Resumen El control biológico en caña de azúcar en Venezuela se ha logrado establecer como una medida única, con resultados óptimos del uso de parasitoides y entomopatógenos para el control de los taladradores del género Diatraea, y, posteriormente, de la candelilla Aeneolamia spp., ambas plagas claves del cultivo. Para los taladradores, se logró después de liberaciones sistemáticas de la mosca amazónica Lydella minense desde un inicio, a mediados del siglo XX y luego con el establecimiento de la avispa bracónida Cotesia flavipes, a partir de 1987. Para el control biológico de Aeneolamia varia, plaga que implicaba la aplicación frecuente de insecticidas, después de la introducción del uso del hongo entomopatógeno Metarhizium anisopliae desde 1977, se ha establecido como medida eficiente para el control de sus adultos, aunque las ninfas eran menos controladas. Este aspecto se resolvió mediante la introducción del nematodo entomopatógeno Heterorhabditis bacteriophora en 2004, el cual se viene utilizando en forma general, y prácticamente ya se tienen las medidas biológicas para evitar la aplicación de insecticidas. Como ejemplo se tiene a la Azucarera Río Turbio, aunque en las últimas zafras ha tenido una reducción en sus áreas, por diferentes factores. Durante los últimos 58 años, la infestación de Diatraea muestra una reducción de 15 a 3.18 %, con lo cual se salvan 170 552.62 toneladas métricas (TM), con un valor de US$ 49 196 045 y un costo del control biológico de US$ 1 187 189 lo que se traduce en un beneficio-costo de US$ 41.44. Antes del establecimiento del control biológico, Aeneolamia se controlaba exclusivamente con insecticidas químicos, aplicados al follaje para los adultos y al suelo para las ninfas. Simultáneamente desde entonces, se ha utilizado el hongo M. anisopliae producido por empresas nacionales, hasta cubrir 87 000 ha, entre 1986 y 1990. También, desde 2004 se inició la utilización de nematodos entomopatógenos para el control de ninfas de Aeneolamia.

Abstract The biological control in sugarcane in Venezuela has been established as a unique measure, having optimal results of the use of parasitoids and entomopathogens for the control of borers of the genus Diatraea, and later of the candelilla Aeneolamia spp., both key pests of the crop. For borers it was achieved after systematic releases of the Amazonian fly Lydella minense from the middle of the last century and then with the establishment of the braconid wasp Cotesia flavipes from 1987. For the biological control of Aenolamia varia, pest that involved the frequent application of insecticides, after the introduction of the use of the entomopathogenic fungus Metarhizium anisopliae since 1977, has been established as an efficient measure for the control of its adults, however, the nymphs were less controlled. This aspect was resolved through the introduction of the entomopathogenic nematode Heterorhabditis bacteriophora in 2004, which has been widely used as a biological measure to avoid the application of insecticides. As an example, we have the Azucarera Río Turbio, although in the last harvests it has had a reduction in its areas due to different factors. During the last 58 years, Diatraea infestation shows a reduction of 15 to 3.18 %, which saves 170 552.62 metric tons with a value of US$ 49 196 045 and a cost of biological control of US$ 1 187 189 which translates into a benefit-cost of US$ 41.44. Before the establishment of biological control, Aeneolamia was controlled exclusively with chemical insecticides applied to foliage for adults and soil for nymphs. Simultaneously since then, the entomopathogenic fungus M. anisopliae produced by national companies has been used and this entomopathogen was used on 87 000 hectares between 1986 and 1990. Also since 2004, the methodology of using entomopathogenic nematodes to control Aeneolamia nymphs began.

ABSTRACT Integrated management is considered the best strategy to mitigate the damage caused by plant-parasitic nematodes. However, there is still limited information regarding some integrated techniques. Thus, this study aimed to assess the effects of genetic management associated with chemical control of Meloidogyne javanica in soybean (Glycine max (L.) Merr.) The experiment was installed in a greenhouse according to an 8×4 factorial design with eight replicates. The first factor was soybean cultivar (HO Juruena IPRO, resistant; Foco IPRO, HO Maracaí IPRO, and CZ 58B28 IPRO, moderately resistant; HO Mamoré IPRO, moderately susceptible; and Extrema IPRO, CZ 48B32 IPRO, and HO Aporé IPRO, susceptible). The second factor consisted of an untreated control and commercial nematicides based on abamectin, thiodicarb+imidacloprid, and fluopyram. Plants were inoculated with 2000 nematode eggs, and nematode and vegetative variables were evaluated at 65 d after inoculation. There was an interaction effect on nematode variables. Furthermore, there was an additive effect of genetic management and chemical control, mainly in resistant cultivars treated with thiodicarb+imidacloprid or fluopyram with controls of up to 69.90% and 96.86%, respectively. The application of fluopyram and the use of ‘HO Juruena IPRO’, ‘Foco IPRO’, or ‘HO Maracaí IPRO’ also contributed to the control of M. javanica. Vegetative variables were studied by analyzing product effects separately, but results were inconclusive.

