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1.
Ticks Tick Borne Dis ; 11(1): 101313, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704209

RESUMO

The present study evaluated, in the laboratory, the virulence of Heterorhabditis bacteriophora LPP30 against engorged females of Rhipicephalus microplus; in addition, we evaluated, in semi-field tests, the effects of four isolates of Heterorhabditis spp. (i.e., H. bacteriophora HP88, Heterorhabditis baujardi LPP7, Heterorhabditis indica LPP1 and H. bacteriophora LPP30) in insect cadaver formulation against the non-parasitic phase of R. microplus. In the first experiment (in vitro), engorged females were exposed, in Petri dish, to H. bacteriophora LPP30 at 75, 150, 300, 600, 1200 and 2400 nematodes/tick (10 ticks per concentration tested). In the second experiment (semi-field), five engorged females and four cadavers of Galleria mellonella infected with nematodes were placed in pots with soil and grown Brachiaria decumbens; the pots were hold outdoor, exposed to natural environment conditions during the tests. In the third experiment (semi-field), 65 days after the cadavers had been placed in the pots for the second experiment, new engorged females (five per pot) were placed in the pots of the groups treated with H. bacteriophora HP88 or H. baujardi LPP7, to assess their persistence in the soil. In the first test, the percent control was higher than 95% in all treatment groups. In the second experiment, at day 22, the mean mortality rate was 78% in the groups treated with H. bacteriophora LPP30 or H. indica LPP1, and reached 100% and 98% when treated with H. bacteriophora HP88 and H. baujardi LPP7, respectively. In this experiment, the egg-laying inhibition index was higher than 90% in the groups treated with H. bacteriophora HP88 (97.2%) or H. baujardi LPP7 (91.9%). In the third experiment with H. bacteriophora HP88 and H. baujardi LPP7, the egg-laying inhibition index was 59.1% and 43.1%, respectively. We concluded that the isolate LPP30 was highly virulent under laboratory conditions, whereas in semi-field tests, HP88 and LPP7 were the most effective isolates. Moreover, HP88 and LPP7 remained active against engorged females of R. microplus in the soil for 65 days after application of EPN-infected cadavers of G. mellonella.


Assuntos
Controle Biológico de Vetores/métodos , Rabditídios/fisiologia , Rhipicephalus , Controle de Ácaros e Carrapatos/métodos , Animais , Cadáver , Mariposas
2.
J Nematol ; 51: 1-7, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31339672

RESUMO

Entomopathogenic nematodes have been evaluated for control of mosquito species for decades. Depending on the nematode and mosquito involved, mortality rates of larvae (L) may reach 100% in vitro. Nonetheless, nematode efficacy at oviposition sites has rarely been assessed. Heterorhabditis indica LPP35 has been shown to kill over 75% of Aedes aegypti L3/L4 in cups and bottles outdoors. To assess its efficacy in indoor oviposition sites, different types/sizes of floor drains and pot saucers, and 65 liter water barrels, were infested with L3/L4 and treated with two doses of infective juveniles (IJs). In floor drains, mortality rates varied from 45 to 82%, with better results in the smallest drains. The adjustable dose of 25 IJs/cm2 of the drain's bottom internal surface gave better results than the fixed dose of 100 IJs/larva. Mortality rates were only 28 to 53% and 0.1 to 1.7% in pot saucers and water barrels, respectively, probably because ridges and grooves that marked the bottom internal surface of these containers hindered the encounter of larvae and IJs.Entomopathogenic nematodes have been evaluated for control of mosquito species for decades. Depending on the nematode and mosquito involved, mortality rates of larvae (L) may reach 100% in vitro. Nonetheless, nematode efficacy at oviposition sites has rarely been assessed. Heterorhabditis indica LPP35 has been shown to kill over 75% of Aedes aegypti L3/L4 in cups and bottles outdoors. To assess its efficacy in indoor oviposition sites, different types/sizes of floor drains and pot saucers, and 65 liter water barrels, were infested with L3/L4 and treated with two doses of infective juveniles (IJs). In floor drains, mortality rates varied from 45 to 82%, with better results in the smallest drains. The adjustable dose of 25 IJs/cm2 of the drain's bottom internal surface gave better results than the fixed dose of 100 IJs/larva. Mortality rates were only 28 to 53% and 0.1 to 1.7% in pot saucers and water barrels, respectively, probably because ridges and grooves that marked the bottom internal surface of these containers hindered the encounter of larvae and IJs.

