth of 36.90 mm diameter and spore yield of 1.2 x 108 spores mL-1. Among the seven formulations (A-G) tested, formulation D which contained surfactant mixture having HLB value of 10.00 (53.33% Tween 80 and 46.67% Span 80) formed a better suspension with less flocculation layer and dispersion of conidia in spray fluid and was found to be better as it formed a good emulsion with water by mere shaking. Results of pot culture studies revealed that groundnut oil based fungal formulation was effective with a cumulative mean mite population reduction of 64.98% followed by crude fungal spore suspension (62.16%) and both were statistically on par with each other. Standard chemical check, Fenazaquin 10% EC @ 1.5 mL L-1 recorded significantly highest population reduction of mites (77.20%).
... Yeast-like growth was observed on MacConkey agar medium (BD Bioxon ® ) [29]. To determine the effect of inoculum size on the yeast-to-mycelium conversion, the culture medium was inoculated with 100, 500, 10 3 , 10 6 , or 10 7 spores using the spatulate method. ...
... The dimorphic fungus B. bassiana can develop yeast-like cells on MacConkey agar medium [29]. Fungal conidia (10 6 ) of the AS5 and AI2 strains were inoculated into the culture medium, and the yeast forms were observed after 48 h of growth. ...
Beauveria bassiana is a dimorphic and entomopathogenic fungus with different ecological roles in nature. In pathogenic fungi, yeast-to-mycelial conversion, which is controlled by environmental factors, is required for virulence. Here, we studied the effects of different stimuli on the morphology of two B. bassiana strains and compared the toxicities of culture filtrates. In addition, we explored the role of volatiles as quorum sensing-like signals during dimorphic transition. The killing assays in Caenorhabditis elegans (Nematoda: Rhabditidae) showed that strain AI2 isolated from a mycosed insect cadaver had higher toxicity than strain AS5 isolated from soil. Furthermore, AI2 showed earlier yeast-to-mycelial switching than AS5. However, an increase in inoculum size induced faster yeast-to-mycelium conversion in AS5 cells, suggesting a cell-density-dependent phenomenon. Gas chromatography-mass spectrometry (GC-MS) analyses showed that the fingerprint of the volatiles was strain-specific; however, during the morphological switching, an inverse relationship between the abundance of total terpenes and 3-methylbutanol was observed in both strains. Fungal exposure to 3-methylbutanol retarded the yeast-to-mycelium transition. Hence, this study provides evidence that volatile compounds are associated with critical events in the life cycle of B. bassiana.
... The susceptibility of B. oleae to entomopathogenic fungi has already been described. Konstantopoulou and Mazomenos (2005) , Ostrinia nubilalis (Safavi et al., 2010), Chilo partellus (Tefera and Pringle, 2003), Diatraea saccharalis (Alves et al., 2002), Strymon megarus (Inclán et al., 2008) and ...
... This entomopathogen has been isolated from several insect species, tested as biocontrol agent of numerous pests and commercially exploited as microbial pesticide (Shah and Pell, 2003;Faria and Wright, 2007;Zimmermann, 2007). Beauveria bassiana has been already described has caused of disease in a large number of lepidopteran species (Alves et al., 2002;Inclán et al., 2008;Maniania et al., 2011;Tefera and Pringle, 2003;Safavi et al., 2010;Wraight et al., 2010). ...
... However, the control did not differ from the other treatments evaluated. This result is in agreement with Tamai et al. (2002), in a study using Metarhizium anisopliae to control the mite Tetranychus urticae, found that 8 isolates (80%) presented values greater than 80% of corrected mortality on the fifth day, and 4 isolates presented mortalities greater than 90%. The results of the comparison of the number of mites in the different thirds of the pine trees in each of the evaluation periods are presented in Table 3. ...
Biological control is a growing branch in Brazil, and with it comes the need to obtain efficient enemies in the control of pests. The use of entomopathogens has expanded and with it comes the need to investigate their selectivity to non-target organisms. The present work was conducted in a pinecone (Annona squamosa L.) orchard with the objective of evaluating in which locations of the plant (lower, middle or upper third) and the effects of the entomopathogens: Beauveria bassiana, Metharhizium anisoplie and Bacillus thuringiensis on the predatory mite. Sixteen weekly applications were made between March and August 2017 with a constant pressure knapsack sprayer, nozzle type JA-2 with the jet directed at the entire plant. The treatments consisted of the use of three entomopathogenic biological products: Dipel, Beuaveria bassiana JCO and Metarhizium anisopliae JCO applied alone and in combination. Eight treatments were performed, as follows: T1-Spraying with M. anisopliae + phfos (Quimifol) + adhesive spreader (Agral), T2-Spraying with B. bassiana + phfos (Quimifol) + adhesive spreader (Agral), T3-Spraying with B. thruringiensis + phfos (Quimifol) + adhesive spreader (Agral), T4-Spraying with M. anisopliae + B. basisiana + phfos (Quimifol) + adhesive spreader (Agral), T5- Spraying with M. anisopliae + B. thruringiensis + phfos (Quimifol) + adhesive spreader (Agral), T6- Spraying with B. bassiana + B. thruringiensis + phfos (Quimifol) + adhesive spreader (Agral); T7- Spraying with M. anisopliae + B. bassiana + B. thruringiensis + phfos (Quimifol) + adhesive spreader (Agral) e T8-Testify, spraying with phfos (Quimifol) + adhesive spreader (Agral). The results indicate a preference of the Neoseiulus sp. mite for the middle third of the plant canopy. The results obtained indicated that the entomopathogens influenced the population of the Neoseiulus sp. mite until the sixth week after treatment, where the combination of Metarhizium anisopliae + Beauveria bassiana + Bacillus thuringiensis was the one that most negatively affected the population of the predatory mite Neoseiulus sp.
... También en este trabajo se evaluaron concentraciones de 5,5 x 10 4 a 5,5 x 10 8 conidios mL -1 y los valores de mortalidad obtenidos oscilaron entre 40 y 97,5 % de menor a mayor concentración, observados nueve días después de la inoculación del hongo. Alves et al., (2002) mencionan que en bioensayos realizados donde emplearon cepas de B. ...
Los barrenadores del tallo del género Diatraea son plagas importantes en el cultivo del maíz (Zea mays L.) debido a la dificultad que se tiene en su manejo, ya que éstas barrenan el tallo de la planta y es difícil de presenciar su daño. Los hongos entomopatógenos constituyen una opción para su manejo. Se evaluó la patogenicidad de dos cepas de Beauveria bassiana (BbP 001 y BbP 002) y una de Metarhizium rileyi (MrP 001) con el objetivo de seleccionar la más patogenica sobre larvas del cuarto instar de Diatraea grandiosella. Para determinar la patogenicidad de estas cepas, se empleó una concentración de 1x108 esporas mL-1 para lo cual se utilizó un diseño experimental completamente al azar con cuatro repeticiones, aplicando los tratamientos sobre trozos de tallos de maíz de 5 cm de longitud para posteriormente colocarles una larva a cada tallo (12 tallos y larvas por cada repetición, en total 48 larvas por tratamiento). La mortalidad se analizó mediante un ANOVA y una prueba de Tukey donde se observaron diferencias significativas (α = 0,05) entre los tratamientos, en el cual se presentó un porcentaje de mortalidad del 71%, 50%, 27% ocasionado por las cepas BbP 001, BbP 002, MrP 001 respectivamente. Se seleccionaron las cepas de B. bassiana para determinar la concentración letal 50 mediante un análisis PROBIT con el paquete estadístico SAS 9.0, se evaluaron las concentraciones (conidios mL-1) de 1x106, 1x107, 1x108, 4x108 y 7x108, la cepa más patogénica fue la BbP 001 presentando una CL 50 de 1.8x107 y una CL 90 de 1.3x109, mientras que la cepa BbP 002 fue menos patogénica con una CL 50 de 7.2x108 y una CL90 de 4.5x109. Con base en estos resultados se concluyó que existen hongos entomopatógenos presentes en forma natural que infectan a las larvas de D. grandioella que pueden ser aislados para emplearlos como fuente de control biológico.
... Wenzel et al. [24] also estimated the LC 50 of 1.58 × 10 7 conidia/mL for the Brazilian isolate IBCB 66. In another study, Alves et al. [25] obtained the LC50 of 4.8 × 10 6 conidia/mL for the Brazilian isolate B. bassiana 447 on the third stage larvae of D. saccharalis. However, it is not possible to compare the results obtained because of the methodological differences. ...
A native isolate of the Beauveria sp. fungus obtained from the Diatraea sp. larva was studied and identified as B. bassiana by analyses based on ribosomal internal transcribed spacer (ITS) sequences. The code given to the isolate was Bv062 and its insecticidal activity was evaluated on the second instar larvae of D. sacchara-lis, D. indigenella, D. tabernella and D. busckella, under laboratory conditions, producing mortality rates of 73.3, 83.3, 67.6 and 24.1 %, respectively. Subsequently, the activity of the fungus was evaluated on D. sac-charalis eggs. Egg mortality was of 82.2 % when spraying a conidial suspension adjusted to a concentration of 1 × 10 8 conidia/mL on the eggs. The mean lethal concentration (LC 50) was found to be 9.04 × 10 5 conidia/ mL and the lethal concentration ninety (LC 90) was of 2.07 × 10 7 conidia/mL on the second instar larvae of D. saccharalis. In-plant bioassays under semi-controlled conditions showed that fungus efficacy was above 50 % with the sporulation of dead larvae of 80 %, using concentrations between 1.0 × 10 7 and 5.0 × 10 7 conidia/ mL. Results demonstrated the high potential of B. bassiana Bv062 as a biocontrol agent for the development of a bio-insecticide to be used in the management of different species of the sugarcane stem borer complex. RESUMEN Identificación y caracterización de un aislamiento de Beauveria bassiana (Bals.) Vuill. con alto potencial para el control del barrenador del tallo de la caña de azúcar Diatraea spp. Se estudió un aislamiento na-tivo del hongo Beauveria sp. obtenido de una larva de Diatraea sp., el cual fue identificado molecularmente como B. bassiana mediante el análisis basado en las secuencias de la región espaciadora interna transcrita del ADN ribosomal (ITS). El aislamiento de B. bassiana fue codificado como Bv062 y se evaluó su actividad insecticida sobre larvas de segundo ínstar de D. saccharalis, D. indigenella, D. tabernella y D. busckella en condiciones de laboratorio, donde causó mortalidades del 73.3, 83.3, 67.6 y 24.1 % respectivamente. Posteriormente se evaluó la actividad del hongo sobre huevos de D. saccharalis y se encontró una mortalidad de huevos del 82.2 % al asperjarlos con una suspensión de conidios ajustada a una concentración de 1 × 10 8 conidios/mL. Se determinó una concentración letal media (CL 50) de 9.04 × 10 5 conidios/mL y una concentración letal noventa (CL 90) de 2.07 × 10 7 conidios/mL sobre larvas de segundo ínstar de D. saccharalis. Ensayos de actividad in planta en condiciones semicontroladas evidenciaron una eficacia del hongo superior al 50% con una esporulación de las larvas muertas superior al 80 %, al utilizar concentraciones entre 1.0 × 10 7 y 5.0 × 10 7 conidios/mL. Los resultados demostraron el alto potencial de B. bassiana Bv062 como agente de biocontrol para el futuro desarrollo de un bioinsecticida para el manejo de diferentes especies del complejo del barrenador del tallo de la caña de azúcar en este y otros cultivos hospederos.
