ABSTRACT
Entomopathogenic Fungal agents play an important role in controlling pest population. Besides isolating and exploiting the virulent fungal agents it is essential to maintain its viability for longer period at affordable cost, thereby they could be employed for further research. Usage of oils and storage at lower temperatures prevent conidial desiccations and could be comparatively a cheaper alternative to freeze drying and cryopreservation to maintain its virulence for extended periods. Oil cultures of Beauveria bassiana (Balsamo) Vuillemin were prepared from the laboratory-maintained isolate by using two vegetable oils viz., Rice Bran oil, Sesamum oil and two mineral oils viz., Liquid Paraffin oil and Heavy grade Mineral Oil. Prepared oil cultures were stored under three different temperature regimes viz., at room temperature (28 ± 3ºC), refrigerated condition (4ºC) and freezing temperature (-20ºC). These 12 cultures stored at different temperatures along with crude culture and untreated control were evaluated for viability and virulence against third instar Spodoptera litura (Fabricius) larvae on the day of preparation (0 DAS) and upto 180 days under laboratory conditions. Among all oil cultures, Sesamum oil cultures and Liquid Paraffin oil cultures stored at -20ºC performed well with highest conidial germination of 87.85% and 83.57% and highest larval mortality of 90.00% and 86.67% on the day of preparation (0 DAS). After 180 DAS of storage, conidial germination in these two formulations was in the range of 62.87% to 61.43% and larval mortality was 60.00%. Comparatively, least performance was observed in mineral oil formulations stored at room temperature(T1) and in unformulated crude cultures.
ABSTRACT
The present study was carried out in laboratory conditions (25 ± 10°C and 70% humidity) for studying the bioefficacy of entomopathogenic fungi and Bacillus thuringiensis against Spodoptera litura using the leaf dip method. The insecticidal attributes of three different commercial bioinsecticides (Bacillus thuringiensis 0.5% W.P., Beauveria bassiana 1.0% W.P., and Metarhizium anisopliae 1.0% W.P.) at different concentrations (0.5, 1.0, and 1.5%) were evaluated against the 3rd and 4th larval instars of S. litura. The analysis of variance results revealed that the highest concentration (1.5% concentration) of B. thuringiensis against the 3rd instar larvae of S. litura caused a maximum 80 ± 0.28% larval mortality, followed by B. bassiana and M. anisopliae, which caused 72 ± 0.21 and 64 ± 0.20% larval mortality after 120 h exposure. The calculated median lethal concentration in probit analysis demonstrated the lowest median lethal concentration of 1.22/10 larvae (95% fiducial limit 4.71–11.45) in the 3rd instar larvae after 72 h. Similarly, in 4th instar larvae of S. litura, the highest concentration (1.5% concentration) of B. thuringiensis caused maximum 76 ± 0.23% larval mortality, followed by B. bassiana and M. anisopliae, causing 70 ± 0.21% and 64 ± 0.20% larval mortality after 120 h. The calculated median lethal concentration in probit analysis demonstrated the lowest LC50 = 1.59/10 larvae (95% FL: 1.08–2.36) in the 4th instar larvae after 72 h. Based on these studies, it was revealed that B. thuringiensis and B. bassiana showed maximum efficacy against S. litura larvae. Although M. anisopliae also exhibits insecticidal properties, all of these bioinsecticides can be used to manage the population of S. litura. These bioinsecticides can be included in integrated pest management programs as they do not pose any toxic hazards to the environment.
ABSTRACT
Two fungal isolates, resembling Beauveria bassiana and Metarhizium rileyi were collected and cultured from the ?elds of okra and groundnut at Ranchi, Jharkhand, India. This is the ?rst record of these fungi from Chotanagpur Plateau region. Their DNA was isolated and ampli?ed using the universal ITS1 and ITS4 primers. The ampli?ed product obtained was of the size of 500 bp for Beauveria bassiana and 550 bp for Metarhizium rileyi. Sequencing was performed using ITS1 primer. Comparing the respective sequences showed 97% resemblance to Beauveria bassiana and Metarhizium rileyi respectively. Multiple sequence alignment of ITS sequence of both the newly isolated strains along with its homologous sequences was conducted and a phylogenetic tree was built following the Neighbor-Joining method.