3.
J Invertebr Pathol ; 165: 22-45, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30940472

RESUMO

Since the 1980s, research into entomopathogenic nematodes (EPNs) in Latin America has produced many remarkable discoveries. In fact, 16 out of the 117 recognized species of EPNs have been recovered and described in the subcontinent, with many more endemic species and/or strains remaining to be discovered and identified. In addition, from an applied perspective, numerous technological innovations have been accomplished in relation to their implementation in biocontrol. EPNs have been evaluated against over 170 species of agricultural and urban insects, mites, and plant-parasitic nematodes under laboratory and field conditions. While much success has been recorded, many accomplishments remain obscure, due to their publication in non-English journals, thesis dissertations, conference proceedings, and other non-readily available sources. The present review provides a brief history of EPNs in Latin America, including current findings and future perspectives.


Assuntos
Agentes de Controle Biológico , Controle de Insetos , Controle Biológico de Vetores , Rabditídios , Agricultura/tendências , Animais , Insetos/parasitologia , Larva/parasitologia , América Latina , Controle Biológico de Vetores/métodos , Controle Biológico de Vetores/tendências , Rabditídios/classificação , Rabditídios/crescimento & desenvolvimento , Rabditídios/isolamento & purificação , Rabditídios/patogenicidade
4.
Ticks Tick Borne Dis ; 10(4): 781-786, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30935855

RESUMO

This work aimed to investigate candidate biological control agents against the cattle tick Rhipicephalus microplus by studying three entomopathogenic nematodes (EPN) isolates from two species, Heterorhabditis bacteriophora (isolates LPP30 and HP88) and Heterorhabditis baujardi (isolate LPP7). The study comprised the pharmacotechnical development of four test formulations, and their biological evaluation, in three stages: 1) selection of the fittest EPN isolate at 16 ± 1 °C after 120 h of incorporation in the formulations; 2) determination of the effects of temperature and incubation time on the survival of the selected isolate in formulations; 3) evaluation of the in vitro efficacy (infectivity) of the selected EPN formulations and their components against R. microplus females after 72 h exposure. H. baujardi LPP7 presented the highest survival rates in 0.1% carboxymethyl cellulose sodium (CMC) formulations (100% at 25 °C, up to 10 days after incorporation). At the highest tested temperature (34.2 °C), 54% of LPP7 survived for up to 72 h in CMC formulations. The infectivity of LPP7-containing formulation against R. microplus was 99%, reducing oviposition, egg production index and larval hatching. Considering the pressing need for safer acaricide products, incorporation of EPNs in pharmaceutical formulations is presented as a promising approach for the biological control of cattle tick infestations, potentially reducing environmental impact and resistance development associated with chemical acaricides.


Assuntos
Agentes de Controle Biológico , Nematoides/fisiologia , Controle Biológico de Vetores/métodos , Rhipicephalus/efeitos dos fármacos , Termotolerância , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Composição de Medicamentos , Feminino , Larva/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/veterinária
5.
Res Vet Sci ; 118: 498-501, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29758533

RESUMO

Porcine pleuropneumonia is an important cause of lowered productivity and economic loss in the pig industry worldwide, associated primarily with Actinobacillus pleuropneumoniae infection. Its colonization and persistence within the upper respiratory tract of affected pigs depends upon interactions between a number of genetically controlled virulence factors, such as pore-forming repeats-in-toxin exoproteins, biofilm formation, and antimicrobial resistance. This study investigated correlations between biofilm-forming capacity, antimicrobial resistance, and virulence of A. pleuropneumoniae obtained from clinical outbreaks of disease, using a Galleria mellonella alternative infection model. Results suggest that virulence is diverse amongst the 21 strains of A. pleuropneumoniae examined and biofilm formation correlated with genetic control of antimicrobial resistance.