... Agar pda Alves et al. (1996) Agar pda + benomil (10 μl/l) Oliveira et al. (2015) Agar pda + carbendazima (10 μl/l). Oliveira et al. (2015) Agar pda + extracto de levadura (1g /l) Fernandes et al. (2007) Medio de cultivo esporulación Alves et al. (2002) Agar agua ( • Los medios de cultivo enriquecidos, como el agar papa dextrosa, contienen todos los nutrientes necesarios y las condiciones ideales para el proceso de germinación, lo que puede generar una sobrevaloración del porcentaje de germinación. En el caso contrario, cuando se utilizan medios de cultivo basales como el agar agua, las condiciones son mínimas y similares a las que se pueden presentar en condiciones de campo. ...
Esta publicación tiene por objeto dar a conocer los estudios a nivel mundial y las experiencias de AGROSAVIA en control de calidad de bioinsumos agrícolas, con especial énfasis en parámetros microbiológicos, fisicoquímicos y biológicos de plaguicidas microbianos. El uso de microorganismos con interés comercial implica diferentes etapas y los controles son de gran importancia para asegurar la máxima eficacia en campo; sin embargo, actualmente existen muy pocos reportes en los que se detallen los métodos y los procesos de aseguramiento para obtener resultados confiables y veraces. En ese sentido, esta obra constituye un aporte que permitirá, además, mejorar e implementar metodologías de control de calidad rutinario de bioinsumos agrícolas.
... 35 In this study, the hydrophobic differences between the tested isolates may reflect variations in the ability to attach the insect body cuticle. 36 Conidial hydrophobicity evaluated in B. bassiana isolates against Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) 37 and M. anisopliae isolates against R. ferrugineus 38 has been used to determine the viability of the aerially-produced biocontrol agent conidia. 39,40 Although, our results indicate that conidia of Bb-0025 and Bb-0018 are more hydrophobic than those from M. anisopliae, they all have hydrophobicity higher than 75% indicating a potential interaction with the insect integument, as the first step toward pathogenesis, adhesion and inoculation processes on D. neivai. ...
BACKGROUND
The potential of Beauveria bassiana and Metarhizium anisopliae isolates obtained from naturally infected oil palm pests was evaluated to control Demotispa neivai as an alternative for organophosphate insecticide use in oil palm crops in Latin America. Two B. bassiana (Bb-0018 and Bb-0025) and two M. anisopliae (Ma-0002 and Ma-0003) isolates were tested against D. neivai adults for hydrophobicity, virulence, survival, adhesion to host cuticle, and mortality in semi-field conditions.
RESULTS
Concentration–mortality bioassays demonstrate that isolates had lethal effect on D. neivai adults with Bb-0025 (LC50 = 3.45 × 10⁷ conidia mL–1) and Bb-0018 (LC50 = 3.75 × 10⁷ conidia mL–1) being the most effective followed by Ma-0003 (LC50 = 3.38 × 10⁸ conidia mL–1) and Ma-0002 (5.33 × 10⁸ conidia mL–1). Adult survival was 99% without exposure to fungal isolates, decreasing to 21.65% in insects exposed to Ma-0002, 19.41% with Ma-0003, 20.13% with Bb-0018, and 0.17% with Bb-0025. Mortality of D. neivai adults caused by the entomopathogenic fungal isolates was similar in both laboratory and semi-field conditions. Also, vegetative growth of the entomopathogenic fungal isolates was found in infected D. neivai adults in the field.
CONCLUSION
Our data suggest that the tested entomopathogenic fungal isolates are effective against D. neivai with potential to be used as biological control agents contributing to decrease the use of chemical insecticides to control this oil palm pest.
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... Wekesa et al. (2005) reported the LC 50 values of 0.7 x 10 7 and 2.5x 10 7 conidia ml -1 for B. bassiana and M. anisopliae, respectively against T. urticae. The probit -values obtained in the present study are also in accordance with Alves et al. (2002); Irigaray et al. (2003); Draganova and Simova (2010) and Seiedy et al. (2010) against T. urticae. Many isolates of Beauveria species have been found to produce toxic compounds after invasion of the host haemolymph (Roberts, 1981). ...
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.
... It was interesting that all dead insects showed mycosis in their tegument, as present in Figure 1. B. bassiana has a biological cycle of approximately 168 h [28], and T. harzianum, of 120 h nder laboratory condition [29]. The death of the development stages is probably associated with toxic secondary metabolites for the insects synthesized by these fungi after the latter penetrates into the exoskeleton of the former [30]. ...
In 2009, sulfluramid, the main ingredient in toxic baits for leaf-cutting ant control, was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants. This resulted in interest in the use of entomopathogenic fungi such as Beauveria bassiana and Trichoderma harzianum for leaf-cutting ant control. The efficiency of these fungi in controlling these insects and the way that ants react individually or in group to the biological risks posed by these fungi is poorly understood. For this reason, we assessed the effects of B. bassiana and T. harzianum on Atta sexdens rubropilosa larvae, pupae and workers. Moreover, we investigated whether the number of contaminated individuals within a group has an influence in controlling the spread of fungi among workers. We found that the fungus T. harzianum showed high pathogenicity against A. sexdens rubropilosa larvae and pupae, leading to faster mortality and a survival rates. On the other hand, the fungus B. bassiana was responsible for causing faster worker mortality and lower survival rates. In addition, we observed that an increase in individuals contaminated with B. bassiana or T. harzianum in the group decreases its survival rate. The results support the hypothesis that entomopathogenic fungi are efficient in controlling leaf-cutting ants when contaminated workers are allocated to groups of healthy workers.
... During their life cycles, molds develop from spores and grow into mature fungi that produce spores. The life cycle of these fungi comprises two stages: normal growth of mycelia occurs in the stage of externally body on insect pests as well as yeast manners promising stage mainly fluid material of target host body such modification occurred manner of dimorphism way of growing in Beauveria bassiana (Alves et al. 2002), and elliptical blastospore-like propagules are produced by Metarhizium flavoviride (Fargues et al. 2002). The life cycle processes of green muscardine fungus have been studied in fluid media (Uribe and Khachatourians 2008). ...
... Os meios mais ricos em C e N, geralmente produzem mais formas vegetativas: blastosporos, corpos hifais e micélios, sendo muito utilizado sacarose e extrato de levedura para cultivo em meio líquido que resulta em alta produção de conídios(OTTATI-DE-LIMA, 2007). Foi relatado porAlves et al. (2002) que a Beauveria bassiana desenvolvida em meio líquido foi capaz de colonizar insetos hospedeiros através da fase leveduriforme, na qual a fase micelial se diferencia para um estágio de levedura. Desde a década de 60 a produção de fungos está se desenvolvendo no Brasil, e para o desenvolvimento de fungos e a produção de esporos é utilizado cereais como o arroz, que é cozido para que haja a colonização e depois é triturado e lavado para a remoção dos esporos que será o ingrediente ativo do produto de interesse (UHRY, 2007). ...
... Os meios mais ricos em C e N, geralmente produzem mais formas vegetativas: blastosporos, corpos hifais e micélios, sendo muito utilizado sacarose e extrato de levedura para cultivo em meio líquido que resulta em alta produção de conídios(OTTATI-DE-LIMA, 2007). Foi relatado porAlves et al. (2002) que a Beauveria bassiana desenvolvida em meio líquido foi capaz de colonizar insetos hospedeiros através da fase leveduriforme, na qual a fase micelial se diferencia para um estágio de levedura. Desde a década de 60 a produção de fungos está se desenvolvendo no Brasil, e para o desenvolvimento de fungos e a produção de esporos é utilizado cereais como o arroz, que é cozido para que haja a colonização e depois é triturado e lavado para a remoção dos esporos que será o ingrediente ativo do produto de interesse (UHRY, 2007). ...
... Os meios mais ricos em C e N, geralmente produzem mais formas vegetativas: blastosporos, corpos hifais e micélios, sendo muito utilizado sacarose e extrato de levedura para cultivo em meio líquido que resulta em alta produção de conídios(OTTATI-DE-LIMA, 2007). Foi relatado porAlves et al. (2002) que a Beauveria bassiana desenvolvida em meio líquido foi capaz de colonizar insetos hospedeiros através da fase leveduriforme, na qual a fase micelial se diferencia para um estágio de levedura. Desde a década de 60 a produção de fungos está se desenvolvendo no Brasil, e para o desenvolvimento de fungos e a produção de esporos é utilizado cereais como o arroz, que é cozido para que haja a colonização e depois é triturado e lavado para a remoção dos esporos que será o ingrediente ativo do produto de interesse (UHRY, 2007). ...
... A limited number of studies have investigated the activity of blastospores against T. urticae. On one hand Yun et al. (2017) reported a lack of difference between the effect of blastospores and aerial conidia on the mortality of T. urticae; while on the other, Alves et al. (2002) demonstrated higher activity and lower LC 50 of blastospores when compared with aerial conidia. This present study is the first assessment of blastospores efficacy against T. urticae mites under greenhouse conditions. ...
The virulence of aerial conidia of the entomopathogenic fungi Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) has been documented on a very broad range of arthropods; however, the activity of blastospores against the two-spotted spider mite has been seldomly reported. Moreover, studies investigating the activity of blastospores under greenhouse conditions were not found in the literature. In this study, we tested the efficacy of blastospores and aerial conidia of two B. bassiana strains, against all life stages of Tetranychus urticae Koch (Acari: Tetranychidae). The concentration of 109 blastospores/ml of the Lebanese strain was the most efficient in laboratory experiments, and the recorded mortalities were 52, 67.9 and 95.3% in treated eggs, motile juveniles and adults, respectively. In greenhouse experiments, higher T. urticae mortalities were recorded among strawberry plants (Fragaria x ananassa) sprayed with blastospores of B. bassiana. Furthermore, the latter plants also recorded a higher yield (454.92 ± 5 g/plant) compared to infested control plants (144.42 ± 5 g/plant) during the growing season. In addition, this study also investigated for the first time the resistance development of T. urticae to different types of infective propagules of B. bassiana. Under selective pressure for 40 generations, the laboratory yielded aerial conidia (AC-TSM) and blastospores (BS-TSM) resistant strains of the mite recorded 28.8- and 8.4- fold change in LC50 values respectively when compared to the field strain; however, this resistance ratio was minimal when compared to those of chemical acaricides.