ABSTRACT
Rice productivity is impaired by sucking, leaf feeding and borer insect pests. Among the leaf feeders, rice leaf folder Cnaphalocrocis medinalis (Guenee) cause significant yield loss. The non-chemical insect pest management is gaining momentum among farmers, and biocontrol management is one of the essential components. The efficacy of entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin isolate against C. medinalis was studied using the laboratory culture maintained in rice leaves. Different concentrations of B. bassiana were applied topically on the second instar C. medinalis larvae. The mortality observations were recorded at 48 hrs intervals from the third day and continued up to 11 days. The highest mortality of 78.33% was observed at concentration 1×108 conidia/ml, and the lowest mortality of 36.67% was observed at concentration 1×103 conidia/ml. The determined median lethal concentration (LC50) of B. bassiana (Balsamo) Vuillemin isolate against C. medinalis is 5.44 x 105 conidia/ml.
ABSTRACT
The field experiment was carried out in the Rabi season of 2022-2023 at Central Research Farm (CRF), Sam Higginbottom University of Agriculture, Technology And Sciences, Prayagraj. The field was replicated with three randomised block design (RBD) of eight treatments including control (water spray) viz., Indoxacarb 14.5% SC, Chlorantraniliprole 18.5% SC, Emamectin benzoate 5% SG, Emamectin benzoate 5% SG+Indoxacarb14.5% SC, Beauveria bassiana 1.5% WP, NSKE 5%, Neem oil 5% and one control plot (water spray). The maximum reduction of larval population was recorded in T3 Emamectin benzoate 5% SG (78.9%) followed by T2 Chlorantraniliprole 18.5% SC (76.2%), T4 Emamectin benzoate 5% SG + Indoxacarb 14.5% SC (68.2%), T1 Indoxacarb 14.5% SC (65.8%), T6 NSKE 5% (59.3%), T5 Beauveria bassiana 1×108CFU\G (54.7%) was found next effective treatments. Among all the treatments T7 Neem oil 5% (49.4%) was found least effective but comparatively superior over untreated plot (0%).
ABSTRACT
It is unclear how VvLaeA functions in regulating the growth and development of Volvariella volvacea (Bull. ex. Fr.) Sing.. Firstly, bioinformatics analysis of VvLaeA was carried out in this study. Subsequently, the Vvgpd promoter and the open reading frame (ORF) fragment of VvlaeA were amplified and fused by polymerase chain reaction (PCR). The fusion fragment was cloned into the pK2 (bar) plasmid. The recombinant construct pK2(bar)-OEVvlaeA was transfected into Beauveria bassiana by Agrobacterium tumefaciens-mediated transformation. Finally, the growth and development of the transformants were examined. The results showed that VvLaeA shared a low homology with similar proteins in other fungi. Compared with the wild type, the colony diameter of the transformant was significantly increased. However, the pigment deposition, conidial yields and germination rates were significantly decreased. The overexpression strains were more sensitive to stresses than that of the wild type. Further studies showed the conidial cell wall properties of the transformants were altered, and the expressions of genes related to the conidial development were significantly down-regulated. Collectively, VvLaeA increased the growth rate of B. bassiana strains and negatively regulated the pigmentation and conidial development, which shed a light for the functional identification of straw mushroom genes.