Assuntos
Infecções por Actinobacillus/microbiologia , Actinobacillus pleuropneumoniae/efeitos dos fármacos , Actinobacillus pleuropneumoniae/fisiologia , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana , Doenças dos Suínos/microbiologia , Infecções por Actinobacillus/tratamento farmacológico , Animais , Suínos , Doenças dos Suínos/tratamento farmacológico , Virulência
6.
Exp Parasitol ; 179: 28-35, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28655584

RESUMO

This study investigated the possible biological, biochemical and histological changes in Bradybaena similaris(Gastropoda: Pulmonata) infected by Heterorhabditis indica (Rhabditida: Heterorhabditidae), strain LPP1. Two groups of 16 snails were formed: the control group (unexposed) and the treated group, which was exposed for three weeks to infective juveniles (J3) of H. indica LPP1. The experiment was conducted in duplicate, using a total of 64 snails. After the exposure period, the snails were dissected to collect the hemolymph and tissues, for evaluation of the physiological changes caused by the infection. The number of eggs laid/snail and the viability of these eggs were also assessed as indicators of the reproductive activity of B. similaris. Intense glycogenolysis was accompanied by a significant reduction (p < 0.05) in the glucose content of the hemolymph of the exposed snails, indicating that infection by H. indica induces breakdown of the host's glycemic homeostasis. Significant variations (p < 0.05) in the lactate dehydrogenase activity occurred together with changes in the concentration of pyruvic and lactic acid in the hemolymph of the infected B. similaris snails, corroborating the transition from aerobic to anaerobic metabolism in the hosts. These metabolic alterations reflect the parasitic castration process in this interface. The results suggest that the use of H. indica LPP1 is a potential alternative for biological control of B. similaris.


Assuntos
Gastrópodes/parasitologia , Rhabditoidea/fisiologia , Animais , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Galactanos/análise , Gastrópodes/anatomia & histologia , Gastrópodes/metabolismo , Glucose/metabolismo , Glicogênio/metabolismo , Hemolinfa/química , Hemolinfa/enzimologia , Hemolinfa/metabolismo , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/análise , Mariposas/parasitologia , Ácido Pirúvico/análise
7.
Vet Parasitol ; 203(3-4): 310-7, 2014 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-24836639

RESUMO

This study evaluated the efficacy of four entomopathogenic nematode (EPN) strains in insect cadaver formulations against Rhipicephalus microplus and compared the efficacy of the most virulent EPNs applied in cadavers of Galleria mellonella and Tenebrio molitor. In the first experiment, infected G. mellonela larvae were used as the source of EPNs. Engorged females of R. microplus were placed in pots filled with soil and different numbers of G. mellonella larvae infected with one of four species of nematodes. All treatments with EPNs of the genus Heterorhabditis caused significant reduction (p<0.05) in the egg mass weight and hatching percentage of larvae. The EPNs of the genus Steinernema, except for the group exposed to Steinernema carpocapsae ALL, whose source nematodes included six larvae of G. mellonella, caused a significant reduction (p<0.05) in the egg mass weight produced per female. Steinernema feltiae SN applied with two, four, and six cadavers and S. carpocapsae ALL with two cadavers caused a reduction in hatching percentage of larvae of R. microplus (p<0.05). The percentage of control was above 95% in all groups treated with Heterorhabditis bacteriophora HP88 and Heterorhabditis indica LPP1 and in the treatment with four larvae infected with S. feltiae SN. The second experiment followed the same methodology, using G. mellonella and T. molitor larvae infected by the two most virulent EPNs. H. bacteriophora HP88 and H. indica LPP1 in different formulations caused reduction in the egg mass weight and hatching percentage of larvae. The percentage of control were 82.4 and 84.9% for H. bacteriophora HP88 and H. indica LPP1, respectively, formulated in T. molitor, and reaching 99.9% in groups formulated with G. mellonella. The EPNs tested in insect cadaver formulation showed pathogenicity to engorged females of R. microplus and EPNs of the genus Heterorhabditis formulated in G. mellonella larvae were more effective.