... Criv.) causes white muscardine and Metarhizium anisopliae (Metsch.) causes green muscardine disease in target insects [33,34]. Use of Verticillium lecanii (Z.) is suggested as a complementary biological control strategy in an integrated pest management (IPM) program against aphids [35]. ...
Mustard aphid (Lipaphis erysimi) and English grain aphid (Sitobion avenae) are among the most important pests in mustard and wheat fields in Nepal. Biocide Manic (Metarhizium anisopliae a.i. = 1 × 109 spores/ml) at 3 ml/l water, Agri Sakti (Beauveria bassiana a.i. = 1 × 109 spores/ml) at 3.3 ml/l water, Varunastra (Verticillium lecanii spores 2% aqueous suspension, 2 × 108 CFU/ml) at 6 ml/l water, Mahastra (Bacillus thuringiensis var. kurstaki 0.5% wettable powder) at 6 g/l water, Neemraj Super (Azadirachitin 0.3% w/w) at 3.3 ml/l water, Tracer (Spinosad 90% spinosyns) at 0.33 ml/l water, and control treatment (pure water) were used to test their efficacy against L. erysimi and S. avenae, using leaf dip and spray methods under laboratory conditions in Rupandehi, Nepal, in the year 2018. Each treatment was replicated four times, and the experiment was carried out in a randomized complete block design. Mortality of aphids was recorded at 24, 48, 72, and 98 hours after treatment application. The result revealed highest mortality of mustard aphids with Agri Sakti at 24 hours after treatment (HAT); however, Neemraj Super was found to be the most effective at 48, 72, and 96 HAT with the leaf spray method. With the leaf dip method, Neemraj Super killed more mustard aphids than other treatments at all observed time points. Among tested biorational products, Agri Sakti was found to be most effective against English grain aphids in both leaf spray and leaf dip methods. In all the bioassays, the mortality caused by biorational compounds over control was highly significant. The present study suggests for further verification of the biorational products in the field and development of novel management strategies against different species of aphids.
... The genetic pattern of the B. bassiana isolate Bbs01 was obtained by deoxyribonucleic acid (DNA) fingerprinting with a random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Initially, the Bbs01 was grown in a broth media including PDB, SDB, SDBY, MEB, NB and WB in accordance with Alves et al. (2002). Growing materials cooked rice, paddy, millet and dog feed, was prepared by grinding in distilled water at the ratio of 1:1. ...
Molecular biology of indigenous strain of entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillenim (Ascomycota: Hypocreales) (strain Bbs01) based on DNA fingerprinting and enzymatic studies and based on respective RAPD-PCR and acrylamide gel electrophoresis were conducted. The results showed that neither artificial media (PDA, SDA, SDAY, MEA, NA and WA) nor mass production material (cooked rice, paddy, millet and dog feed) effect the fungal genetic stability and protease enzyme activity. Correlation analysis indicated that pathogenicity of Bbs01 to cabbage aphids, Lipaphis erysimi (Hemiptera: Aphididae) and flea beetle, Phyllotreta sinuata (Coleoptera: Chrysomelidae) were increased with protease activity. Accordingly, the most suitable respective artificial and culture material for B. bassiana Bbs01were SDAY and dog food. © 2019 Association of Agricultural Technology in Southeast Asia. All rights reserved.
... Wenzel et al. [24] also estimated the LC 50 of 1.58 × 10 7 conidia/mL for the Brazilian isolate IBCB 66. In another study, Alves et al. [25] obtained the LC 50 of 4.8 × 10 6 conidia/mL for the Brazilian isolate B. bassiana 447 on the third stage larvae of D. saccharalis. However, it is not possible to compare the results obtained because of the methodological differences. ...
A native isolate of the Beauveria sp. fungus obtained from the Diatraea sp. larva was studied and identified as B. bassiana by analyses based on ribosomal internal transcribed spacer (ITS) sequences. The code given to the isolate was Bv062 and its insecticidal activity was evaluated on the second instar larvae of D. sacchara-lis, D. indigenella, D. tabernella and D. busckella, under laboratory conditions, producing mortality rates of 73.3, 83.3, 67.6 and 24.1 %, respectively. Subsequently, the activity of the fungus was evaluated on D. sac-charalis eggs. Egg mortality was of 82.2 % when spraying a conidial suspension adjusted to a concentration of 1 × 10 8 conidia/mL on the eggs. The mean lethal concentration (LC 50) was found to be 9.04 × 10 5 conidia/ mL and the lethal concentration ninety (LC 90) was of 2.07 × 10 7 conidia/mL on the second instar larvae of D. saccharalis. In-plant bioassays under semi-controlled conditions showed that fungus efficacy was above 50 % with the sporulation of dead larvae of 80 %, using concentrations between 1.0 × 10 7 and 5.0 × 10 7 conidia/ mL. Results demonstrated the high potential of B. bassiana Bv062 as a biocontrol agent for the development of a bio-insecticide to be used in the management of different species of the sugarcane stem borer complex. RESUMEN Identificación y caracterización de un aislamiento de Beauveria bassiana (Bals.) Vuill. con alto potencial para el control del barrenador del tallo de la caña de azúcar Diatraea spp. Se estudió un aislamiento na-tivo del hongo Beauveria sp. obtenido de una larva de Diatraea sp., el cual fue identificado molecularmente como B. bassiana mediante el análisis basado en las secuencias de la región espaciadora interna transcrita del ADN ribosomal (ITS). El aislamiento de B. bassiana fue codificado como Bv062 y se evaluó su actividad insecticida sobre larvas de segundo ínstar de D. saccharalis, D. indigenella, D. tabernella y D. busckella en condiciones de laboratorio, donde causó mortalidades del 73.3, 83.3, 67.6 y 24.1 % respectivamente. Posteriormente se evaluó la actividad del hongo sobre huevos de D. saccharalis y se encontró una mortalidad de huevos del 82.2 % al asperjarlos con una suspensión de conidios ajustada a una concentración de 1 × 10 8 conidios/mL. Se determinó una concentración letal media (CL 50) de 9.04 × 10 5 conidios/mL y una concentración letal noventa (CL 90) de 2.07 × 10 7 conidios/mL sobre larvas de segundo ínstar de D. saccharalis. Ensayos de actividad in planta en condiciones semicontroladas evidenciaron una eficacia del hongo superior al 50% con una esporulación de las larvas muertas superior al 80 %, al utilizar concentraciones entre 1.0 × 10 7 y 5.0 × 10 7 conidios/mL. Los resultados demostraron el alto potencial de B. bassiana Bv062 como agente de biocontrol para el futuro desarrollo de un bioinsecticida para el manejo de diferentes especies del complejo del barrenador del tallo de la caña de azúcar en este y otros cultivos hospederos.
... The radial extension rate was somewhat considered an estimation of fungal ability to colonize the substrate on which it grows 26 . The radial extension rates were markedly enhanced after the addition of liquid mediaor standard Sabouraud Dextrose broth 27 . ...
Brewer’s spent grain (BSG) is a promising substrate for the production of biocontrol fertilizer (BF). The effects of temperature, water content and fermentation time on the conidiation and germination rate of the entomopathogenic fungi Beauveria bassiana (BbQLU1) were modeled in a 3 × 3 × 3 factorially designed experiment. The optimum conditions for BF production (60% water content at 25 °C for 12 days) resulted in a conidiation of 0.85 × 108 spores/g and a germination rate of 98.68%. BF at a concentration of 1 × 10−2 g/ml prompted plant growth and exhibited high toxicity against Galleria mellonella with an LT50 of 3.6 days. GC-MS analysis found 2-piperidone; benzoic acid, 3-methyl-, methyl ester; and other compounds to be potentially related to the toxicity and enhanced plant growth. These findings provide substantial evidence to support the production of BF.
... Wenzel et al. [24] also estimated the LC 50 of 1.58 × 10 7 conidia/mL for the Brazilian isolate IBCB 66. In another study, Alves et al. [25] obtained the LC 50 of 4.8 × 10 6 conidia/mL for the Brazilian isolate B. bassiana 447 on the third stage larvae of D. saccharalis. However, it is not possible to compare the results obtained because of the methodological differences. ...
A native isolate of the Beauveria sp. fungus obtained from the Diatraea sp. larva was studied and identified as B. bassiana by analyses based on ribosomal internal transcribed spacer (ITS) sequences. The code given to the isolate was Bv062 and its insecticidal activity was evaluated on the second instar larvae of D. sacchara-lis, D. indigenella, D. tabernella and D. busckella, under laboratory conditions, producing mortality rates of 73.3, 83.3, 67.6 and 24.1 %, respectively. Subsequently, the activity of the fungus was evaluated on D. sac-charalis eggs. Egg mortality was of 82.2 % when spraying a conidial suspension adjusted to a concentration of 1 × 10 8 conidia/mL on the eggs. The mean lethal concentration (LC 50) was found to be 9.04 × 10 5 conidia/ mL and the lethal concentration ninety (LC 90) was of 2.07 × 10 7 conidia/mL on the second instar larvae of D. saccharalis. In-plant bioassays under semi-controlled conditions showed that fungus efficacy was above 50 % with the sporulation of dead larvae of 80 %, using concentrations between 1.0 × 10 7 and 5.0 × 10 7 conidia/ mL. Results demonstrated the high potential of B. bassiana Bv062 as a biocontrol agent for the development of a bio-insecticide to be used in the management of different species of the sugarcane stem borer complex. RESUMEN Identificación y caracterización de un aislamiento de Beauveria bassiana (Bals.) Vuill. con alto potencial para el control del barrenador del tallo de la caña de azúcar Diatraea spp. Se estudió un aislamiento na-tivo del hongo Beauveria sp. obtenido de una larva de Diatraea sp., el cual fue identificado molecularmente como B. bassiana mediante el análisis basado en las secuencias de la región espaciadora interna transcrita del ADN ribosomal (ITS). El aislamiento de B. bassiana fue codificado como Bv062 y se evaluó su actividad insecticida sobre larvas de segundo ínstar de D. saccharalis, D. indigenella, D. tabernella y D. busckella en condiciones de laboratorio, donde causó mortalidades del 73.3, 83.3, 67.6 y 24.1 % respectivamente. Posteriormente se evaluó la actividad del hongo sobre huevos de D. saccharalis y se encontró una mortalidad de huevos del 82.2 % al asperjarlos con una suspensión de conidios ajustada a una concentración de 1 × 10 8 conidios/mL. Se determinó una concentración letal media (CL 50) de 9.04 × 10 5 conidios/mL y una concentración letal noventa (CL 90) de 2.07 × 10 7 conidios/mL sobre larvas de segundo ínstar de D. saccharalis. Ensayos de actividad in planta en condiciones semicontroladas evidenciaron una eficacia del hongo superior al 50% con una esporulación de las larvas muertas superior al 80 %, al utilizar concentraciones entre 1.0 × 10 7 y 5.0 × 10 7 conidios/mL. Los resultados demostraron el alto potencial de B. bassiana Bv062 como agente de biocontrol para el futuro desarrollo de un bioinsecticida para el manejo de diferentes especies del complejo del barrenador del tallo de la caña de azúcar en este y otros cultivos hospederos.