Subject(s)
Beauveria/metabolism , Spores, Fungal , Growth and DevelopmentABSTRACT
Beauveria bassiana belongs to the class Deuteromycetes which is one of the important disease-causing biocontrol agents in insects. B. bassiana, formerly known as Botrytis bassiana (Balsamo), is a widely distributed soil inhabiting fungus. B. bassiana is also known to be best biocontrol agent against larval stage of the silkworm. B. bassiana is categorized as a white muscardine fungus due to the white color of sporulating colonies. It is a type of biopesticide which is based on entomopathogenic fungi which are often considerable scope as plant protection agents against several pathogens and insects including whiteflies, aphids, thrips, grasshoppers, and certain types of beetles. The present study deals with the use of different media such as coconut media, jaggery media, nutrient media, potato dextrose media, Sabouraud dextrose media, and molasses media
ABSTRACT
Abstract Beauveria bassiana is a promising fungus for the biological control of insect pests. The growing costs of conidia production have raised the need to ascertain the efficiency of some low cost substrates. The aim of this study was to analyze the potential use of different raw substrates without nutritional supplement for B. bassiana conidiogenesis. Growth and sporulation were evaluated using 30 g of substrate and 0.3 μL of a conidia suspension (1 x 106 conidia/mL). After 10 days of incubation (70 ± 10% humidity and temperature (T) = 29 ± 1 °C), rice (2.00 x 106 conidia/g substrate), algaroba (2.36 x 106 conidia/g), malt A (1.22 x 106 conidia/g) and malt B (1.75 x 106 conidia/g) showed the highest levels of conidia production. The resulting conidia showed insecticidal activity higher than 80% on coconut termites. These new raw substrates may represent viable alternatives for the production of entomopathogenic fungi for use in the biological control of various insect pests.
Resumo Beauveria bassiana é um fungo promissor no controle biológico de insetos-praga. As crescentes despesas na produção de conídios levantam a necessidade de averiguar a eficiência de alguns substratos de baixo custo. O objetivo deste trabalho foi analisar o potencial de utilização de diferentes substratos brutos para a conidiogênese de B. bassiana. O crescimento e esporulação foram realizados utilizando 30 g do substrato e 0,3 µL da suspensão de conídios (1 x 106 conídios/mL). Após 10 dias de incubação (umidade 70 ± 10% e temperatura T = 29 ± 1° C), o arroz (2,00 x 106 conídios/g de substrato), algaroba (2,36 x 106 conídios/g), malte A (1,22 x 106 conídios/g) e B (1,75 x 106 conídios/g), apresentaram maior produção de conídios. Os conídios produzidos mostraram atividade inseticida sobre o cupim do coqueiro acima de 80% de mortalidade. Estes novos substratos brutos podem representar uma alternativa viável para produção de fungos entomopatogênicos para uso no controle biológico de vários insetos praga.
Subject(s)
Mitosporic Fungi , Beauveria , Spores, Fungal , Pest Control, Biological , HumidityABSTRACT
The use of acaricides is the main control method for Tetranychus ludeni (Acari: Tetranychidae) in horticultural crops. This mite has been recorded causing damage to sweet potato (Ipomoea batatas L.). The use of pathogenic fungi is an alternative to chemical control. The objective was to evaluate the pathogenicity of the fungi Metarhizium anisopliae (Meetch) Sorok, and Beauveria bassiana (Bals.) Vuill. to phytophagous mite T. ludeni in sweet potato plants. Conidial suspensions of M. anisopliae and B. bassiana, at concentrations of 106 and 107 con.mL-1 were applied to sweet potato leaves. After 24 hours, five females of T. ludeni newly emerged were released on the leaves. The bioassay was arranged in a completely randomized design with factorial arrangement 2 × 2 (two species of fungi and two concentrations) plus the control (distilled water), with 10 repetitions per treatment. The evaluation consisted of observing of three biological parameters of the mite: mortality, oviposition, and repellency, after 24, 48, 72, and 96 hours of contact with the fungi. The isolates of M. anisopliae cause high mortality rates of T. ludeni in laboratory. Beauveria bassiana has the potential to suppress future generations of mite, reducing its oviposition rate. Repellency behavior was not observed.(AU)