Assuntos
Nematoides/fisiologia , Controle Biológico de Vetores , Rhipicephalus/parasitologia , Animais , Feminino , Larva/parasitologia , Mariposas/parasitologia , Contagem de Ovos de Parasitas , Análise de Sobrevida , Tenebrio/parasitologia
8.
Exp Parasitol ; 139: 12-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24566044

RESUMO

Heterorhabditis is a nematode found in the soil that is used as an important biological control agent against various organisms. However, few studies have been performed of its use against snails and the present study is the first to investigate the effect of experimental exposure of Bradybaena similaris to Heterorhabditis indica LPP1. Two groups of 16 snails were formed: the control group (not exposed) and the treatment, which was exposed for three weeks to infective juveniles (J3) of H. indica LPP1. The entire experiment was conducted in duplicate, using a total of 64 snails. After this period, the snails were dissected to collect the hemolymph to evaluate the possible physiological alterations, namely total proteins, uric acid and hemolymph urea, as well as the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as a result of the infection. The terrariums were analyzed on alternate days throughout the experiment to count the dead snails. Intense proteolysis was observed in the infected snails. An increase in the level of uric acid and reduction of the hemolymph urea content indicated that the infection by H. indica results in the inversion of the excretion pattern of the host snail. Variations in the aminotransferase activities were also observed, with the infected group presenting significantly higher values (p<0.05) than the control group for both ALT and AST. The exposure to H. indica LPP1 caused 55% mortality, with the highest rate observed in the first week after exposure (30%). These results suggest that the use of H. indica LPP1 is a feasible alternative for the biological control of B. similaris.


Assuntos
Controle Biológico de Vetores/métodos , Rhabditoidea/fisiologia , Caramujos/parasitologia , Animais , Brasil , Hemolinfa/química , Histocitoquímica , Interações Hospedeiro-Parasita , Larva/parasitologia , Mariposas/parasitologia , Controle Biológico de Vetores/normas , Proteínas/análise , Caramujos/química , Caramujos/fisiologia , Transaminases/análise , Ureia/análise , Ácido Úrico/análise
9.
Exp Parasitol ; 135(2): 466-70, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23994482

RESUMO

Oriental fruit moth Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) is considered a major pest in temperate fruit trees, such as peach and apple. Entomopathogenic nematodes (EPNs) are regarded as viable for pest management control due to their efficiency against tortricid in these trees. The objective of this study was to evaluate the effectiveness of native EPNs from Rio Grande do Sul state against pre-pupae of G. molesta under laboratory and field conditions. In the laboratory, pre-pupae of G. molesta were placed in corrugated cardboard sheets inside glass tubes and exposed to 17 different EPNs strains at concentrations of 6, 12, 24, 48 and 60 IJs/cm(2) and maintained at 25 °C, 70 ± 10% RH and photophase of 16 h. Insect mortality was recorded 72 h after inoculation of EPNs. Steinernema rarum RS69 and Heterorhabditis bacteriophora RS33 were the most virulent strains and selected for field application (LC95 of 70.5 and 53.8 IJs/cm(2), respectively). Both strains were highly efficient under field conditions when applied in aqueous suspension directed to larvae on peach tree trunk, causing mortality of 94 and 97.0%, respectively.