Abstract Phytopathogenic nematodes are a threat for agriculture, they cause plant diseases and economic losses worldwide. Currently, the pursuit of compounds of biological origin for nematode biocontrol has become a priority as an environmentally friendly alternative. Microorganisms-derived compounds have several strategies to reduce the populations of infectious juvenile nematodes. Although microorganisms and their metabolites are the focus of literature reports reviews on nematicidal control, interactions between fungi, bacteria, and nematodes, as well as the compounds that are generated in such interactions, are not highlighted. The aim of this review was to discuss the latest advances on chemical compounds secreted by microorganisms and their interaction mechanisms for biological control of phytopathogenic nematodes. Results were organized based on: i) mode of action, ii) infection process, iii) nematicide compounds, iv) interactions and field applications, and v) current challenges. The scope of this review contributes to a better comprehension of the versatility of bacterial and fungal compounds for their use in the development of management plans for nematode control.

Resumen Los nematodos fitopatógenos son una amenaza para la producción agrícola, causando enfermedades en las plantas y pérdidas económicas en todo el mundo. En la actualidad, la búsqueda de compuestos de origen biológico para estos nematodos, como una alternativa amigable con el ambiente, se ha convertido en prioridad. Los compuestos derivados de microorganismos cuentan con diferentes mecanismos de acción para reducir las poblaciones de juveniles infecciosos de nematodos. A pesar de que la literatura reporta revisiones sobre los microorganismos y sus metabolitos nematicidas, no se destacan las interacciones entre hongos, bacterias y nematodos, así como de los compuestos que se generan en tales interacciones. El objetivo de esta revisión fue discutir los avances recientes sobre compuestos químicos secretados por microorganismos y mecanismos de interacción para el control biológico de nematodos fitopatógenos. Los resultados se organizaron en función de i) mecanismos de acción, ii) proceso de infección, iii) compuestos nematicidas, iv) interacciones y aplicaciones a las soluciones en campo y v) desafíos actuales. El enfoque de esta revisión contribuye a una mejor comprensión de la utilidad de los compuestos producidos por bacterias y hongos que permitan incorporarlos en el desarrollo de planes de manejo para el control de nematodos.

Abstract Root-knot nematodes are detrimental to agricultural crops and hard to control once established in the field. The objective of this research was to evaluate the growth, sporulation, and capture in vitro of asexual fungi against Meloidogyne sp. Molecular identification of the asexual fungi included in the study was performed by sequencing the ITS1 region of rDNA. The growth and sporulation of Arthrobotrys sp., Dactylellina sp. and Dactylaria sp. was evaluated in five culture media and two types of substrates (rice husks and ground corn). For the evaluation of attraction and capture of the nematodes, second stage juveniles of Meloidogyne sp. All the evaluated fungal isolates grew and sporulated in the culture media and substrates. The fungi Arthrobotrys sp. (C19-1-1) and Dactylellina sp. (C19-48) showed greater effectiveness in attracting and capturing Meloidogyne sp. The evaluated fungal isolates have the potential to colonize different culture media and substrates. In addition, they can form modified and specialized hyphae that control juvenile Meloidogyne sp. nematodes. Therefore, future studies should focus on evaluating fungal isolates against root-knot nematodes under field conditions.

Resumen Los nematodos formadores de agallas son perjudiciales para los cultivos agrícolas. El objetivo de esta investigación fue evaluar el crecimiento, esporulación y captura de hongos asexuales contra Meloidogyne sp. en condiciones in vitro. La identificación molecular de los hongos asexuales se realizó con PCR utilizando secuencias de la región ITS del ADNr. Se evaluó el crecimiento y esporulación de Arthrobotrys, Dactylellina y Dactylaria en cinco medios de cultivos y dos tipos de substratos (cascarilla de arroz y maíz molido). Para la evaluación de atracción y captura de los nematodos se emplearon juveniles de segunda etapa de Meloidogyne sp. Todos los aislamientos fúngicos evaluados crecieron y esporularon en los medios de cultivos y substratos. Los hongos Arthrobotrys sp. (C19-1-1) y Dactylellina sp. (C19-48) mostraron mayor efectividad en la atracción y captura de Meloidogyne sp. Los aislamientos fúngicos evaluados tienen el potencial de colonizar diferentes medios de cultivos y substratos. Además, pueden formar hifas modificadas y especializadas que controlan nematodos juveniles de Meloidogyne sp. Por lo tanto, los futuros estudios se deberían centrar en evaluar los aislados fúngicos contra los nematodos formadores de agallas en condiciones de campo.