O uso de acaricidas é o principal método de controle de Tetranychus ludeni (Acari: Tetranychidae) em cultivos hortícolas. Esse ácaro foi registrado causando danos em batata-doce (Ipomoea batatas (L.). A utilização de fungos patogênicos é uma alternativa ao controle químico. O objetivo foi avaliar a patogenicidade dos fungos Metarhizium anisopliae (Meetch) Sorok. e Beauveria bassiana (Bals.) Vuill. ao ácaro fitófago T. ludeni em batata-doce. Suspensões conidiais de M. anisopliae e B. bassiana, nas concentrações de 106 e 107 con.mL-1, foram aplicadas sobre folhas de batata-doce. Após 24 horas, cinco fêmeas recém-emergidas foram liberadas sobre as folhas. O bioensaio foi inteiramente randomizado, com arranjo fatorial 2 × 2 (duas espécies de fungos e duas concentrações) e controle (água destilada), com 10 replicações por tratamento. A avaliação consistiu na observação de três parâmetros biológicos do ácaro: mortalidade, oviposição e repelência, após 24, 48, 72 e 96 horas de contato com os fungos. Os isolados de M. anisopliae causam altas taxas de mortalidade de T. ludeni em laboratório. Beauveria bassiana tem potencial para suprimir futuras gerações do ácaro, reduzindo a taxa de oviposição. Comportamento de repelência nos ácaros não foi observado.(AU)
Subject(s)
Animals , Male , Female , Tetranychidae/microbiology , Beauveria/pathogenicity , Metarhizium/pathogenicity , Random Allocation , Pest Control, Biological , Ipomoea batatasABSTRACT
ABSTRACT The selectivity of five entomopathogens and a chemical insecticide (positive control) to pupae and adults of the egg parasitoid Telenomus remus (Nixon) was evaluated in the laboratory under controlled environmental conditions according to protocols established by the International Organization for Biological Control. Baculovirus anticarsia (Baculovirus AEE®), Bacillus thuringiensis var. kurstaki (Thuricide®), Bacillus thuringiensis var. aizawai (Agree®), Beauveria bassiana (Boveril®), Metarhizium anisopliae (Metarril®) and Trichoderma harzianum (Trichodermil®) are harmless to T. remus pupae, and adults. Thus, our results suggest that the insect control strategies applied here are compatible since entomopathogens were classified as harmless to T. remus in most examined cases and therefore facilitate a joint application to control different pests. Bacillus thuringiensis var. kurstaki (Dipel®), despite being classified as slightly harmful in some of the evaluations, can still be considered compatible for use together with T. remus, especially when compared with chemical insecticides such as chlorpyrifos that might be considered harmful to the parasitoid survival.
ABSTRACT
This work aimed to evaluate the effects of the products Biogermex®, Agro-mos®, Soil-Set® and Planta Clean® on the development of white muscardine in Bombyx mori. Products have been tested at two stages for effects on biology of caterpillars and on silk production (1), and then they were evaluated to know their potential in the prevention/control of white muscardine (2). Products were sprayed on mulberry leaves (preventive treatment) and also on the integument of silkworms (curative treatment). At the first stage, the products were applied on four consecutive days, in one of the daily feeds. Planta Clean® - curative treatment - and Soil-Set® - preventive treatment - caused mortality in 63.3% and 30% of silk worms, respectively. The fungus Beauveria bassiana was inoculated at the concentration 5 × 107 conidia/mL on the leaves and insects. The products were applied three hours after application on the fungus, in a single application, and also for four days in the other groups. A group of silkworms sprayed only with the fungus served as control. Biogermex® - curative treatment applied once and for four times - was the most effective, reducing mortality by 25 and 26.7%, respectively, as compared with the control group. None of the evaluated products acts preventively against white muscardine.
Este trabalho objetivou avaliar os efeitos de produtos Biogermex®, Agro-mos®, Soil-Set® e Planta Clean® no desenvolvimento da calcinose branca em Bombyx mori. Os produtos foram testados em duas etapas: efeitos sobre a biologia e produção de seda pela lagarta (1) e, em seguida, em função do seu potencial na prevenção/no controle da calcinose branca (2). Os produtos foram pulverizados sobre as folhas de amoreira (tratamento preventivo) e sobre o tegumento das lagartas (tratamento curativo). Na primeira etapa, os produtos foram aplicados durante quatro dias consecutivos, em uma das alimentações do dia. Planta Clean® - tratamento curativo - e Soil-Set® - tratamento preventivo - causaram mortalidade em 63,3 e 30% das lagartas, respectivamente. O fungo Beauveria bassiana foi inoculado na concentração 5 × 107 conídios/mL sobre folhas e insetos. Os produtos foram aplicados três horas após o fungo, em uma aplicação, e também por quatro dias em outro grupo. Um grupo de lagartas pulverizadas apenas com fungo serviu como controle. Biogermex® - tratamento curativo aplicado uma e quatro vezes - foi o mais eficiente, reduzindo a mortalidade em 25 e 26,7% respectivamente, em relação ao grupo controle. Nenhum dos produtos avaliados atuou de forma preventiva contra muscardina branca.