Assuntos
Mariposas/parasitologia , Mariposas/patogenicidade , Controle Biológico de Vetores , Doenças das Plantas/prevenção & controle , Prunus/parasitologia , Rabditídios/patogenicidade , Animais , Brasil , Larva/parasitologia , Larva/patogenicidade , Controle Biológico de Vetores/métodos , Controle Biológico de Vetores/normas , Doenças das Plantas/parasitologia , Distribuição Aleatória , Virulência
10.
Vet Parasitol ; 185(2-4): 364-7, 2012 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-22093907

RESUMO

The aim of this study was to assess the influence of different exposure times of engorged female the Rhipicephalus microplus to infective juveniles of Heterorhabditis bacteriophora isolate HP88. The engorged females were divided into seven groups (six treatments and one control) of 20 ticks each with statistically similar average weights (p>0.05) and exposed to concentrations of 300 nematodes/tick for periods of 3, 6, 12, 24, 48 and 72 h. The following biological parameters were monitored: pre-oviposition period; egg mass weight; hatching percentage; and efficacy of treatment. There was no influence of the exposure time on the pre-oviposition period (p>0.05), while there were significant differences (p<0.05) between the groups exposed for 24, 48 and 72 h and the control group with respect to the egg mass weight, and 24h for hatching percentage. Treatment efficacy reached 100% after exposure for 48 and 72 h. These results demonstrate that infective juveniles of H. bacteriophora HP88, under laboratory conditions, interfere in the majority of the biological parameters of the non-parasitic phase of engorged R. microplus females when the exposure time is greater than or equal to 24h.


Assuntos
Nematoides/fisiologia , Rhipicephalus/parasitologia , Animais , Feminino , Interações Hospedeiro-Parasita , Controle Biológico de Vetores
11.
J Invertebr Pathol ; 107(2): 164-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21514301

RESUMO

Two assays were conducted to assess the influence of infective juveniles (IJs) of Heterorhabditis baujardi LPP7 on the embryogenesis and hatching of Meloidogyne mayaguensis. In the first assay, eggs were incubated in water alone or in the presence of infective juveniles, and completion of embryogenesis was evaluated 14days later. In the second assay, unhatched second-stage juveniles were incubated in distilled water alone or in the presence of infective juveniles. Cumulative hatching was compared at various time intervals. Embryogenesis was not affected, whereas second-stage juveniles hatching was delayed probably because of the eggs permeability to noxious metabolites released by Photorhabdus luminescens, which is the bacterial symbiont of H. baujardi.


Assuntos
Embrião não Mamífero/embriologia , Interações Hospedeiro-Parasita , Controle Biológico de Vetores , Infecções por Rhabditida/fisiopatologia , Rhabditoidea/crescimento & desenvolvimento , Animais , Bioensaio , Embrião não Mamífero/fisiologia , Óvulo/fisiologia , Reprodução
12.
Vet Parasitol ; 170(3-4): 355-8, 2010 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-20227185

RESUMO

The objective of this work was to evaluate the effect of different concentrations of the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora strain HP88 on the biological parameters of the non-parasite phase of engorged females of the cattle tick Rhipicephalus (Boophilus) microplus. Six groups were formed, each containing 20 engorged females, which were exposed to the following concentrations of infective juveniles of this nematode: 0, 75, 150, 300, 600 and 1200 EPNs/female, respectively. The following biological parameters were observed: female weight before oviposition, egg mass weight, pre-oviposition period, oviposition period, survival period, hatching percentage, egg production index (%EPI), nutritional index (%NI) and efficacy of treatment. There were no statistically significant differences in the female weight before the oviposition and pre-oviposition period (p>0.05) between the groups. The nematode action caused significant alterations (p<0.01) in the egg mass weight, oviposition period, survival period, hatching percentage, %EPI and %NI between the treated groups and the control group. Treatment efficacy was higher than 90% in all groups, reaching 99% at a dosage of 1200 EPNs/female. The present study demonstrates that under laboratory conditions, H. bacteriophora HP88 has a deleterious effect on the majority of the parameters of the non-parasitic phase of engorged R. (B.) microplus females, making this species a potential biological control agent of cattle ticks.