Resumo O nematoide-das-galhas Meloidogyne incognita está entre os fatores bióticos que afetaram enormemente a produção e a qualidade da cultura do tomate. O nematoide parasita de ovos, Purpureocillium lilacinum (Pl), é considerado um dos mais promissores agentes no controle e superação desse fitopatógeno. O efeito nematicida do isolado nativo Pl AUMC 10149 na sobrevivência de juvenis de segundo estágio e na eclosão dos ovos de M. incognita em diferentes momentos de exposição foi testado in vitro. Os dados obtidos mostraram que o Pl deu um percentual máximo de mortalidade de J2 (97.6%) e inibição da eclosão dos ovos (79.8%) após 72 horas de exposição. A potencialidade de Pl e de Bio-Nematon para controlar M. incognita infectando tomate foi conduzida em diferentes tempos de aplicação in vivo. Nove tratamentos com cinco repetições foram usados para tais bioagentes em comparação com o nematicida Oxamyl. Cada muda foi inoculada com 1.000 J2s de nematoide / vaso e 10 mL de Pl (1×1010 CFU/mL). Ou suspensão de esporos Bio-Nematon (1×108 CFU/mL) 10mL/pot. Os resultados indicaram que os tratamentos mais eficazes na redução da população de nematoides, número de galhas e desovas de M. incognita nas raízes das plantas foram realizados com Pl pré-plantio e pós-infecção com Pl (Rf 1.9), dando um aumento significativo no comprimento da planta (64.9%), massa fresca (72.52%) e massa seca da parte aérea (163.41%) sem impactar negativamente o meio ambiente. Portanto, o presente estudo confirmou que o uso de P. lilacinum AUMC 10149 pode ser usado como um suplemento prático para o manejo ecologicamente correto de nematoides-das-galhas no Egito.

Abstract Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile’s survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.

Resumo O Brasil é o maior produtor de figos da América do Sul, porém o cultivo comercial brasileiro da figueira baseia-se na plantação de uma única cultivar, o Roxo-de-Valinhos, resultando em sérios problemas relativos a pragas e doenças. Uma vez que há variações epigenéticas na interação planta-patógeno, principalmente por meio da regulação gênica, o presente trabalho objetiva realizar a caracterização in vivo de acessos de figo, por meio da análise de incidência natural de nematoides formadores de galha e de incidência natural de ferrugem, correlacionada ao seu perfil epigenômico, a fim de subsidiar trabalhos de conservação, melhoramento genético e produção da cultura. A análise dos componentes principais dos dados da caracterização dos acessos foi realizada por meio da matriz de correlação residual obtida pela análise de variância conjunta utilizando o programa GENES. Pôde-se constatar que todas as plantas foram atacadas por este patógeno, evidenciando que são suscetíveis ao mesmo. Já a análise conjunta dos dados demonstrou que a metilação e a incidência de ferrugem em folhas, quando observadas na mesma fase fenológica da planta, se correlacionam, apresentando evidências iniciais de mesmas cargas fatoriais de pressão nos genótipos, com a premissa de comportamento semelhante nos mesmos, indicando que, além do fator genético, fatores abióticos também são responsáveis pelas alterações no fenótipo das plantas, evidenciando a plasticidade fenotípica das mesmas.

Abstract Commercial fig tree cultivation in Brazil involves a single cultivar, ‘Roxo-de-Valinhos’. The use of a single cultivar results in serious diseases and related problems. The aim of this study was to characterize fig accessions by analyzing the natural root-knot nematode and leaf rust incidence in relation to the epigenomic profile of the plant, since epigenetic variations affect plant–pathogen interactions. All plants were attacked by nematodes, indicating susceptibility; Meloidogyne incognita was the root-knot nematode species involved. Joint analysis of data showed that methylation and leaf rust incidence were correlated when observed in the same phenological phase, presenting initial evidence of the same factorial pressure loads in genotypes, suggesting similar behavior within these genotypes.

Resumo Nematoides entomopatogênicos (NEP) das famílias Heterorhabditidae e Steinernematidae são amplamente utilizados no controle de insetos-pragas. No Brasil, os estudos relacionados a caracterização e identificação destes entomopatógenos são recentes e escassos. Nesse sentido, o objetivo deste estudo foi isolar NEP de amostras de solos coletadas em diferentes áreas no estado do Paraná, Brasil. Um isolado Heterorhabditis (UEL 08) detectado em amostra de solo em área de pastagem cultivada com braquiária, localizada em Londrina, Paraná, Brasil (23º34´311´´S, 050º58´298´´W), utilizando o método de “inseto-isca” com lagartas de Galleria mellonella. Para a identificação foram realizados estudos de morfometria e identificação molecular a partir da amplificação da região ITS. Algumas diferenças foram encontradas em termos de morfometria em comparação com a descrição original, entretanto, os dados moleculares demonstraram que a sequência obtida para o isolado UEL 08 é idêntica à sequência de referência de H. amazonensis (DQ665222), com a qual apresentou 100% de similaridade. Os estudos das características biológicas de H. amazonensis (UEL 08) revelaram que o isolado tem dois ciclos de vida distintos, um curto (216 h) e outro longo (288 h), sendo que ocorrem duas gerações em ambos os ciclos. O isolado UEL 08 H. amazonensis foi patogénico e virulento sobre os três hospedeiros avaliados. Notadamente, as larvas de G. mellonella e Alphitobius diaperinus foram consideradas mais susceptíveis do que os adultos do percevejo Dichelops (Diacereus) melacanthus, com percentagens de mortalidade de 100%, 85% e 46% de mortalidade, respectivamente. O ensaio de produção in vivo revelou um rendimento médio diário de 3,4 × 103 juvenis infectantes/g de larva hospedeira.