... Wenzel et al. [24] also estimated the LC 50 of 1.58 × 10 7 conidia/mL for the Brazilian isolate IBCB 66. In another study, Alves et al. [25] obtained the LC 50 of 4.8 × 10 6 conidia/mL for the Brazilian isolate B. bassiana 447 on the third stage larvae of D. saccharalis. However, it is not possible to compare the results obtained because of the methodological differences. ...
A native isolate of the Beauveria sp. fungus obtained from the Diatraea sp. larva was studied and identified as B. bassiana by analyses based on ribosomal internal transcribed spacer (ITS) sequences. The code given to the isolate was Bv062 and its insecticidal activity was evaluated on the second instar larvae of D. sacchara-lis, D. indigenella, D. tabernella and D. busckella, under laboratory conditions, producing mortality rates of 73.3, 83.3, 67.6 and 24.1 %, respectively. Subsequently, the activity of the fungus was evaluated on D. sac-charalis eggs. Egg mortality was of 82.2 % when spraying a conidial suspension adjusted to a concentration of 1 × 10 8 conidia/mL on the eggs. The mean lethal concentration (LC 50) was found to be 9.04 × 10 5 conidia/ mL and the lethal concentration ninety (LC 90) was of 2.07 × 10 7 conidia/mL on the second instar larvae of D. saccharalis. In-plant bioassays under semi-controlled conditions showed that fungus efficacy was above 50 % with the sporulation of dead larvae of 80 %, using concentrations between 1.0 × 10 7 and 5.0 × 10 7 conidia/ mL. Results demonstrated the high potential of B. bassiana Bv062 as a biocontrol agent for the development of a bio-insecticide to be used in the management of different species of the sugarcane stem borer complex. RESUMEN Identificación y caracterización de un aislamiento de Beauveria bassiana (Bals.) Vuill. con alto potencial para el control del barrenador del tallo de la caña de azúcar Diatraea spp. Se estudió un aislamiento na-tivo del hongo Beauveria sp. obtenido de una larva de Diatraea sp., el cual fue identificado molecularmente como B. bassiana mediante el análisis basado en las secuencias de la región espaciadora interna transcrita del ADN ribosomal (ITS). El aislamiento de B. bassiana fue codificado como Bv062 y se evaluó su actividad insecticida sobre larvas de segundo ínstar de D. saccharalis, D. indigenella, D. tabernella y D. busckella en condiciones de laboratorio, donde causó mortalidades del 73.3, 83.3, 67.6 y 24.1 % respectivamente. Posteriormente se evaluó la actividad del hongo sobre huevos de D. saccharalis y se encontró una mortalidad de huevos del 82.2 % al asperjarlos con una suspensión de conidios ajustada a una concentración de 1 × 10 8 conidios/mL. Se determinó una concentración letal media (CL 50) de 9.04 × 10 5 conidios/mL y una concentración letal noventa (CL 90) de 2.07 × 10 7 conidios/mL sobre larvas de segundo ínstar de D. saccharalis. Ensayos de actividad in planta en condiciones semicontroladas evidenciaron una eficacia del hongo superior al 50% con una esporulación de las larvas muertas superior al 80 %, al utilizar concentraciones entre 1.0 × 10 7 y 5.0 × 10 7 conidios/mL. Los resultados demostraron el alto potencial de B. bassiana Bv062 como agente de biocontrol para el futuro desarrollo de un bioinsecticida para el manejo de diferentes especies del complejo del barrenador del tallo de la caña de azúcar en este y otros cultivos hospederos.
... However, the studies of pathogenicity on mites show varying results. In studies which employed the commercially available product Naturalis-L (whose active ingredient is B. bassiana) to control T. urticae, a mortality rate on the order of 75 % was reported (Alves et al. 2002;Shi and Feng 2009). A high mortality rate of 97 % was also reported (Chandler et al. 2005). ...
Laboratory studies were developed to evaluate the compatibility of flufenoxuron and azadirachtin with Beauveria
bassiana against Tetranychus
urticae larvae along with the required Probit analysis of the involved chemicals on all of the life stages of this mite. Flufenoxuron displayed parallel regression lines for the mortality of eggs, deutonymphs and adults. Larvae and protonymphs were the most susceptible life stages. Protonymphs were 35 times more sensitive than eggs and adults. Azadirachtin gave equal mortality on proto- and deutonymphs. The response of eggs and adults was equivalent when treated with azadirachtin. The regression lines for proto- and deutonymphs were parallel to those of adults and eggs yet three times more sensitive. The effects of separate combinations of the entomopathogenic fungus Beauveria
bassiana at its LC20 with flufenoxuron and azadirachtin at their corresponding LC40 were evaluated on mite larvae. The application of flufenoxuron with B.
bassiana revealed a clear synergy. While the combination of azadirachtin and B.
bassiana had an additive effect. These combinations with B. bassiana could improve mite control by contributing to a decline in the likelihood of resistance so often described in the literature.
... En general, los hongos entomopatógenos, especialmente los acaropatógenos causan niveles de mortalidad superior al 80 % debido a la especificidad entre el agente de biocontrol y su hospedante y esta efectividad tiende a incrementar a medida que aumenta la concentración de las esporas (Alves et al., 2002). La variación en la virulencia de una especie de hongo podría estar relacionada al tipo de aislamiento, por ejemplo, Draganova y Simova (2010) encontraron que la mortalidad causada por B. bassiana sobre T. urticae varió de acuerdo al aislamiento utilizado y e indicaron que la mayor velocidad de algunos aislados para producir efecto letal podría estar relacionada a la presencia de metabolitos secundarios tóxicos. ...
Red palm mite, Raoiella indica, is considered an economic important pest in coconut plants (Cocos nucifera L.); however, information about ecologically sustainable strategies of control is still scarce. In this study, in vitro effectiveness of ethanolic extract (EE) of pyrethrum (Chrysanthemum cinerariifolium) and compatibility with acaropathogenic fungi (Isaria fumosorosea and Beauveria bassiana) on R. indica control were evaluated. In the laboratory, mites were reared in rearing units using coconut leaf discs cv. Malayan Yellow Dwarf. Mortality of eggs, larva and adult mite by single and combined application of EE (0.25, 0.50, 1.0, 1.5, 2.5, 5, 10 and 15%) and fungus species was demonstrated. Although the EE at 0.25 and 0.5% inhibited the mycelial growth of I. fumosorosea and B. bassiana, conidial production was also promoted in both fungi species. Single or combined use of treatments did not show differences in egg, larvae or adult mite’s mortality; however, the EE seems to provoke a slightly higher effect on the mite. © 2018, Universidad Centroccidental Lisandro Alvarado (UCLA). All rights reserved.
... The fungi Metarhizium anisopliae is an entomopathogenic fungus that has evolved specialized strategies to infect insect hosts. The efficacy of M. anisopliae have been studied for the control of tetranychid mites( Alves et al, 2002). Rodrigo et al(2004) studied the effect of several strains of M. anisopliae against cassava green mite. ...
... Kulat entomopatogen telah mendapat perhatian serata dunia sebagai mikoinsektisid kerana ia mudah untuk dihasilkan secara besar-besaran, banyak perumah alternatif dan mampu mengekalkan tahap jangkitan penyakit yang tinggi untuk masa yang lebih lama. Beauveria bassiana merupakan patogen bawaan tanah yang boleh ditemui di mana-mana di seluruh dunia (Bidochka et al., 2000) dan berpotensi sebagai agen kawalan biologi melalui penyebaran penyakit muscardine di mana serangga yang dijangkiti akan diselaputi dengan lapisan spora putih yang tebal (Alves et al., 2002dan Klinger et al., 2006. Penggunaan kulat sebagai agen kawalan biologi dalam kawalan benah perang telah dikenalpasti oleh Rombach (1986). ...
Abstrak
Benah perang, Nilaparvata lugens Stal. adalah serangga penghisap sap tumbuhan yang mana merupakan serangga perosak utama tanaman padi di Malaysia. Tidak dinafikan benah perang mampu dikawal menggunakan kawalan kimia. Namun begitu, langkah kawalan yang berkesan dan mesra alam sangat diperlukan terutamanya dalam usaha kerajaan menggalakkan pertanian organik dan juga mengurangkan kadar kebergantungan terhadap penggunaan racun kimia dalam bidang pertanian negara. Kulat bersifat entomopatogen seperti Beauveria bassiana dan Hirsutella citriformis telah menunjukkan potensi besar sebagai satu strategi alternatif untuk kawalan mampan beberapa serangga perosak penghisap. Kajian ini bertujuan untuk membangunkan satu program kawalan biologi melalui penilaian potensi isolat-isolat kulat tempatan B. bassiana dan H. citriformis terhadap instar ke-3 dan dewasa N. lugens. Ujian patogenesiti untuk kedua-dua calon telah dilakukan di Makmal Entomologi. Kulat B. bassiana (isolat Bba 0708) adalah yang paling virulen kepada kedua-dua peringkat nimfa dan dewasa benah perang, menyebabkan 47.2% dan 62.2% kematian. Ujian juga dilakukan terhadap pemangsa utama benah perang, Cyrthorhinus lividipennis bagi menilai kadar sensitiviti pemangsa ini terhadap konidia B. bassiana. Didapati tiada sebarang aktiviti sporulasi B. bassiana berlaku kepada C. lividipennis. Pencilan B. bassiana (Bba 0708) pada asalnya diperolehi daripada N. lugens yang dijangkiti secara semula jadi oleh kulat ini. Bukti ini menunjukkan bahawa kulat ini juga berpotensi untuk pembangunan mikoinsectisid bagi mendokong penyelidikan yang berkaitan dengan pengurusan perosak secara bersepadu.