Assuntos
Nematoides/fisiologia , Rhipicephalus/parasitologia , Controle de Ácaros e Carrapatos/métodos , Animais , Feminino , Interações Hospedeiro-Parasita , Oviposição , Óvulo , Controle Biológico de Vetores/métodos
13.
J Invertebr Pathol ; 102(1): 6-13, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19460384

RESUMO

Laboratory, greenhouse, and field experiments were performed with the objective of selecting efficient indigenous strains of entomopathogenic nematodes (EPNs) from Rio Grande do Sul (RS) state, Brazil, for controlling the South American fruit fly, Anastrepha fraterculus (Wied.). Laboratory experiments were conducted in 24 well-plates filled with sterile sand and one insect per well. In greenhouse experiments, plastic trays filled with soil collected from the field were used, while in field experiments, holes were made in soil under the edge of peach tree canopies. Among 19 EPN strains tested, Heterorhabditis bacteriophora Poinar RS88 and Steinernema riobrave Cabanillas, Poinar, & Raulston RS59 resulted in higher A. fraterculus larval (pre-pupal) and pupal mortality, with LD(90) of 1630, 457 and 2851, 423 infective juveniles (IJs)/cm(2), respectively. Greenhouse experiments showed no differences in pupal mortality at 250 and 500IJs/cm(2) of either nematode. In the field, H. bacteriophora RS88 and S. riobravae RS59 sprayed individually over natural and artificially infested fruit (250IJs/cm(2)) resulted in A. fraterculus larval mortality of 51.3%, 28.1% and 20%, 24.3%, respectively. There was no significant difference in A. fraterculus pupal mortality sprayed with an aqueous suspension of either nematode; however, when using infected insect cadavers, H. bacteriophora RS88 was more efficient than S. riobrave RS59. Our results showed that H. bacteriophora RS88 was more virulent to insect larvae, with an efficient host search inside the infested fruit and control of pupae in the soil after being applied by aqueous suspension or infected cadavers.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Nematoides/fisiologia , Controle Biológico de Vetores/métodos , Prunus/microbiologia , Tephritidae/parasitologia , Animais , Brasil
14.
Mem Inst Oswaldo Cruz ; 103(2): 150-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18425267

RESUMO

Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondônia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.


Assuntos
DNA de Helmintos/análise , Rabditídios/isolamento & purificação , Solo/parasitologia , Animais , Brasil , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Rabditídios/anatomia & histologia , Rabditídios/classificação , Rabditídios/genética , Árvores , Clima Tropical
15.
Mem. Inst. Oswaldo Cruz ; 103(2): 150-159, Mar. 2008. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-480640

RESUMO

Despite massive losses of primary forest, the Amazonian rainforest remains an extremely rich source of biodiversity. In recent years, entomopathogenic nematodes (EPNs) have been isolated from soil in various parts of the world and used successfully as biological control agents against numerous insect pests. Therefore, a sampling in the rainforest of Monte Negro, Rondônia, Brazil was conducted with the aim of discovering new strains and/or species of EPNs for future development as biological control agents. From 156 soil samples taken at nine collecting sites, 19 isolates were obtained, all of them belonging to the genus Heterorhabditis. Four strains were subjected to detailed morphological and molecular evaluation. Based on morphometrics and internal transcribed spacer (ITS) sequence data, the strains LPP1, LPP2 and LPP4 were identified as Heterorhabditis indica, whereas LPP7 was considered Heterorhabditis baujardi. Comparative analysis of the ITS1 sequence of H. indica and H. baujardi isolates showed a polymorphic site for the restriction enzyme Tth 111 that could be used to distinguish the two species. Consequently, strains LPP1, LPP2, LPP3, LPP4, and LPP9 were identified as H. indica, whereas LPP5, LPP7, LPP8 and LPP10 were identified as H. baujardi.