Abstract Entomopathogenic nematodes (EPNs) from Heterorhabditidae and Steinernematidae families are extensively used to control insect pests. In Brazil, however, relatively few studies have identified and characterized these entomopathogens. The objective of this study was to identify and characterize an EPN isolate obtained from soil samples collected in the state of Paraná, Brazil. An isolate (UEL 08) of Heterorhabditis was detected in a soil sample collected from a pasture area cultivated with Brachiaria grass in Londrina, state of Paraná, Brazil (23°34ʹ311ʹʹS, 050°58ʹ298ʹʹW), using the insect-baiting technique with Galleria mellonella larvae as hosts. The nematode was identified through morphometric studies and molecular analyses based on amplification of the rDNA ITS region. Although we identified certain morphometric differences compared with the original description, the molecular data indicated that the ITS sequence obtained for the UEL 08 isolate is identical to the reference sequence of H. amazonensis (DQ665222) and presented 100% similarity. Thus, the findings of our morphological and molecular studies confirmed that the isolated nematode is H. amazonensis, which is the first time this species has been registered in Paraná. Study of the biological characteristics of H. amazonensis (UEL 08) revealed that the isolate has two distinct life cycles – one short (216 h) and the other long (288 h) – and produces two generations in both cycles. We observed that H. amazonensis (UEL 8) was pathogenic and virulent to the three evaluated hosts, although with different virulence against these hosts. The larvae of G. mellonella and Alphitobius diaperinus were more susceptible than adult Dichelops (Diacereus) melacanthus, with 100%, 85%, and 46% mortality, respectively. Furthermore, an in vivo production assay revealed a mean daily yield of 3.4 × 103 infective juveniles/g host larvae.

ABSTRACT Root-knot nematodes cause a significant reduction in the productivity of the gilo due to physiological stress. Incorporating organic residue into the soil has a positive effect in reducing nematode infestation. The aim of this study was to evaluate the effect of the addition of organic residue on the reproduction of Meloidogyne javanica and its role in the physiology of the gilo. One-litre pots, each containing one gilo seedling, were inoculated with 5000 eggs of M. javanica and the following treatments evaluated: 1) no inoculation and no residue (NIR); 2) NIR; 3) 12.5 g L-1 poultry manure; 4) 25 g L-1 cattle manure; 5) 20 g L-1 filter cake; 6) 5 g L-1 of the shoots of Tagetes patula; 7) 6.25 g L-1 of the shoots of Brassica oleracea var. capitata; 8) 20 mL L-1 vinasse and 9) 1 mL Abamectin-based commercial product (18 g L-1 a.i.). A randomised block design was used, with six repetitions. Gas exchange variables were evaluated 15, 30 and 45 days after inoculation with the nematode (DAI) and the vegetative and nematological variables at 60 DAI. The treatments that included cattle manure and filter cake afforded the best physiological rate and development in the gilo. The best results in controlling the nematode were given by the poultry manure, cattle manure and filter cake, reducing the reproduction of M. javanica by 41.76, 51.44 and 52.40%, respectively. Based on the results, poultry manure, cattle manure and filter cake are efficient in controlling M. javanica and show potential to be used in the integrated management of M. javanica in the gilo.

Resumo Oesophagostomum venulosum é um nematoide gastrointestinal (GIN) cujos hospedeiros são principalmente ovinos e caprinos. Na Argentina, a presença deste parasito é relatada em todas as regiões do país, principalmente em ovinos. No Noroeste Argentino (NOA) é relatado em bovinos e camelídeos. O objetivo deste trabalho é descrever pela primeira vez a presença de O. venulosum em caprinos da região NOA. Em março de 2023, o Serviço Especializado em Diagnóstico Veterinário realizou uma visita diagnóstica a um estabelecimento de criação de caprinos da raça Criolla, localizado próximo à cidade de Salta Capital, província de Salta, Argentina. O motivo da visita deveu-se ao óbito de uma cabra que, segundo relato do proprietário, antes de sua morte, apresentava quadro de cólicas, dispnéia com perda progressiva da condição corporal. Diante da suspeita de quadro parasitário, optou-se pela coleta do trato digestivo para determinação de espécimes adultos. A presença de Haemonchus contortus e Trichostrongyluscolubriformis pôde ser observada no abomaso e no intestino delgado, respectivamente. Já no cólon foi observada a presença de O. venulosum. A descoberta de O. venulosum nesta espécie vem somar-se aos relatos do referido NGI em outras espécies no NOA, sendo esta a primeira descrição deste tipo em caprinos a nível nacional.