Abstract
Brown planthopper (BPH, Nilaparvata lugens is a devastating floem feeding insect pest of rice. No doubt this insect pest can be effectively controlled using chemical control. However, control measures are effective and environmentally friendly are desperately needed, especially in the government’s efforts to promote organic farming and also reduce dependency on the usage of chemical pesticides in agriculture in the country. Entomopathogenic fungi, such as Beauveria bassiana and Hirsutella citriformis has shown great potential as an alternative strategy for sustainable control of some sucking pests. This study is to evaluate the potential of locally isolated B. bassiana and H. citriformis against 3rd instars and adult Nilaparvata lugens aiming to develop a biological control program for this important rice pest. The pathogenecity tests for both candidates were done in Entomology Laboratory. B. bassiana (isolate Bba 0708) was the most virulent of both nymphs and adults, causing 47.2% and 62.2% mortality, respectively. B. bassiana Bba 0708 was originally obtained from naturally infected N. lugens. The evidence indicates that the potential for development of a mycoinsecticide for support the integrated pest management warrant further studies.
... It has been tested in the laboratory and field against numerous insect and mite pests. Beauveria bassiana has proved to be a potential biocontrol agent against spider mites (Dresner 1949;Andreeva and Shternshis 1995;Alves et al. 1998Alves et al. , 2002Faria and Wraight 2001;Irigaray et al. 2003;Chandler et al. 2005;Seiedy et al. 2010). However, the success of fungal entomopathogens as biological control agents depends not only on the high efficacy against pests, but also on its impact on beneficial arthropods (i.e. ...
... However, different degrees of success have been obtained in different crops and conditions (Zhang and Sanderson, 1995;Kim et al., 1997;Opit et al., 2003;Naher and Haque, 2007). In addition to the use of predatory mites, growers have recently adopted the use of commercial microbial products such as entomopathogenic fungi to control populations of T. urticae (Alves et al., 2002;Chandler et al., 2005;Shi and Feng, 2009;Alma et al., 2007). The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin is among these (Leger et al., 1986). ...
Tetranychus urticae Koch (Acari: Tetranychidae), a major pest of many agricultural crops, is mainly controlled with chemical acaricides. However, predatory mites and entomopathogens have been proposed as alternative control agents. In this study, the effect of the BotaniGard® GHA strain of Beauveria bassiana on the survival, longevity, fecundity, and egg hatch rate of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) were studied under laboratory conditions. When B. bassiana was applied directly to P. persimilis eggs at a concentration of 1 × 10⁸ conidia/ml, corrected hatchability was less than 5%, and the corrected mortality of nymphs and adults was not significantly different from control 10 days after treatment. Phytoseiulus persimilis nymphs that hatched from treated eggs showed no significant change in their development time, adult female longevity, hatch rate, survival rates over time, or offspring sex ratio. However, significant negative effects on fecundity and life table parameters (net reproductive rate, intrinsic rate of natural increase, mean generation time, finite rate of increase, and doubling time) were found when B. bassiana was applied to the adult stage. Spraying B. bassiana at 1 × 10⁸ conidia/ml on newly emerged adults of P. persimilis caused 44% reduction in the oviposition period, 26% in adult longevity, and 63% in fecundity. Due to these negative effects, B. bassiana should be used with careful adjustment of application timing (first spray B. bassiana and then release P. persimilis) to supplement biological mite control systems using P. persimilis.
... Some research have been carried out using entomopathogenic fungi against mites. Alves et al. (2004) reported the potential of using the entomopathogenic fungus, B. bassiana at its yeast phase, to control T. urticae. Furthermore, Barreto et al. (2004) conducted bioaasay studies on B. bassiana and M. anisopliae against the green mite, Mononychellus tanajoa (Bondar) on 3.5 cm diameter cassava leaf discs. ...
Effect of Iranian Bt cotton on life table of Bemisia tabaci (Hemiptera: Alyrodidae) and Cry 1Ab detection in the whitefly honeydew
Arthropods, 2016, 5(3): 87-96
Solmaz Azimi, Shima Rahmani, Masoud Tohidfar, Ahmad Ashouri
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A contribution key for identification of butterflies (Lepidoptera) of Tehsil Tangi, Khyber Pakhtunkhwa, Pakistan
Arthropods, 2016, 5(3): 97-108
Farzana Khan Perveen, Haroon
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Pathogenicity of three entomopathogenic fungi, Metarhizium anisopliae, Beauveria bassiana, and Paecilomyces lilacinus, to Tetranychus kanzawai infesting papaya seedlings
Arthropods, 2016, 5(3): 109-113
Yayan Sanjaya, Virginia R. Ocampo, Barbara L. Caoili
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Toxicity of Metarhizium anisopliae (Deuteromycota: Hyphomycetes) and boric acid against nosocomial cockroaches, Blattella germanica
Arthropods, 2016, 5(3): 114-124
Mohammad Saaid Dayer, Kayhan Karvandian
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First record of terrestrial snail Eobania vermiculata (O.F. Müller, 1774) (Gastropoda: Helicidae) from Basrah areas, Iraq
Arthropods, 2016, 5(3): 125-129
Khaled K. S. Al-Khafaji, Abtsam M. Abud-Sahab, Najim M. Aziz
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... Some research have been carried out using entomopathogenic fungi against mites. Alves et al. (2004) reported the potential of using the entomopathogenic fungus, B. bassiana at its yeast phase, to control T. urticae. Furthermore, Barreto et al. (2004) conducted bioaasay studies on B. bassiana and M. anisopliae against the green mite, Mononychellus tanajoa (Bondar) on 3.5 cm diameter cassava leaf discs. ...
Effect of Iranian Bt cotton on life table of Bemisia tabaci (Hemiptera: Alyrodidae) and Cry 1Ab detection in the whitefly honeydew
Arthropods, 2016, 5(3): 87-96
Solmaz Azimi, Shima Rahmani, Masoud Tohidfar, Ahmad Ashouri
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A contribution key for identification of butterflies (Lepidoptera) of Tehsil Tangi, Khyber Pakhtunkhwa, Pakistan
Arthropods, 2016, 5(3): 97-108
Farzana Khan Perveen, Haroon
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Pathogenicity of three entomopathogenic fungi, Metarhizium anisopliae, Beauveria bassiana, and Paecilomyces lilacinus, to Tetranychus kanzawai infesting papaya seedlings
Arthropods, 2016, 5(3): 109-113
Yayan Sanjaya, Virginia R. Ocampo, Barbara L. Caoili
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Toxicity of Metarhizium anisopliae (Deuteromycota: Hyphomycetes) and boric acid against nosocomial cockroaches, Blattella germanica
Arthropods, 2016, 5(3): 114-124
Mohammad Saaid Dayer, Kayhan Karvandian
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First record of terrestrial snail Eobania vermiculata (O.F. Müller, 1774) (Gastropoda: Helicidae) from Basrah areas, Iraq
Arthropods, 2016, 5(3): 125-129
Khaled K. S. Al-Khafaji, Abtsam M. Abud-Sahab, Najim M. Aziz
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... A morphological study of the cells cultured on melanin films was carried out after 24 and 48 h of cell culture using SEM (T 220-A, Jeol, Tokyo, Japan). 32,33 After the 24 and 48 h test periods, the coverslips were carefully removed and 20 specimens (eight for each group and four negative controls) were used for SEM. Each specimen was fixed over osmium tetroxide vapor (OsO 4 ) for 24 h and then dried for 72 h in a glass desiccator with silica gel, gold-coated in a sputter coater (Balzers, Hammer VII, Alexandria) for 120 s and observed. ...
Biocompatibility tests were performed for melanin synthesized in water (W-Mel) and dimethylsulfoxide (D-Mel) aiming to evaluate its potential for bioelectronics application. In vitro biocompatibility of melanin was assessed using crystal violet assays with fibroblast cells (NIH3T3) cultured with W-Mel and D-Mel extracts in various dilutions. The results show that a high concentration of melanin kills the cells. However, after periods of 48 h incubation, cell viability is significantly favored after treatment with D-Mel at low concentrations (1:16, 1:32 and 1:64), as opposed to treatment with W-Mel extracts. Cellular adhesion tests show that fibroblast cells adhere to melanin thin films. These results show that D-Mel may be an interesting material for application in bioelectronic devices targeted for implants.
Tetranychus urticae is an important pest worldwide. The auto-dissemination of spores of entomopathogenic fungi from an infected individual to conspecifics may be important for controlling pests that can build high populations. The current study was carried out to determine the auto-dissemination of the entomopathogenic fungus Cordyceps fumosorosea strain PFs-1 (Priority®) between T. urticae females. The study consisted of four experiments. First, the efficacy of entomopathogenic fungus bioassays was assessed in Petri dishes (experiment 1) and on potted bean plants (experiment 2). In the auto-dissemination trials (experiments 3 and 4, in Petri dishes and on potted plants, respectively), contaminated adult females (1–5) were released among uncontaminated females (10 individuals). All experiments were carried out separately, and observations were made on days 3, 5, and 7. In exp. 1, the control was different from Priority on all observation days. In exp. 2, the average number of surviving individuals in the control was significantly higher than in the Priority treatment. In the auto-dissemination experiments, as the number of contaminated individuals increased, the mortality rate of uncontaminated individuals also increased, in exp. 3 (Petri dishes) on all observation days, and in exp. 4 (potted plants) only on days 5 and 7. The median lethal time (LT50) decreased as the number of individuals contaminated with Priority increased in both Petri dish and pot trials. Consequently, the effectiveness of biological control may increase with the occurrence of indirect contamination from infected to uncontaminated individuals.
The lethal effects of Beauveria bassiana BIM-001 (1x106 spore mL-1, 1x107 spore mL-1, 1x108 spore mL-1), Fusarium subglutinans 12A (obtained from cotton aphid in Adana-Karataş) and the commercial preparation of 1.5% B. bassiana strain Bb-1 (250 mL da; 1x108 spore mL-1) (Nostalgist SL) on Leptinotarsa decemlineata were investigated. The isolates were applied to the eggs, larvae (1st, 2nd, 3rd, and 4th larval stages) and adults of L. decemlineata by spraying in laboratory conditions (25 ± 1°C, 60 ± 10% relative humidity and 16:8 [L: D] photoperiod). The observations to determine the lethal effect of isolates were performed up to 9 days for the eggs and larvae, and 21 days for the adults of L. decemlineata following the first spore suspension application. In the experiments conducted on the larval stages, it was determined that the mortality rates due to all entomopathogenic fungus isolates and at different concentrations were significantly different from the mortality rate of the control. The effect of all spore concentrations of B. bassiana BIM-001 was found significantly higher than other treatments and the mortality rates were 100% for all larval stages (P ˂0.05). In addition, the mortality rates were between 4 and 16% for adults across all treatment groups except for the control. Moreover, it has been determined that each three spore concentrations of B. bassiana BIM-001 also suppressed the egg hatching of L.decemlineata by 55 to 60%
it is about the beneficial microbes of sugarcane.