Subject(s)
Animals , Beauveria , Bombyx , Calcinosis , Pesticides , InsectaABSTRACT
Abstract Beauveria bassiana is a promising fungus for the biological control of insect pests. The growing costs of conidia production have raised the need to ascertain the efficiency of some low cost substrates. The aim of this study was to analyze the potential use of different raw substrates without nutritional supplement for B. bassiana conidiogenesis. Growth and sporulation were evaluated using 30 g of substrate and 0.3 L of a conidia suspension (1 x 106 conidia/mL). After 10 days of incubation (70 ± 10% humidity and temperature (T) = 29 ± 1 °C), rice (2.00 x 106 conidia/g substrate), algaroba (2.36 x 106 conidia/g), malt A (1.22 x 106 conidia/g) and malt B (1.75 x 106 conidia/g) showed the highest levels of conidia production. The resulting conidia showed insecticidal activity higher than 80% on coconut termites. These new raw substrates may represent viable alternatives for the production of entomopathogenic fungi for use in the biological control of various insect pests.
Resumo Beauveria bassiana é um fungo promissor no controle biológico de insetos-praga. As crescentes despesas na produção de conídios levantam a necessidade de averiguar a eficiência de alguns substratos de baixo custo. O objetivo deste trabalho foi analisar o potencial de utilização de diferentes substratos brutos para a conidiogênese de B. bassiana. O crescimento e esporulação foram realizados utilizando 30 g do substrato e 0,3 µL da suspensão de conídios (1 x 106 conídios/mL). Após 10 dias de incubação (umidade 70 ± 10% e temperatura T = 29 ± 1° C), o arroz (2,00 x 106 conídios/g de substrato), algaroba (2,36 x 106 conídios/g), malte A (1,22 x 106 conídios/g) e B (1,75 x 106 conídios/g), apresentaram maior produção de conídios. Os conídios produzidos mostraram atividade inseticida sobre o cupim do coqueiro acima de 80% de mortalidade. Estes novos substratos brutos podem representar uma alternativa viável para produção de fungos entomopatogênicos para uso no controle biológico de vários insetos praga.
ABSTRACT
This work aimed to evaluate the effects of the products Biogermex®, Agro-mos®, Soil-Set® and Planta Clean® on the development of white muscardine in Bombyx mori. Products have been tested at two stages for effects on biology of caterpillars and on silk production (1), and then they were evaluated to know their potential in the prevention/control of white muscardine (2). Products were sprayed on mulberry leaves (preventive treatment) and also on the integument of silkworms (curative treatment). At the first stage, the products were applied on four consecutive days, in one of the daily feeds. Planta Clean® - curative treatment - and Soil-Set® - preventive treatment - caused mortality in 63.3% and 30% of silk worms, respectively. The fungus Beauveria bassiana was inoculated at the concentration 5 × 107 conidia/mL on the leaves and insects. The products were applied three hours after application on the fungus, in a single application, and also for four days in the other groups. A group of silkworms sprayed only with the fungus served as control. Biogermex® - curative treatment applied once and for four times - was the most effective, reducing mortality by 25 and 26.7%, respectively, as compared with the control group. None of the evaluated products acts preventively against white muscardine.(AU)