Resumen Oesophagostomum venulosum es un nematodo gastrointestinal (NGI) que tiene como hospedadores principalmente a los ovinos y caprinos. En Argentina la presencia de este parásito está informada en todas las regiones del país, principalmente en la especie ovina. En el Noroeste Argentino (NOA) está reportado en bovinos y camélidos. El objetivo de este trabajo fue describir por primera vez la presencia de O. venulosum en caprinos de la región del NOA. En marzo de 2023, el Servicio de Diagnóstico Veterinario Especializado INTA Salta, realizó una visita diagnóstica a un establecimiento de cría caprino de raza Criolla, ubicado en las cercanías de la ciudad capital de Salta, Argentina. El motivo de la visita fue por la muerte de una cabra que, según el relato del propietario, previo a su muerte presentó un cuadro de cólico y disnea, con pérdida progresiva de la condición corporal. Ante la sospecha de un cuadro parasitario, se decidió recolectar el tracto digestivo para la determinación de especímenes adultos. Se pudo observar la presencia de Haemonchus contortus en el abomaso, de Trichostrongylus colubriformis en el intestino delgado, y de O. venulosum en el colon. El hallazgo de O. venulosum en caprinos se suma a los informes de dicho NGI en otras especies de animales de interés zootécnico del NOA, y es, hasta nuestros conocimientos, la primera descripción en caprinos a nivel nacional.

Abstract Oesophagostomum venulosum is a gastrointestinal nematode (GIN) whose hosts are mainly sheep and goats. In Argentina, the presence of this parasite is reported in all regions of the country, mainly in sheep. In the Argentine Northwest (NOA) it is reported in cattle and camelids. The objective of this work was to describe for the first time the presence of O. venulosum in goats from the NOA region. In March 2023, the INTA Salta Specialized Veterinary Diagnostic Service made a diagnostic visit to a Criolla breed goat breeding facility, located near the capital city of Salta, Argentina. The reason for the visit was due to the death of a goat that, according to the account of the owner, prior to her death, presented symptoms of colic and dyspnea, with progressive loss of body condition. Given the suspicion of a parasitic condition, it was decided to collect the digestive tract for the determination of adult specimens. It was possible to observe the presence of Haemonchus contortus in the abomasum, of Trichostrongylus colubriformis in the small intestine, and of O. venulosum in the colon. The finding of O. venulosum in caprines adds to the reports of said NGI in other animal species of zootechnical interest in the NOA, and is, to our knowledge, the first description in caprines nationwide.

Abstract The objective was to evaluate the nematocidal effect of four hydroalcoholic extracts (HAE) of Brosimum alicastrum (HAE-Ba), Guazuma ulmifolia (HAE-Gu), Erythrina americana (HAE-Ea) and Leucaena leucocephala (HAE-Ll) against Haemonchus contortus. The tests of egg hatching inhibition (EHI) and larval (infective larvae) mortality were used. The treatments were HAEs at concentrations of 6.25-50 mg/mL for EHI and 25-100 mg/mL for larval mortality, ivermectin (5 mg/mL, positive control) and distilled water (negative control). Data were analyzed using an ANOVA and treatments with a concentration-dependent effect were subjected to a regression analysis to determine lethal concentrations (LC50 and LC90). In addition, a phytochemical analysis was performed on the extracts to identify the presence of the main secondary metabolites. The best ovicidal and larvicidal activity was observed in HAE-Gu with 96.78 % EHI at 6.25 mg/mL and 57.2 % larval mortality at 75 mg/mL. Followed by HAE-Ba showing 90 % EHI at 6.25 mg/mL and 58.0 % larval mortality at 75 mg/mL. The LC50 and LC90 of HAE-Gu on EHI were 2.7 and 4.4 mg/mL, respectively. While the LCs of this same extract on larvae were LC50= 64 and LC90= 125 mg/mL. The phytochemical analysis indicates that all extracts contain tannins, coumarins, flavonoids and terpenes. The fodder species G. ulmifolia and E. americana could be candidate plants for the control of H. contortus.