Assuntos
Animais , Masculino , DNA de Helmintos/análise , Rabditídios/isolamento & purificação , Solo/parasitologia , Brasil , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Rabditídios/anatomia & histologia , Rabditídios/classificação , Rabditídios/genética , Árvores , Clima Tropical
16.
Neotrop Entomol ; 36(2): 161-79, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17607448

RESUMO

A multitude of insects and mites attack fruit crops throughout the tropics. The traditional method for controlling most of these pests is the application of chemical pesticides. Growing concern on the negative environmental effects has encouraged the development of alternatives. Inundatively and inoculatively applied microbial control agents (virus, bacteria, fungi, and entomopathogenic nematodes) have been developed as alternative control methods of a wide variety of arthropods including tropical fruit pests. The majority of the research and applications in tropical fruit agroecosystems has been conducted in citrus, banana, coconut, and mango. Successful microbial control initiatives of citrus pests and mites have been reported. Microbial control of arthropod pests of banana includes banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae) (with EPNs and fungi) among others Oryctes rhinoceros (L.) is one of the most important pests of coconut and one of the most successful uses of non-occluded virus for classical biological control. Key pests of mango that have been controlled with microbial control agents include fruit flies (Diptera: Tephritidae) (with EPNs and fungi), and other pests. Also successful is the microbial control of arthropod pests of guava, papaya and pineapple. The challenge towards a broader application of entomopathogens is the development of successful combinations of entomopathogens, predators, and parasitoids along with other interventions to produce effective and sustainable pest management.


Assuntos
Artrópodes , Frutas , Controle Biológico de Vetores , Árvores/parasitologia , Animais , Clima Tropical
17.
J Invertebr Pathol ; 96(2): 187-92, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17532003

RESUMO

Interactions between the nematode Heterorhabditis bacteriophora isolate JPM4 and the fungus Metarhizium anisopliae, isolates LPP45 and LPP39, were studied during dual infections of Diatraea saccharalis. Mortality, production of infective juveniles (IJs) and production of conidia were evaluated. A positive effect was demonstrated for host mortality in duel infections of JPM4 and LPP39, causing 100% mortality with LT(50) and LT(95) values of 1.8 and 2.8 days, respectively. Higher values were seen when using the nematode or fungi individually. However, a combination of JPM4+LPP39 caused a significant reduction in IJ production. The results show that faster time to death, a moderately virulent fungal isolate could be combined with the nematode, however at the expense of IJ production.


Assuntos
Lepidópteros/microbiologia , Lepidópteros/parasitologia , Metarhizium/patogenicidade , Rhabditoidea/patogenicidade , Animais , Controle Biológico de Vetores , Saccharum , Esporos Fúngicos/patogenicidade , Virulência
18.
Neotrop. entomol ; 36(2): 161-179, Mar.-Apr. 2007. ilus
Artigo em Inglês | LILACS | ID: lil-454494

RESUMO

A multitude of insects and mites attack fruit crops throughout the tropics. The traditional method for controlling most of these pests is the application of chemical pesticides. Growing concern on the negative environmental effects has encouraged the development of alternatives. Inundatively and inoculatively applied microbial control agents (virus, bacteria, fungi, and entomopathogenic nematodes) have been developed as alternative control methods of a wide variety of arthropods including tropical fruit pests. The majority of the research and applications in tropical fruit agroecosystems has been conducted in citrus, banana, coconut, and mango. Successful microbial control initiatives of citrus pests and mites have been reported. Microbial control of arthropod pests of banana includes banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae) (with EPNs and fungi) among others Oryctes rhinoceros (L.) is one of the most important pests of coconut and one of the most successful uses of non-occluded virus for classical biological control. Key pests of mango that have been controlled with microbial control agents include fruit flies (Diptera: Tephritidae) (with EPNs and fungi), and other pests. Also successful is the microbial control of arthropod pests of guava, papaya and pineapple. The challenge towards a broader application of entomopathogens is the development of successful combinations of entomopathogens, predators, and parasitoids along with other interventions to produce effective and sustainable pest management.