Metarhizium rileyi is an entomopathogenic fungus with a narrow host range which distinguishes it from other Metarhizium species with broad host ranges. This species is also unique because the initial yeast-like growth on solid media is only observed in liquid culture in other Metharizium species. A lack of knowledge about the metabolism and genetic signatures of M. rileyi during this yeast-like phase on solid and in liquid media is a bottleneck for its large-scale production as a commercial biocontrol agent. In this study we found that M. rileyi yeast-like cells produced on solid medium infected and killed the important insect pest Spodoptera frugiperda with comparable efficiency as yeast-like cells grown in liquid medium. Secondly, we used comparative transcriptomic analysis to investigate the active genes and genomic signatures of the M. rileyi yeast-like morphotypes produced on solid and in liquid media. Yeast-like cells grown in liquid medium had upregulated genes relating specifically to signal transduction and particular membrane transporters. Thirdly, we compared the transcriptomic profiles of yeast-like phases of M. rileyi with those of M. anisopliae. The yeast-like phase of M. rileyi grown on solid medium upregulated unique genes not found in other Metarhizium species including specific membrane proteins and several virulence factors. Orthologous genes associated with heat shock protein, iron permease, membrane proteins and key virulence traits (e.g. collagen-like protein Mcl1) were upregulated in both species. Comparative transcriptome analyses of gene expression showed more differences than similarities between M. anisopliae and M. rileyi yeast-like cells.
Tetranychus macfarlanei is a potential threat to various economically important crops. Chemical control is widely used to control this spider mite, but the exclusive reliance on chemical acaricides is now being questioned, and entomopathogens are emerging as a promising alternative. The efficacy of the entomopathogens largely depends on abiotic factors like temperature, humidity, rainfall etc. The experiments were conducted to determine the effect of relative humidity on the efficacy of the entomopathogen Beauveria bassiana (strain GHA), marketed as BotaniGard ES, against the adult female and egg stages of T. macfarlanei under laboratory conditions. Adult females and eggs of T. macfarlanei were treated with three concentrations of BotaniGard (1×106, 1×107, and 1×108 conidia/ml), and virulence was assessed on mites held at three relative humidity levels (55, 75, and 95 ± 2% RH) at 25 ± 1 °C. The results showed that the mortalities of adult females and eggs of T. macfarlanei were dose-dependent, and there is certainly a synergistic effect of relative humidity on the efficacy. When the eggs were treated under the above laboratory conditions, highest egg mortalities of 86.4 and 91% were recorded at a concentration of 1×108 conidia/mL at 75 and 95 ± 2% RH, respectively, after six days of treatment. The LT50 values on adult females were 28.7 h and 33.4 h at 95 and 75 ± 2% RH in a concentration of 1×108 conidia/ml, respectively, which was significantly lower than values for other concentrations and RH levels. This study identified 1×108 conidia/ml of B. bassiana at 75 to 95 ± 2% RH as the best possible combination than other lower RH to manage the spider mite.
Background
The mite Tetranychus merganser is considered to be an emerging pest of various crops in tropical countries. It is one of the most detrimental pests in the papaya orchards of some regions of México. The current field control of Tetranychus spp. involves the extensive use of chemicals that have some degree of toxicity to humans or the environment and may cause selective resistance. The use of biological alternatives such as parasitoids and mite predators have limited effectiveness. In order to find effective but non-toxic alternatives for mite pest management, bio-products that are able to be mass produced and applied to large production areas have been sought, including the entomopathogen fungi. B. bassiana and M. anisopliae s.l. are the fungi most extensively used for the biological control of insect pests. Although they do not cause natural epizootic diseases in mites, there are reports that show that they infect T. urticae , and should be evaluated for use in the biological control of papaya’s mite pests.
Methods
A T. merganser colony was established and the susceptibility of adult females to 30 entomopathogenic fungi strains was evaluated under laboratory conditions with an in vitro mass screening bioassay. Ten strains of Metarhizium anisopliae sensu lato (s.l.), eleven of Beauveria bassiana , nine of Lecanicillium sp. and one of Hirsutella thompsonii var. sinematosa were tested. The infectivity of adult females was evaluated calculating the percentage of mortality. To calculate the LC 50 and LT 50 of the most virulent strains, a bioassay was performed using serial concentrations (1×10 ⁴ –1×10 ⁸ conidia/mL) for each strain. Strains showing ability to infect eggs laid were evaluated with a novel egg-infectivity bioassay. The internal transcribed spacer (ITS) region of the more lethal strains were sequenced.
Results
T. merganser and T. urticae were found in orchards of Carica papaya (Maradol variety and Tainung hybrid) in Campeche, México. All tested strains of M. anisopliae s.l. and B. bassiana were infectious to the adult female of T. merganser at a concentration of 1×10 ⁸ conidia/mL. Six strains of M. anisopliae (Ma002, Ma003, Ma004, Ma005, Ma014 and Ma034) caused 100% mortality, and one of B. bassiana (Bb016) caused 95% mortality. The most virulent was Ma034, with an LC 50 of 1.73×10 ⁶ conidia/mL followed by Ma005 and Ma003. Ma005 and Ma034 were the fastest strains to reach LT 50, achieving this in less than 3.7 days. Additionally, Ma034 and Ma014 strains were infectious to more than 70% of the eggs.
Conclusions
T. merganser and T. urticae are present in the papaya orchards of Campeche, México. The high susceptibility of T. merganser adult females and eggs toward several M. anisopliae s.l. or B. bassiana strains suggests that these fungi are a viable alternative to control this emergent pest. The most virulent strain, Ma034, was also infective to eggs, and is the most promising to be tested in the field.
In the Integrated Pest Management of Tetranychus urticae, it is important to use microbiological control agents and acaricides with differing modes of action in order to reduce the risk of resistance, so often reported for this mite. This study evaluates the effect of etoxazole, spirodiclofen, spiromesifen and their compatibility with Beauveria bassiana on the eggs and larvae of T. urticae. For etoxazole and spirodiclofen, the regression lines from the Probit Analysis were parallel in both cases for the two developmental stages. Both acaricides were more effective on eggs than larvae (2.5 and 4.6 times, respectively). The adjusted regression lines of efficacy produced from the bioassays with spiromesifen on eggs and larvae were neither equal nor parallel. However, the confidence intervals for eggs and larvae did overlap at LC99, indicating equal sensitivity in both eggs and larvae at this concentration. The mixture of etoxazole with B. bassiana showed clear antagonistic interaction even though this effect was the result of interference with neither conidial germination nor with the fungus mycelial growth. On the other hand, the combinations of B. bassiana with spirodiclofen and with spiromesifen exhibited additive interaction. The results of this research show that the effectiveness of mixtures of B. bassiana with both spirodiclofen and spiromesifen requires product concentrations to be maintained with no possibility of reduction. Furthermore, the antagonistic effect of the mixture of B. bassiana and etoxazole precludes the combined use of these acaricides in the management of the eggs and larvae of this mite.
A newly discovered entomopathogenic fungus Cordyceps javanica (Friedrichs & Bally) Samson & Hywel-Jones (Hypocreales: Cordycipitaceae) strain Wf GA17 was compared with the commercial Cordyceps fumosorosea Wize (Hypocreales: Cordycipitaceae) Apopka 97 strain for liquid-culture production, formulation, insecticidal efficacy, and storage stability under laboratory conditions. We compared culture media with carbon:nitrogen (C:N) ratios of 10:1, 30:1, and 50:1 for these two isolates. A third strain, C. fumosorosea strain ARSEF 3581, had previously been optimized for liquid-culture production of blastospores at 10:1 C:N served as an added control. These seven cultures were processed by spray drying with skim milk powder, stored at 25oC to evaluate storage stability, and assayed for insecticidal activity against Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) neonates. Final blastospore concentrations were not significantly different among cultures, ranging from 4.47 to 9.88 × 108 spores/ml. Fungal biomass decreased and final glucose concentrations increased with increasing C:N ratios, indicating better fungal growth with higher nitrogen concentrations. Product yields from the spray dryer (grams per liter culture) increased with increased C:N ratios while spore concentrations decreased, ranging from 2.27 to 7.17 × 109 spores/g. There were no significant differences for insecticidal efficacy among the seven treatments. Spores produced in 10:1 C:N ratio media retained viability longer than spores produced in other media. Cost of ingredients decreased with increasing C:N ratios, such that the 30:1 media may yield the most economical product. The raw material cost needed for application was 1.4× greater for Wf GA17 compared with Apopka 97, a difference that could be erased by optimization of culture conditions.
How to cite: Basak, R., Akter, M., Tumpa, T.A., Sharmin, D. & Ullah, M.S. (2021) Laboratory bioassay of six pesticides, an entomopathogenic fungus and botanical pesticide on two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). ABSTRACT The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a serious pest that infests different agricultural crops in Bangladesh. The application of different types of pesticides (botanical and chemical) with various modes of action and bio-pesticides was used for the first time to develop sustainable pest control strategies against spider mites. In this study, the effects of six chemical insecticides viz. abamectin, bifenthrin, bifenazate, etoxazole, hexythiazox, and spinosad, and entomopathogenic fungus Beauveria bassiana and botanical neem oil were evaluated against adult and egg stages of T. urticae under laboratory conditions. Treated mites were kept in controlled conditions at 25 ± 1 ℃, 60-70% RH and a photoperiod of 16:8 h (L: D). The LC50 values of all chemicals [for adults, abamectin (0.51 ml/L), bifenthrin (3.26 ml/L), bifenazate (3.82 ml/L), hexythiazox (3.27 ml/L) and spinosad (3.83 ml/L); for eggs, abamectin (0.56 ml/L), bifenthrin (3.48 ml/L), bifenazate (26.81 ml/L), hexythiazox (4.18 ml/L) and spinosad (18.28 ml/L)] suggest that they were effective against eggs and adult females of the T. urticae. Etoxazole (LC50 = 3.99 ml/L) is recommended against egg stage. The neem oil was found to be moderately effective (for adult, LC50 = 1.26%; for egg, LC50 = 1.77%) against eggs and adult females of T. urticae. The B. bassiana was also found to be effective against eggs and adult females of T. urticae. Finally, it could be concluded that all chemicals used in this study are effective for the management of two spotted spider mite but the entomopathogenic fungus B. bassiana and botanical neem oil were promising alternatives for successful management of T. urticae in IPM programs.