Resumen El objetivo del presente estudio fue evaluar el efecto nematicida de cuatro extractos hidroalcohólicos (EHA) de Brosimum alicastrum (EHA-Ba), Guazuma ulmifolia (EHA-Gu), Erythrina americana (EHA-Ea) y Leucaena leucocephala (EHA-Ll) contra Haemonchus contortus. Se usaron las pruebas de inhibición de la eclosión de huevos (IEH) y mortalidad larval (larvas infectantes). Los tratamientos fueron los EHA´s a concentraciones de 6.25-50 mg/ml para IEH y de 25-100 mg/ml para mortalidad larval, ivermectina (5 mg/ml, control positivo) y agua destilada (control negativo). Los datos se analizaron mediante un ANOVA y los tratamientos con efecto dependiente a la concentración se sometieron a un análisis de regresión para determinar las concentraciones letales (CL50 y CL90). Además, se realizó un análisis fitoquímico a los extractos para identificar la presencia de los principales metabolitos secundarios. La mejor actividad ovicida y larvicida fue observada en EHA-Gu con un 96.78 % de IEH a 6.25 mg/ml y 57.2 % de mortalidad larval a 75 mg/ml. Seguido de EHA-Ba mostrando 90 % IEH a 6.25 mg/ml y un 58.0 % de mortalidad larval a 75 mg/ml. Las CL50 y CL90 del EHA-Gu sobre la IEH fueron 2.7 y 4.4 mg/ml, respectivamente. Mientras que las CL´s de este mismo extracto sobre larvas fue de CL50=64 y CL90=125 mg/ml. El análisis fitoquímico indica que todos los extractos contienen taninos, cumarinas, flavonoides y terpenos. Las especies forrajeras G. ulmifolia y E. americana podrían ser plantas candidatas para el control de H. contortus.

ABSTRACT Soil management systems, including tillage and green manuring, are important for the control of nematodes and for the sustainable production. The objective was to select, through multivariate analysis, sustainable agroecosystems for yellow melon cultivated under irrigated conditions in the Brazilian semi-arid region. The long-term experiment is set up in Argissolo Vermelho- Amarelo (Ultisol) with six multifunctional agroecosystems, composed of the combination of three mixtures of cover crops (1 - 75% legumes + 25% grasses and oilseeds; 2 - 25% legumes + 75% grasses and oilseeds and 3 - spontaneous vegetation) and two types of soil management (no tillage-NT and tillage-T). The purpose was to evaluate the nutritional status of plants, soil fertility, nematode population in roots and soil, and the yield. Data were analyzed with multivariate techniques, allowing the grouping of the agroecosystems based on their similarities and complexity of functions. The incorporation of plant residues to the soil reduces nematode population, but their maintenance on the surface allows the improvement of fertility and yield, even under larger nematode populations. The agroecosystems that associate the nonincorporation of residues from cover crops with larger species diversity in composition constitute the most complex model, allowing different environmental functionalities. Thus, it is recommended not to incorporate the plant residues, planting the melon seedlings directly in the straw. However, considering that the results obtained with the non-incorporation of spontaneous vegetation were similar to those obtained with the incorporation of commercial cover crops, it is concluded that this practice is also viable and adapted to the semi-arid conditions.

RESUMO Sistemas de manejo de solos, incluindo revolvimento e adubação verde, são importantes para o controle de nematoides e para a produção sustentável. Objetivou-se selecionar, por meio da análise multivariada, agroecossistemas sustentáveis para cultivo irrigado de melão amarelo no Semiárido brasileiro. As avaliações ocorreram num experimento de longa duração, com seis agroecossistemas multifuncionais, compostos pela combinação de três misturas de plantas de cobertura (1 - 75% leguminosas + 25% gramíneas e oleaginosas; 2 - 25% leguminosas + 75% gramíneas e oleaginosas e 3 - vegetação espontânea) e dois tipos de manejo do solo (sem e com revolvimento). Avaliaram-se o estado nutricional das plantas, a fertilidade do solo, as populações de nematoides nas raízes e no solo e a produtividade da cultura. Os dados foram submetidos às técnicas de análises multivariadas, permitindo agrupar os agroecossistemas por semelhanças e complexidade das suas funções. A incorporação dos resíduos vegetais ao solo reduz a população de nematoides, mas sua manutenção na superfície permite melhorar a fertilidade e alcançar boas produtividades, mesmo sob maior população de nematoides. Os agroecossistemas que associam o não revolvimento dos resíduos vegetais das plantas de cobertura com maior diversidade de espécies na composição é o modelo considerado mais complexo, permitindo diferentes funcionalidades ambientais. Assim, recomenda-se não incorporar os resíduos vegetais, transplantando as mudas de meloeiro diretamente sobre a palhada. No entanto, considerando que os resultados obtidos com a não incorporação da vegetação espontânea foram semelhantes à incorporação das plantas de cobertura comerciais, conclui-se que esta prática também é viável e adaptada às condições semiáridas.

Abstract Root knot nematode M. incognita is one of the most dangerous and common species affecting Solanaceae family, including the naranjilla crop (S. quitoense). The objective of this work was to evaluate three species of Solanaceas as hosts (S. sessiliflorum, S. hirtum and S. quitoense) for an isolated of M. incognita in greenhouse. Plants of three species were planted in pots and each plant was inoculated with 2500 eggs and second stage juveniles (J2). Host suitability was assessed 80 days after inoculation. Initial inoculum was obtained from infested roots of S. quitoense plants collected in commercial naranjilla orchards. A completely randomized experimental design was used. The variables evaluated at 80 days after inoculation were: gall index (GI), nematode reproduction factor (RF), dry weight of the foliar area, plant height and stem diameter. All species were galled, but S. sessiliflorum and S. hirtum showed the least number of root knots with values of 33.73 and 34.73. Both were classified as resistant / hypersensitive with reproduction factors of 0.94 and 0.85 (RF> 1) respectively, while S. quitoense was susceptible with a value of 1.56. In terms of foliage yield (dry weight), plant height and stem diameter, S. sessiliflorum and S. hirtum showed a tolerance response in relation to S. quitoense.