Muitos insetos e ácaros atacam fruteiras nos trópicos. O método tradicional para controlar a maioria dessas pragas é a aplicação de inseticidas químicos. A crescente preocupação sobre os efeitos negativos desses produtos vem encorajando o desenvolvimento de alternativas. Agentes do controle biológico aplicados de forma inundativa ou inoculativa têm sido pesquisados como método de controle alternativo para uma variedade de pragas em grande número de culturas, incluindo fruteiras tropicais. A maioria das pesquisas e aplicações em fruteiras tropicais tem sido feita em citros, banana, côco e manga. Especificamente, há vários casos de sucesso em citros para diferentes ácaros e insetos. Em banana, o controle do moleque-da-bananeira, Cosmopolites sordidus Germar (Coleoptera: Curculionidae) com nematóides e fungus também é considerado de sucesso. Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae) é uma das principais pragas em côco e um dos mais importantes exemplos de controle biológico clássico por vírus não-ocluso. As pragas-chave em manga que têm sido controladas com diferentes agentes de controle microbiano são as moscas-das-frutas (Diptera: Tephritidae), com nematóides e fungos, o gorgulho-da-manga, Sternochetus mangiferae (Fabricius) (Coleoptera: Curculionidae), com fungos, e vários hemípteros com fungo. O controle microbiano de pragas tem sido bem sucedido também em goiaba, mamão e abacaxi. O desafio que se vislumbra para a maior aplicabilidade dessas tecnologias é o desenvolvimento de combinações compatíveis entre entomopatógenos, predadores e parasitóides juntamente com outras técnicas de controle.


Assuntos
Animais , Artrópodes , Frutas , Controle Biológico de Vetores , Árvores/parasitologia , Clima Tropical
19.
Nutrire Rev. Soc. Bras. Aliment. Nutr ; 31(2): 61-73, 2006. tab
Artigo em Português | LILACS | ID: lil-455668

RESUMO

Twenty-nine fruits commonly consumed in Brazil were analyzed for mineral composition. Na and K levels were determined by flame photometric procedure and Ca, Mg, Fe, Zn, Cu and Se levels by atomic absorption spectrometry, with organic matter wet oxidation. The results were compared with data from Mexican, American and Brazilian food chemical composition tables. Each fruit was classified as a source of Ca, Mg, Fe, Zn, Cu and Se or not a source of such elements, according to the DRI (Dietary Reference Intakes) and also as a source of Na and K or not a source of such elements according to the RDA (Recommended Dietary Allowance). In general, the mineral levels were lower than those resented in the Brazilian table and there were small differences between the data obtained in this study and the values reported in the literature


Assuntos
Análise de Alimentos , Composição de Alimentos , Frutas , Minerais , Espectrofotometria Atômica/métodos , Fotometria/métodos
20.
Braz. arch. biol. technol ; 48(6): 911-919, Nov. 2005. tab, graf
Artigo em Inglês | LILACS | ID: lil-420441

RESUMO

Fêmeas ingurgitadas e parcialmente ingurgitadas de B. microplus foram expostas a 600, 3000, 6000 e 30000 juvenis infectivos de Steinernema carpocapsae Weiser, 1955 linhagens Santa Rosa e ALL por placa, sob condições de laboratório. Foram investigados para fêmeas ingurgitadas: peso da massa de ovos, período pré-postura, período de postura, tempo de sobrevivência, índice de eficiência reprodutiva, percentual de aclosão de larvas e concentrações letais 50% e 90% (CL50 e CL90). Para fêmeas parcialmente ingurgitadas somente foram observados peso da massa de ovos, tempo de sobrevivência, CL50 e CL90. Todos os parâmetros biológicos de fêmeas ingurgitadas foram e parcialmente ingurgitadas foram alterados pela exposição a juvenis infectivos de S. carpocapsae linhagens Santa Rosa e ALL (P<0,05). O aumento das resposta foi diretamente proporcional ao aumento das concentrações de juvenis infectivos por placa (P<0,05). Os resultados sugerem que nematóides entomopatogênicos podem ter papel primissor no controle de carrapatos dos bovinos.

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