Chemical pesticides tend to accumulate in soil, resulting in human and environmental health risks. Hence, alternative methodologies involving chemical pesticides are beneficial for the control of agricultural pests. Metarhizium anisopliae is an entomopathogenic fungus that acts on different developmental stages of pest insects such as Diatraea saccharalis, a holometabolic lepidopteran with high potential for infestation in sugarcane crops. The present study evaluated the biocontrol effect of M. anisopliae isolates MT and E9 on D. saccharalis eggs at different ages by investigating the external and internal
morphological alterations in treated eggs. Conidial suspensions of M. anisopliae isolated from MT and E9 at concentrations of 107 conidia/mL were applied to eggs of D. saccharalis aged 0, 24, 48, 72, 96 and 120 h. The eggs were observed every 24 h during development (0 h to 144 h). Samples were collected for observational, histological, and ultrastructural analyses. We found that the MT isolate caused 100% inviability of eggs aged 0 - 72 h, 144 h after the bioassays, while the effect of the E9 isolate varied between 49.40% and 93.75%. Melanization was observed on the periphery of the eggs 24 h after the
bioassays. Fungal hyphae developed 48 h after bioassays, crossed the egg chorion, and dispersed through the yolk region, inhibiting embryonic development. After 72 h, hyphae and conidiophores were observed on the eggs, which persisted for 144 h. In sum, M. anisopliae MT isolate can be used as a biological controller for D. saccharalis eggs.
Panonychus citri (citrus red mite) is a devastating pest of citrus orchards. The conventional chemical acaricides have been strongly forbidden for the management of agricultural insect pests in China. Therefore, we evaluated the susceptibility of adult and nymphs P. citri in laboratory against eight isolates of four fungal species, Akanthomyces lecanii, Metarhizium anisopliae, Beauveria bassiana and Aschersonia aleyrodis. Each citrus seedling having 40 adults (2-d-old) and nymphs (on separate plants) were sprayed with isolates at the concentration of 10 4~1 0 8 conidia mLˉ1 whereas controlled seedlings were sprayed with 0.02% Tween-80. After 9 days of fungal exposure, the four fungal isolates caused more than 50% mortality of mites, such as; 85.6%, 87.9%, 64.6% and 79.7% by A. lecanii (V3450), B. bassiana (BFZ0409), M. anisopliae (MFZ0706) and A. aleyrodis (AsG0910), respectively. The nymphal mites were less susceptible to applied fungi compared to adults. The LC 50 s of the tested isolates were determined by the fitted time-concentration-mortality relationships, which declined over days after spray. LT 50 s were decreased with a high concentration of isolates. After the 9-d inoculation, two isolates of B. bassiana (BFZ0409 and D1344) and one isolate of A. lecanii (V3450) were highly effective at the minimal dose of LC 50 of 10 4 conidia mLˉ1 and are promising candidates to control mites, as compared to other tested fungal isolates.
The entomopathogenic fungus, Beauveria bassiana, is capable of infecting pest mites, while the effect on different mite stages has rarely been reported. The present study evaluates the effect of several B. bassiana isolates (GZGY-1-3, LNSZ-26, SDDZ-9, XJWLMQ-32, SCWJ-2 and JXJGS-1) on Tetranychus urticae by a series of assays and observations. A potted bean plant assay indicated the fungal sprays resulted in greater reduction of adult T. urticae populations, but poor suppression in eggs and immature stages. During the one-month experiment, the different fungal isolates reduced the numbers of T. urticae eggs, immatures and adults by 38.7–55.2, 3.7–18.7 and 61.0–72.1%, respectively. Laboratory bioassays showed their corrected mortalities were 2.7–3.8, 17.5–25.8 and 63.2–71.2%, respectively, at seven days days post-fungal treatment. Fecundity of female mites was significantly reduced after fungal spray due to the lethal effect on females, while egg hatchability was not affected. Light microscopy observations indicated fungal outgrowths were evident in mite cadavers, but were not visible on eggs. Scanning electronic microscopy observations demonstrated fungal mycelia grew prolifically from the adult mite 60 h following fungal spray, although no symptoms of fungal infection were exhibited in most immature cadavers. Despite the fact that fungal conidia were able to adhere to and germinate on eggshells, and the germ tubes elongated on the shell surface, they were never observed to penetrate the eggs. Our results demonstrating that the failure to control T. urticae on bean plants using B. bassiana, which we attributed to its poor infectivity to mite eggs and immature stages, may provide useful information in future attempts to develop effective mite control strategies.
Laboratory studies were conducted to evaluate the pathogenicity of three isolates of the fungus Beauveria bassiana (Bals.) Vuil. (B3, B2 and B4). The isolates were used as a suspension at different concentrations (105, 106 and 107 spore/ml), and applied on adults of Tetranychus urticae Koch in the laboratory. Also, the effect of the two isolates B2 and B4 was studied on eggs and fecundity and longevity of adults of T. urticae, at 106, 107 and 108 spore/ml concentration. Results showed high efficacy of the three isolates at all concentrations in killing spider mite adults. The isolate B2 showed the highest virulence compared with other isolates, and caused mortality that reached 70, 80 and 84% at the concentrations of 105, 106 and 107 spores/ml, respectively, thirteen days after treatment. The half lethal time (LT50) attained was 7.65, 7.58 and 8.05 days, respectively. The isolates B4 and B3 caused mortality reached 70 and 78%, respectively, when the concentration of 107 spore/ml was used, and after the same period. Results also showed that the direct effect of the fungus on egg hatching was not important although it differed significantly compared with the control. Egg hatching rates were 87 and 90% when the isolates B2 and B4 were used at concentration 108 spore/ml, respectively, compared with 98% for the control treatment on the 3rd day after treatment. The proportion of mites that were able to complete development to adults, 9 days after egg hatching were 88.66 and 89%, respectively, compared with 100% for the control. The effect of the fungus on mite females fecundity was obvious. When the total fecundity attained was 76.8 egg/female in the control, it was 24.2 and 41.3 egg/female, following treatment with 108 spores/ml of the isolates B2 and B4, respectively.
Irregular and long time work schedules not only makes people feel fatigue, but also brings great risks of diseases, due to gastrointestinal disorder and immune dysfunction. Therefore, it has positive significance to help challenged people stay energetic and healthy with food supplement. Konjac oligosaccharide has shown various physiological benefits and been recommended in the fortification of functional foods. However, there have been few reports on its application aimed to simultaneously relieve physical fatigue and keep body healthy. In this paper, the potential prebiotic, immunoregulatory, and antifatigue activities of konjac oligosaccharide were evaluated in vitro and in vivo. The results showed that konjac oligosaccharide could promote probiotics growth and short chain fatty acids production in mice cecum. At the concentration of 50 to 200 μg/mL, konjac oligosaccharide could activate murine macrophage RAW 264.7 to secret NO and cytokines of IL‐10 and IL‐6. Moreover, this oligosaccharide could alleviate physical fatigue by prolonging exhaustive time, improving the level of superoxide dismutases and glutathione peroxidase, increasing the content of blood glucose, and decreasing the content of blood urea nitrogen. The results suggested that konjac oligosaccharide had prebiotic, immunoregulatory, and antifatigue effects, providing its application potential in functional food aimed at people with irregular and long time work.
Jatropha curcas L. commonly known as purging nut, is often used to produce biodiesel using oil extracted from its seeds, in Mexico, in Totonacapan these (toasted), have been used as human food, making clear its domestication and anthropocentric importance. However, currently this species faces the incidence of various pests, highlighting the leaf-footed bug, Leptoglossus zonatus (Dallas). The incidence of this insect reduces seed yield up to 21%. The use of entomopathogenic fungi can be a viable alternative as biological control. This study aimed to evaluate the pathogenicity and virulence of three Beavueria bassiana (Bals.) strains on adults of this species under laboratory conditions. The BB01 strain isolated from Melanoplus spp., recorded a mortality rate of 85.7% in the first assay and 100% in the second bioassay, strain that was extracted from L. zonatus. The 50 lethal dose (LD50) was 5.2 x 107 conidia ml-1 and lethal time 50 (LT50) was 5.9 days. For mean comparison, the Tukey tests (α= 0.05) and LSD (α= 0.06) were used in the first and second assay respectively. Probit analysis was used for variables LD50 and LT50 using S.A.S version 9.0, concluding that this strain showed greater potential to be used in field conditions as a control agent for the pest.
Pathogenicity of a native strain of Beauveria bassiana Vuill. (Ascomycota: Hypocreales) was evaluated on third-and fifth-instar larvae of tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae). Larvae were immersed in 1×10⁸ conidia ml⁻¹. After 72 hours, the percentage of each treated larval instar that died was 71 and 55%, respectively, while mortality of the nontreated check was 8 and 11%. The fungus was found across the cuticle and grew in the hemocoel 48 to 60 hours after inoculation of third-instar larvae and 60 to 72 hours for fifth instars. Fungal infection events also were studied in tobacco budworm larvae. The microscope and staining procedure showed mycelia grew as filamentous hyphae on the surface and penetrated the cuticle and spiracles; this phenomenon killed larvae. Inside the larvae, fungus grew as filamentous hyphae, but blastospores were not noticed. Results showed many young larval stages died and specific infection events in tobacco budworm compared to other data reported. Results suggested this native strain has potential as a bioinsecticide for tobacco budworm.
House flies are pests of medical and veterinary importance. They are known to be susceptible to fungal conidia presented in sugar baits. The purpose of this study was to evaluate the potential for commercial formulations of entomopathogenic fungi to be used as bait for fly control. Differences in sporulation by product were found. Current formulations may influence fly feeding on baits, but because formulations may protect conidia. Additional research into more attractive formulations is warranted.
The entomopathogen Nomuraea rileyi is a dimorphic hyphomycete having invasive hyphal stages and a yeastlike vegetative stage. Each phenotype has unique characteristics that contribute to pathogenicity of the fungus towards insects. Growth both in vivo and in vitro is highly synchronous. In vitro, conidial germ tubes produce hyphal bodies (yeastlike cells) in complex mycological medium and, if transferred to a less complex medium (Vogel's), the hyphal bodies synchronously convert to mycelia. This transition can be reversed by transferring the mycelia back to the original medium. The hyphal body phase can be by-passed by placing germ tubes directly into Vogel's. The ability to regulate fungal development provides a means of comparing characteristics (e.g., cell surface epitopes, enzyme production) which differ according to phenotype, and to identify genes associated with phase transitions.
Serial in vitro passage of Nomuraea rileyi (Farlow) Samson (UFL 78-6 pathotype) altered both its growth and development on in vitro and in vivo substrates. After only six conidial transfers on Sabouraud maltose and yeast extract agar (SMAY) plates, a reduction in the ability of these cultures to produce the yeastlike, hyphal body stage was observed. Conidia derived from transfers 6-10, although virulent to neonatal Anticarsia gemmatalis Hubner larvae, failed to produce progeny conidia on larvae killed by N. rileyi. Continued serial conidial transfer (> 10) of this pathotype on SMAY resulted in conidia with reduced virulence against neonatal larvae. By the 16th conidial transfer, progeny conidia were avirulent to larvae. The attenuation of N. rileyi was associated with the sporulation process. After multiple vegetative transfers (>80) of the hyphal body stage on SMAY plates, no decrease in virulence to A. gemmatalis was observed.