Resumen El nematodo del nudo de la raíz Meloidogyne incognita es una de las especies más peligrosas y comunes que afectan a las solanáceas, entre ellas la naranjilla Solanum quitoense. El objetivo de este trabajo fue evaluar el potencial reproductivo de un aislamiento de M. incognita en tres especies de Solanaceas en invernadero: Solanum sessiliflorum, Solanum hirtum (reportada anteriormente como resistente) y S. quitoense (susceptible). Plantas de las tres especies fueron sembradas en maceta y a las cuatro semanas fueron inoculadas con 2500 huevos más juveniles en estado 2 (J2). El inóculo inicial se obtuvo de raíces infestadas de plantas de S. quitoense recolectadas en huertos comerciales de naranjilla. Se utilizó un diseño experimental completamente aleatorizado. Las variables evaluadas a los 80 días después de la inoculación fueron: índice de agallas (GI), factor de reproducción de nematodos (RF), peso seco del área foliar, altura de la planta y diámetro del tallo. Se encontró que las tres especies mostraron agallamiento, pero S. sessiliflorum y S. hirtum mostraron el menor número de nudos de raíz con valores de 33,73 y 34,73. Además, S. sessiliflorum y S. hirtum presentaron una categoría de resistente/hipersensitivo con factores de reproducción de 0,94 y 0,85 (RF > 1) respectivamente, mientras que S. quitoense fue susceptible con un valor de 1,56. En términos de rendimiento de follaje (peso seco), altura de la planta y diámetro del tallo se observó una respuesta de tolerancia en S. sessiliflorum y S. hirtum en relación a S. quitoense.

Resumen Introducción. M. exigua ocasiona pérdidas importantes en el cultivo del café (Coffea arabica). Una práctica común para su control, es el uso de productos químicos que, en ocasiones, no son suficientemente efectivos, son además costosos y tóxicos para el humano y el ambiente. Objetivo. Evaluar un nematicida biológico y un bioestimulante radical como una alternativa para reducir las poblaciones de M. exigua en el cultivo de café. Materiales y métodos. Se evaluaron cuatro tratamientos: un nematicida biológico, un bioestimulante radical, un testigo químico terbufos (TQ) y un testigo absoluto (TA) en plantas de café de tres años donde se realizaron los muestreos de nematodos en suelo y raíz. Se utilizó un diseño de bloques completos al azar con cuatro tratamientos y cuatro repeticiones. Para el conteo de M. exigua antes y después de la aplicación de los tratamientos, se recurrió al modelo lineal generalizado con distribución binomial negativa de los residuos (Proc GenMod de SAS 9.2). Resultados. No se encontraron diferencias significativas entre los tratamientos, es decir, ninguna de las alternativas evaluadas logró disminuir la población de nematodos, por el contrario, las poblaciones aumentaron después de tres meses de la aplicación de los productos. El uso del nematicida biológico aumentó las poblaciones en un 88%, el TQ en un 30%, el bioestimulante radical en un 137% y por último, el TA la aumentó en un 134%. Una razón de la baja eficacia podría estar relacionada con el número de aplicaciones de los productos. Conclusión. Por lo anterior, es necesario buscar nuevas y eficaces alternativas para el combate de nematodos.

Abstract Introduction. M. exigua causes important losses in the cultivation of coffee (Coffea arabica). A common practice for its control is the use of chemical products that sometimes are not effective, are also expensive and toxic for humans and the environment. Objetive. To evaluate a biological nematicide and a radical root biostimulant as an alternative to reduce populations of M. exigua in coffee cultivation. Materials and methods. Four treatments were evaluated: a biological nematicide, a root biostimulant, a chemical control terbufos (TQ) and an absolute control (TA) in three-year-old coffee plants in which nematodes were sampled in soil and root. A randomized complete block design with four treatments and four replications was used. For the count of M. exigua before and after treatments application, the generalized linear model with negative binomial distribution of the residuals (Proc GenMod of SAS 9.2) was used. Results. No significant differences were found between treatments, that is, none of the evaluated alternatives managed to reduce the population of nematodes, on the contrary, the populations increased after three months of application. The use of the biological nematicide increased population by 88%, TQ by 30%, root bioestimulant by 137%, and finally, TA by 134%. Conclusion. One reason for the low efficacy could be related to the number of applications of the products. Therefore, it is necessary to look for new and effective alternatives to combat nematodes.