Este trabalho objetivou avaliar os efeitos de produtos Biogermex®, Agro-mos®, Soil-Set® e Planta Clean® no desenvolvimento da calcinose branca em Bombyx mori. Os produtos foram testados em duas etapas: efeitos sobre a biologia e produção de seda pela lagarta (1) e, em seguida, em função do seu potencial na prevenção/no controle da calcinose branca (2). Os produtos foram pulverizados sobre as folhas de amoreira (tratamento preventivo) e sobre o tegumento das lagartas (tratamento curativo). Na primeira etapa, os produtos foram aplicados durante quatro dias consecutivos, em uma das alimentações do dia. Planta Clean® - tratamento curativo - e Soil-Set® - tratamento preventivo - causaram mortalidade em 63,3 e 30% das lagartas, respectivamente. O fungo Beauveria bassiana foi inoculado na concentração 5 × 107 conídios/mL sobre folhas e insetos. Os produtos foram aplicados três horas após o fungo, em uma aplicação, e também por quatro dias em outro grupo. Um grupo de lagartas pulverizadas apenas com fungo serviu como controle. Biogermex® - tratamento curativo aplicado uma e quatro vezes - foi o mais eficiente, reduzindo a mortalidade em 25 e 26,7% respectivamente, em relação ao grupo controle. Nenhum dos produtos avaliados atuou de forma preventiva contra muscardina branca.(AU)
Subject(s)
Animals , Pesticides , Bombyx , Calcinosis , Beauveria , InsectaABSTRACT
Aims: Subterranean termites, Globitermes sulphureus is one of the significant pests for agricultural crops such as coconut and oil palm, and occasionally attacks building structure in Malaysia. Efforts to control subterranean termite infestations depended heavily on liquid termiticide applications. Natural pathogen of termites such as entomopathogenic fungi (EPF) is a promising alternative to chemical control. The objective of this study was to determine the most virulent EPF such as Metarhizium anisopliae, Beauveria bassiana and Paecilomyces sp. against the subterranean termites, G. sulphureus for the development of bio-insecticide for future use of termite control. Methodology and results: Subterranean termites were collected from mound-building termites found in Universiti Malaysia Terengganu (UMT). Cultivating, harvesting and counting of conidia of EPF were carried out to prepare the desired concentrations for screening test and bioassays, which were 1×103 , 1x105 , 1×107 and control. The pathogenicity testing was observed daily within 1 week under laboratory conditions. Screening showed that M. anisopliae was found to be the most virulent compared to B. bassiana and Paecilomyces sp., achieving 100% mortality within 3-4 days. M. anisopliae was then further tested on termites and it was found that concentration of 1×107 showed the lowest LT50 value, while LC50 of M. anisopliae in 1 day was 2.0151×106 . Conclusion, significance and impact of study: It could be concluded that M. anisopliae is the most virulent EPF against termites and the most effective concentration was ±107 followed by strains of B. bassiana and Paecilomyces sp. However, there is limited field evaluation of EPF against termites in Malaysia. Evaluation on the efficiency of M. anisopliae in the field should be conducted so that its efficacy could be proven and marketed.
ABSTRACT
ABSTRACT: The effects of six diets on biological parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its susceptibility to entomopathogenic fungi Beauveria bassiana (Bb) and Metarhizium anisopliae (Ma) were studied. The diets included a standard diet (bean pods+soybeans, peanuts and sunflower) and diets in which the bean pods were combined with only one type of grain, either soybean, peanut, sunflower, pea or sesame seeds. The best performance was that of insects fed on standard diet, which had the shortest development period and 49.5% of egg-to-adult viability. The insects fed the pea diet exhibited less than 30% viability and 11% of adults had wing deformations. The finite rate of increase values for the treatment groups were: standard: 1.091; soybean: 1.077; peanut: 1.071; sunflower: 1.076; pea: 1.058; and sesame: 1.065. The susceptibility to Ma (55%) was greater than Bb (40%) only for insects fed on the sesame diet. Considering the effects of diet on susceptibility to both fungal species comparatively among the diet-treatment groups, the stink bugs fed the restrictive diets were more susceptible compared with those fed the standard diet. We concluded that diet composition affects the biological parameters of E. heros and differentially affects their susceptibility to Bb and Ma fungi.