Spores of fungal pathogens of weeds and insects are unique in their ability to actively infect and kill their pest host.
While these capabilities are advantageous in terms of their use as a contact biological control agent, or biopesticide, they
also require special consideration during spore production. Directed approaches to medium optimization must consider not
only spore yield but also spore qualities such as desiccation tolerance, stability as a dry preparation, and biocontrol
efficacy. Nutritional conditions during culture growth and sporulation should direct the accumulation of appropriate endogenous
reserves so that newly formed spores possess these advantageous qualities. Studies with the bioherbicidal fungus Colletotrichum truncatum and with the bioinsecticidal fungus Paecilomyces fumosoroseus have demonstrated the impact of nutrition on spore ‘fitness’ for use as a biological control agent. The optimization strategy
used in these nutritional studies as well as a comparison of the results are presented.
Ungerminated aerial conidia and four different stages of the growth of Paecilomyces fumosoroseus in submerged culture consisting of swollen conidia, germinated conidia with either one or two germ tubes and hyphal bodies, were assayed for infectivity to 0-to 16-hr-old first-instar larvae of Spodoptera frugiperda at 25 ± 1°C. Germinated conidia and hyphal bodies were more aggressive than ungerminated conidia. Mortality rates in the first larval instar were 29% for larvae contaminated with inactive conidia, 43–49% for larvae treated with germinated conidia, and 61% for larvae treated with hyphal bodies at a dosage of 3 × 104 propagules cm−2. The infective process varied with the type of propagules, with LT50s ranging from 4.0 to 3.1 days. Moreover, the pathogenic activity of the vegetative forms appeared higher than those of the initial ungerminated Inoculum under unfavorable conditions such as reduced fungal dosage (3 × 103 propagules cm), premolt larvae (35–40 hr old), and higher temperature (28 ± 1°C).
The survival of naked and clay-coated Beauveria blastospores in soil was investigated with an experimental biodegradation method using a trap technique. At various times of incubation, traps were collected to study changes in biomass, inoculum potential, and infection potential of degraded blastospores, and to investigate the colonization of blastospore biomass by antagonistic soil-borne microorganisms. Infection potential was tested on larvae of Plutella maculipennis and Leptinotarsa decemlineata. Naked blastospores were inactivated after 3 weeks incubation, while clay-coated blastospores were still active after 2 months incubation in soil at 20°C. All investigations demonstrated the protective role of clay coating against biodegradation of fungal propagules by soil bacteria and protozoa. Consequently, clay coating of blastospores is proposed for the formulation of entomopathogenic hyphomycetes propagules. Moreover, antagonists implicated in lysis of blastospores, must be considered as an important part of the environmental response to a massive introduction of a fungus used for insect control.
Determinations were made of the median lethal concentration (LC50) and median lethal time (LT50) of conidia and blastospores of B. bassiana against adult Nephotettix virescens (green leafhoppers). There was no significant difference between the LC50 values for blastospores produced in carbon- and nitrogen-limited cultures, but both types of blastospores were significantly less virulent than conidia. The LT50 values of conidia and of blastospores from nitrogen-limited cultures were significantly lower than the value for blastospores produced in carbon-limited culture. The LT50 values of conidia and blastospores increased during storage at 25 °C and were inversely related to spore viability.
At all but one concentration tested, nitrogen-limited blastospores ‘adhered’ to insects more strongly than did carbon-limited blastospores. Fewer spores germinated on insect wings than on agar medium and of the three spore types studied, maximal germination on insect wings was observed with nitrogen-limited blastospores.
Vapor fixation for 96 h with 1% osmium tetroxide (OsO4) and 3–4 days air drying produced distortion-free specimens of Beauveria spp. for examination with the scanning electron microscope. A combination of 4 h OsO4 vapor fixation and freeze-drying also reduced disruption satisfactorily but specimens were not as well preserved as with the first method. Preparation methods that were ineffective in preventing collapse of hydrophilic structures were Cling Free® sprayed on specimens prior to examination, freeze-drying, critical-point drying (of unfixed material), and vapor fixation with glutaraldehyde.
The different effects of conidia of Beauveria bassiana applied to Solenopsis invicta either directly, via soil (sterile or non-sterile) or via the surface of a petri dish, were investigated. S. invicta that were sprayed with conidia were then held in clean plastic cups, or with sterile or non-sterile nest soil. Mortalities of insects sprayed directly with conidia were similar irrespective of whether they were then held with or without soil. When treatment was administered by incorporation into sterile soil, a concn of 106 conidia/g soil caused 90% mortality while in nonsterile soil the greatest mortality, just more than 50%, was caused by concn greater than 108 conidia/g soil. Removing insects after 3 days from nonsterile soil treated with 3 x 107 conidia/g soil increased mortality to 15%, as compared to 4% if the insects were left with the soil for 15 days. Exposure to petri dish surfaces treated with 104 conidia/mm2 resulted in almost 100% mortality of S. invicta. The LD50 and LD90 were calculated to be 2.1 x 103 and 4.4 x 104 conidia/individual, resp.
Seventy-two isolates of Beauveria bassiana or Metarhizium anisopliae were screened for control of Sitophilus oryzae, S. zeamais and Rhyzopertha dominica. Beauveria bassiana isolates produced the highest mortalities against all three hosts. Ten isolates (all B. bassiana) were selected for further experimentation in the second phase of the selection process. Bioassays were conducted by inoculating 50 adult insects of each species, maintained at 26 plus or minus 0.5 deg C, 70 plus or minus 10% RH, 12 h photophase, for 10 days. The cumulative mortalities after 10 days exposure and lethal time for 50% of the population (LT50) were calculated and compared. S. oryzae and S. zeamais were less susceptible to B. bassiana isolates than R. dominica, which was completely killed by several isolates. Isolate 476 was the most virulent to S. oryzae, and isolate 604 was the most virulent to S. zeamais. Isolate 604 was best overall, but isolates 476 and 643 should also be considered as control agents for stored-grain pests. A combination of isolates may be advantageous if mixed pest infestations occur.
Experiments were conducted to determine the pathogenicity, virulence and mass production yields of Beauveria spp. isolates as potential microbial control candidates for Heterotermes tenuis. Results demonstrated that the average virulence of the B. brongniartii isolates was comparable to that of B. bassiana isolates. Isolates obtained from soil were as effective as microbial control agents as those obtained directly from insect hosts. However, no B. brongniartii or soil isolate was among those best isolates selected, which included two of the three termite isolates tested. LT50s for 15 selected isolates varied between 2.91 and 4.91 days, and termite mortalities caused by these isolates were between 78.7 and 98.7% after 8 days. Significant differences were observed among these selected isolates. Conidial productions on artificial media (PDA and cooked rice) correlated well for the selected isolates. However, spore production on termite cadavers did not correlate with production on these artificial media. The most productive isolate on cadavers (634) was 21% more productive than the second best isolate (447), and was also a good conidial producer on artificial media with 25% lower conidial yield than the best producer (756). The least productive isolate on cadavers or artificial medium (760) produced only 3% of production by isolate 756 on cooked rice and 45% of production on termite cadavers. Because high conidial production on cadavers is a desirable characteristic to facilitate transmission of the disease in the nest, isolate 634 was selected for further development as a microbial agent for H. tenuis control.
Liquid media with differing carbon concentrations and carbon-to-nitrogen ratios were tested for production of desiccation tolerant blastospores of Paecilomyces fumosoroseus. While all media tested supported sporulation in submerged culture, high blastospore concentrations (5·8 × 108) spores ml−) were produced in media containing 80 g glucose l− and 13·2 g Casamino acids l− (MS medium) and a significantly higher percentage (79%) of these blastospores survived air drying. Media containing glucose concentrations greater than 20 g l − and Casamino acid concentrations between 13·2 and 40 g l− supported maximal production of desiccation tolerant blastospores. All 23 isolates of P. fumosoroseus grown in MS media produced high concentrations of desiccation tolerant blastospores. When stored at 4 °C, more than 60% of the lyophilized blastospores produced in MS medium were still viable after 7 months storage while less than 25% of the air-dried blastospores survived after 90 d storage. Standard whitefly bioassays were performed to compare air-dried blastospores of P. fumosoroseus ARSEF 4491 with solid substrate-produced conidia of Beauveria bassiana ARSEF 252. Air-dried blastospores of P. fumosoroseus gave LD50s of 60 and 113 blastospores mm− for the silverleaf whitefly (Bemisia argentifolii) in two separate bioassays with potency ratios (LD50B. bassiana/LD50P. fumosoroseus)of 3·9 and 3·8, respectively. These results have demonstrated that high concentrations of blastospores of P. fumosoroseus can be rapidly produced in liquid culture, remain viable following drying, and infect and kill silverleaf whitefly.
Controle Microbiano de Insetos
- S.B Alves
- S.B Alves
Aubart Biodegradation of entomopathogenic hyphomycetes: influence of clay coating on Beauveria bassiana blastospore survival in soil
- Fargues
- Fargues
S Tigano Cytology of the yeast-like structures of Beauveria bassiana in liquid media and in the hemolymph of Spodoptera frugiperda Rev
- Lima
- E A D L Tigano
- M Lima
- Lima
- E A D L Tigano
- M Lima
Gillespie Influence of cultural conditions on the virulence of conidia and blastospores of Beauveria bassiana to the green leafhopper
- Lane
- Lane
M Pereira Efficacy of Beauveria bassiana (Balsamo) Vuillemin isolates for control of stored-grain pests
- Moino
- Moino
Cytology of the yeast-like structures of Beauveria bassiana in liquid media and in the hemolymph of Spodoptera frugiperda
- Lima
Lima, E.A.D.L.A., Tigano, M.S., 1989. Cytology of the yeast-like structures of Beauveria bassiana in liquid media and in the hemolymph of Spodoptera frugiperda. Rev. Microbiol. 20, 85–94.
Cell wall composition is important in eliciting insect immune system reaction and may deter-mine the fate of pathogen in different hosts
- Macconkey
MacConkey agar. Cell wall composition is important in eliciting insect immune system reaction and may deter-mine the fate of pathogen in different hosts.
Diatraea saccharalis
- King
King, E.G., Hartley, G.G., 1985. Diatraea saccharalis. In: Singh, P., Moore, R.F. (Eds.), Handbook of Insect Rearing, vol.