ABSTRACT In the Brazilian Cerrado, phytonematodes, phytonematodes are a challenge for agriculture, and the association of forms of control is the best strategy to be used in coexistence with this pathogen. Faced with this problem, this study aimed to evaluate the efficiency of cover crops and biocontrol agents in the management of nematodes in soybean. For each nematode species under study (Meloidogyne incognita and Pratylenchus brachyurus), two experiments were carried out under greenhouse conditions in a completely randomized design arranged in a 6 × 2 factorial scheme with eight replications. Six cover crops (millet ADRG 9050, millet ADR 300, Urochloa ruziziensis, Crotalaria ochroleuca, C. spectabilis, and corn hybrid DKB 290) and two treatments (treated or not with Bacillus subtilis and B. methylotrophicus - 1×106 CFU per seed) were evaluated. The cover crops were sown in soil infested with nematodes and then soybeans were sown under the straw, and cultivated for 45 and 60 days, for M. incognita and P. brachyurus, respectively. Fresh root mass, total nematode population, and the number of nematodes per gram of root were evaluated. The association of microorganisms with C. spectabilis, U. ruziziensis, and millet ADR 300 conferred an additional effect in reducing the population of P. brachyurus. For M. incognita, the association was successful only for combining C. spectabilis with B. methylotrophicus. DKB 290 corn, when treated with B. methylotrophicus, had the nematode population per gram of soybean root reduced by 90% compared to plants that did not receive biological treatment.

RESUMO No Cerrado brasileiro, os fitonematoides são um desafio para agricultura, sendo a associação de formas de controle a melhor estratégia a ser utilizada na convivência com esse patógeno. Diante dessa problemática, o objetivo desse trabalho foi avaliar a eficiência de plantas de cobertura e agentes de biocontrole no manejo de nematoides na cultura da soja. Foram desenvolvidos dois ensaios em condições de casa de vegetação para os nematoides Meloidogyne incognita e Pratylenchus brachyurus, em delineamento inteiramente casualizado, em esquema fatorial 6 (plantas de cobertura: milheto ADRG 9050, milheto ADR 300, Urochloa ruziziensis, Crotalaria ochroleuca, C. spectabilis e milho DKB 290) × 2 (tratados ou não com Bacillus subtilis e B. methylotrophicus - 1×106 UFC por semente), com oito repetições. As plantas de cobertura foram semeadas em solo infestado com nematoides e na sequência semeada soja sob a palha, e cultivada por 45 e 60 dias, para M. incognita e P. brachyurus, respectivamente. Foram avaliadas a massa fresca de raízes e o número de nematoides totais e por grama de raiz. A associação dos microrganismos com C. spectabilis, U. ruziziensis e milheto ADR 300 conferiram efeito adicional na redução da população de P. brachyurus. Para a espécie M. incognita a associação foi bem sucedida apenas para a combinação da C. spectabilis com B. methylotrophicus. O milho DKB 290, quando tratado com B. methylotrophicus, teve a população do nematoide por grama de raiz da soja reduzida em 90 % em comparação às plantas que não receberam o tratamento biológico.

ABSTRACT Toxocariasis is a prevalent zoonosis with a significant socioeconomic impact, particularly in poor communities around the world. It is caused by larval forms of nematode species, parasites of the Toxocara genus. The spectrum of clinical manifestations in toxocariasis varies widely from asymptomatic cases to systemic infections. In the case of ocular toxocariasis, impaired visual acuity is the most common manifestation when symptoms are present. Ocular presentations include chronic endophthalmitis, posterior pole granuloma, or a peripheral granuloma. We present the case of a 12-year-old patient with ocular toxocariasis in the form of a posterior pole granuloma with vitreous tractional bands, which is accompanied by a hyperpigmented lesion in the macular area in the healing phase. The purpose of our publication is to highlight the multiple ocular complications that can occur in patients with ocular toxocariasis, which ultimately lead to irreversible visual loss.

RESUMEN La toxocariasis es una zoonosis prevalente con un importante impacto socioeconómico, particularmente en las comunidades pobres de todo el mundo. Es causada por formas larvarias de especies de nematodos, parásitos del género Toxocara. El espectro de manifestaciones clínicas en la toxocariasis varía ampliamente, desde casos asintomáticos a infecciones generalizadas. En el caso de la toxocariasis ocular, el deterioro de la agudeza visual es la manifestación más común cuando los síntomas están presentes. Las presentaciones oculares incluyen endoftalmitis crónica, granuloma de polo posterior o granuloma periférico. Presentamos el caso de una paciente de 12 años, con toxocariasis ocular en forma de granuloma de polo posterior con bandas traccionales a vítreo, acompañada de una lesión hiperpigmentada en el área macular en fase cicatrizal. El propósito de esta publicación es describir las múltiples complicaciones oculares que pueden concomitar en el paciente con toxocariasis ocular, que finalmente conllevan a una pérdida visual irreversible.