ABSTRACT
Este trabalho teve por objetivo avaliar a sensibilidade de isolados dos fungos Metarhizium anisopliae (Metsch.) Sorok. e Beauveria bassiana (Bals). Vuill. ao efeito das radiações solar e ultravioleta e da temperatura. Conídios dos isolados foram expostos, por vários períodos, aos raios de um simulador solar em diversas irradiâncias e a uma lâmpada de raios ultravioleta germicida. Os conídios do isolado de M. anisopliae foram também expostos às temperaturas de 19,5; 24,2 e 31,0ºC, e os do isolado de B. bassiana a 19,4; 20,8 e 28,3ºC, e 18,7; 23,8 e 30,9ºC. Avaliou-se a germinação de conídios pelo teste de viabilidade. Os isolados dos fungos se mostraram bastantes sensíveis aos raios do simulador solar e aos raios ultravioleta. A germinação de ambos sofreu significativa redução a partir de 30 minutos de exposição à radiação do simulador solar. O efeito mais severo foi evidenciado pelo isolado de B. bassiana, com grande redução da germinação dos conídios em todas as irradiâncias testadas. A sensibilidade à radiação ultravioleta também foi grande, pois ocorreu acentuada redução da germinação dos conídios do isolado de M. anisopliae (38,2%) e de B. bassiana (65%) já aos 30 segundos de exposição. A temperatura afetou a viabilidade de ambos os fungos. Temperaturas entre 23,8 e 31ºC favoreceram a germinação dos conídios, enquanto temperaturas próximas de 20ºC dificultaram a germinação.(AU)
This study aimed to access the sensibility of isolates of the fungus Metarhizium anisopliae (Metsch.) Sorok. and Beauveria bassiana (Bals.) Vuill. to the effect of solar and ultraviolet radiation and temperature. Conidia were exposed for various periods to the rays from a solar simulator at various irradiances, and to light germicidal ultraviolet rays. Conidia of the isolate of M. anisopliae were also exposed to temperatures of 19.5, 24.2 and 31.0ºC and the isolate of B. bassiana to 19.4, 20.8 and 28.3ºC, and also to 18.7, 23.8 and 30.9ºC. The germination of conidia was evaluated by the viability test. The fungal isolates showed to be very sensitive to the solar simulator and ultraviolet rays. Germination of both was significantly decreased starting from 30 minutes of exposure to the rays of the solar simulator. The most severe effect was evidenced by the isolate of B. bassiana with great reduction in conidia germination in all the tested irradiances. Sensitivity to ultraviolet radiation was also great, showing a marked reduction in the germination of M. anisopliae (38.2%) and B. bassiana (65%) conidia after 30 seconds of exposure. The temperature affected the viability of both fungi. Temperatures ranging of 23.8 to 31ºC favor the germination of conidia while temperatures around 20ºC constrained germination.(AU)
Subject(s)
Pest Control, Biological , Solar Radiation , Beauveria , Metarhizium , FungiABSTRACT
La Tripanosomiasis americana, también conocida como enfermedad de Chagas, es un padecimiento potencialmente mortal cuyo agente etiológico es el parásito protozoo Trypanosoma cruzi (Chagas 1909 Kinestoplastida: Trypanosomatidae). A pesar de contar con una amplia evidencia clínica se desconocen las cifras de prevalencia en el país ya que para el sistema de salud público mexicano en este momento dicha enfermedad no constituye una prioridad. La existencia de al menos 33 especies de vectores y con elevados índices de infección natural redunda en la aparición de casos positivos que llegan a incluir niños, lo que demuestra una vía activa de transmisión y da fortalezas a criterios de endemicidad. La transmisión del parásito que produce la enfermedad se da a través de varias vías pero en el 33% de los casos se ha reconocido que es por vía vectorial, de allí que el éxito de las campañas de control de los insectos permitirá la disminución drástica del número de infectados. Los métodos de control químico han sido inefectivos debido a problemas operacionales en las campañas y a la falta de integración entre estos, así como a la resistencia de los insectos a los productos.
Subject(s)
Pest Control, Biological , Triatominae , Beauveria , MetarhiziumABSTRACT
Um dos principais problemas enfrentados pelos sericicultores em todo o mundo são entomopatógenos que causam grandes perdas na produção. Destaca-se a doença calcinose branca, causada pelo fungo Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae). Doenças fúngicas são facilmente disseminadas, já que os conídios são transportados pelo ar. Além disso, as condições de temperatura e umidade nos barracões são favoráveis ao surgimento e à manutenção do fungo, aumentando sua incidência. Práticas de higiene como a desinfecção do barracão e de utensílios são recomendadas, no entanto a contaminação das lagartas ainda é frequente. Dessa forma, esse artigo reuniu trabalhos voltados para a pesquisa de produtos antimicrobianos alternativos para o uso em sericicultura.(AU)
Entomopathogens are the most important problem from sericulture all over the world, and cause heavy loss to silkworm crops. Calcinosis is a common disease of silkworm, caused by the pathogenic fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae). Fungal diseases of silkworm are easily spread by spores which are carried through the air. Also, temperature and humidity inside the silkworm rearing rooms are favorable to disease development. Practice hygiene measures during silkworm rearing such as disinfection of rearing houses and appliances are recommended. However, contamination is frequent. This paper presents related research on promising antimicrobiotic products for their use in sericulture industry.(AU)
Subject(s)
Bombyx , Beauveria , Anti-Infective Agents , FungiABSTRACT
This study had the aims of evaluating the antimicrobial characteristics of Stomoxys calcitrans (Diptera: Muscidae) larvae against the fungal isolates CG138, CG228 and ESALQ986 of Beauveria bassiana sensu lato (Balsamo-Crivelli) Vuillemin, 1912 (Hypocreales: Cordycipitaceae). S. calcitrans eggs, larvae and pupae were exposed to these same isolates. Statistical analysis showed that the immature stages of S. calcitrans were not susceptible to the fungal isolates used, regardless of the exposure method. Diffusion test on solid culture medium reveled that macerated S. calcitrans larvae exposed to isolate CG138 reduced CG138 fungal development. The analysis of the chromatographic profiles indicated that the macerate or mucus of larvae of the control group and the groups exposed to the isolate CG138 presented different profiles. Reduced development of the isolate CG138 on the larvae cuticle was observed by means of scanning electron microscopy.
Este estudo teve como objetivos avaliar as características antimicrobianas de larvas de Stomoxys calcitrans (Diptera: Muscidae) contra os isolados CG138, CG228 e ESALQ986 de Beauveria bassiana sensu lato (Balsamo-Crivelli) Vuillemin, 1912 (Hypocreales: Cordycipitaceae). Ovos, larvas e pupas de S. calcitrans foram expostos a estes mesmos isolados. Após análise estatística, foi verificado que os estágios imaturos de S. calcitrans não foram susceptíveis aos isolados utilizados, independentemente do método de exposição utilizado. O teste de difusão em meio sólido mostrou que quando o isolado CG138 foi exposto a macerado de larvas houve redução do desenvolvimento fúngico. A análise dos perfis cromatográficos mostrou que o macerado ou muco de larvas do grupo controle e dos grupos expostos ao isolado CG138 apresentaram diferenças nos perfis. Um desenvolvimento reduzido do isolado CG138 na cutícula de larvas foi observado pela microscopia eletrônica de varredura.
Subject(s)
Animals , Muscidae , Pest Control, Biological/methods , Complex Mixtures/pharmacology , Beauveria/drug effects , Larva , Antifungal Agents/pharmacologyABSTRACT
Este trabajo tuvo por objetivo aislar, identificar y caracterizar morfológicamente hongos entomopatógenos presentes en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.). Se realizó una prospección de hongos entomopatógenos nativos a partir de 40 muestras de suelos cultivados con yerba mate ubicados en la provincia de Misiones, República Argentina, desde mayo de 2008 hasta junio de 2010. Las muestras de suelo se obtuvieron en cercanías de plantas de yerba mate, se aplicó la técnica de dilución seriada en medios de cultivos selectivos. Después de obtenidos los cultivos puros, los hongos fueron caracterizados macroscópica y microscópicamente, y se los identificó mediante el uso de claves taxonómicas específicas. Se aislaron 29 cepas fúngicas pertenecientes a las especies Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) y Purpureocillium lilacinum (n = 10)
This study aimed to morphologically isolate, identify and characterize entomopathogenic fungi present in soils cultivated with Paraguay tea (Ilex paraguariensis). A survey of native entomopathogenic fungi was conducted from 40 soil samples grown with Paraguay tea in the province of Misiones, Argentina, from May 2008 to June 2010. The soil dilution plate methodology on selective culture media was used to isolate microorganisms. Taxonomic identification was performed using macroscopic and microscopic characters and specific keys. Twenty nine strains, belonging to the species Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) and Purpureocillium lilacinum (n = 10) were isolated and identified