BACKGROUND The nematode Angiostrongylus cantonensis, which is endemic to Southeast Asia and adjacent Pacific Islands, has already been recorded in more than 30 countries, including Brazil and other South American nations. It is one of the principal etiological agents of the zoonosis Eosinophilic Meningitis (EoM), which has a number of different species of terrestrial gastropods that act as its intermediate hosts. OBJECTIVE The present study investigated the occurrence of the larvae of this nematode in specimens of terrestrial molluscs collected in half of the municipalities of the Brazilian State of Rio de Janeiro. METHODS The study is based on the surveillance of this nematode in the Brazilian State of Rio de Janeiro, where terrestrial snails and slugs were collected in more than half of the state’s municipalities (46 in all), and examined for parasitological infections. The nematode larvae retrieved from these specimens were identified based on their morphology and cytochrome oxidase I (COI) mitochondrial DNA sequences. FINDINGS Angiostrongylid larvae were found in 230 (8.8%) of the 2,600 terrestrial molluscs examined, collected from 26 municipalities. Overall, 14 terrestrial gastropod species were identified, including both native and exotic taxa, and six were found to be infected naturally by A. cantonensis. The natural infection rates by Angiostrongylus in the different terrestrial molluscs species were 12.5% in Angustipes erinaceus, 9.7% in Achatina fulica, 6.8% in Bradybaena similaris, 6.3% in Sarasinula linguaeformis, 3.9% in Leptinaria unilamellata, and 4.6% in Subulina octona. A. fulica was the most frequent and extensively distributed species, with infected snails being found in 22 municipalities. MAIN CONCLUSIONS The data from this first comprehensive survey of A. cantonensis in Rio de Janeiro highlights the potential epidemiological risk of human infection in this state. Mapping the spread of infected molluscs will also provide essential information for the evaluation of the risk of human infection, and should help local health authorities to provide a faster and more accurate diagnosis whenever neuroangiostrongyliasis is suspected.

Selenium-containing compounds exhibit diverse biological activities, such as antioxidative, anti-inflammatory, and cancer preventive effects. Using Caenorhabditis elegans as a model organism, we assessed the toxicity, neuroprotective, antioxidant properties, and impact on longevity of 11 selenoacetylenes. Their toxicity and bioactivities varied based on molecular structure. Selenoacetylenes with butyl substituents were toxic to Galleria mellonella larvae. The presence of but-3-in-2-ol radical increased antiprotozoal activity against Tetrahymena pyriformis. Compared to the positive control (Nimitz® EC), selenoacetylenes were less toxic to nematode worms and eggs. Selenoacetylenes significantly reduced amyloid beta (Aβ) paralysis in C. elegans CL4176 worms, increased longevity by 18 to 22%, along with improving survival after oxidative or thermal stress. Galantamine, showed inferior results. These findings enhance our understanding of selenoacetylenes on neuroprotection, antioxidant activity, and longevity in C. elegans. Future mammalian studies will further elucidate mechanisms and explore the potential therapeutic use of selenoacetylenes in treating Alzheimer’s disease and longevity. Seleniumcontaining Selenium containing activities antioxidative antiinflammatory, antiinflammatory anti inflammatory, inflammatory anti-inflammatory effects organism neuroprotective properties 1 structure larvae but3in2ol butinol but 3 2 ol pyriformis Nimitz® Nimitz (Nimitz EC, EC , EC) eggs Aβ (Aβ C CL CL417 22 22% stress Galantamine results neuroprotection Alzheimers Alzheimer s CL41 CL4

ABSTRACT The present study investigated the impact of different concentrations of Trichoderma harzianum on the growth variables of tomato plants infected with both root-knot nematodes (Meloidogyne incognita) and the bacterial wilt pathogen (Ralstonia solanacearum). Application of T. harzianum significantly improved growth variables such as shoot and root lengths and shoot weight (p 0.001), with the highest growth observed at the concentration of 1×104 spores/mL. Lower concentrations (8×103 and 2×103 spores/mL) also enhanced growth, but to a lesser extent. Notably, root weight decreased, indicating reduced gall formation, a positive outcome against nematode infestation. The study revealed that T. harzianum significantly reduced the number of galls, eggmasses, and nematode reproduction factors (p 0.001). The highest concentration (1×104 spores/mL) was most effective, followed by 8×103 spores/mL, demonstrating a dose-responsive reduction in these parameters. Regression analysis showed positive correlations between decreased gall numbers and increased shoot and root lengths and weights, as well as between reduced eggmasses and improved growth variables. Regarding disease severity, increasing concentrations of T. harzianum notably decreased the severity of both root-knot nematodes and bacterial wilt compared to the control. The control treatment exhibited a 72.5% severity, whereas treatments with T. harzianum reduced severity to 51–55.5%, and the highest concentration reduced it to 2.5%. This trend was consistent for bacterial wilt severity. The results indicate that T. harzianum effectively colonizes tomato roots, inhibiting pathogen entry and reducing disease severity more effectively at higher concentrations. rootknot knot Meloidogyne incognita Ralstonia solanacearum. solanacearum . solanacearum) T p 0.001, 0001 0.001 , 0 001 0.001) 1104 1 104 1×10 sporesmL spores mL spores/mL 8103 8 103 (8×10 2103 2 2×10 extent Notably formation infestation galls 0.001. (1×10 effective 8×10 doseresponsive dose responsive parameters weights 725 72 5 72.5 51555 51 55 51–55.5% 25 2.5% roots 000 0.00 00 110 10 1×1 810 (8×1 210 2×1 (1×1 8×1 7 72. 5155 51–55.5 2.5 0.0 11 1× 81 (8× 21 2× (1× 8× 515 51–55. 2. 0. (8 (1 51–55 ( 51–5 51–

Resumen Introducción. La producción de banano es una de las actividades económicas más significativas para el país. Sin embargo, enfrenta serios desafíos debido a la presencia de diversos patógenos, entre los más significativos se encuentran los nematodos fitoparásitos que afectan el rendimiento y la calidad del cultivo. El uso de hongos nematófagos (HN) para el control biológico de nematodos es una alternativa para reducir la aplicación de productos químicos en cultivos agrícolas. En Costa Rica existe gran variedad de hongos debido a la diversidad de los suelos, por lo que el aislamiento y la correcta identificación de estos hongos es crucial para determinar su potencial antagonista. Objetivo. Aislar e identificar potenciales hongos nematófagos (PHN) presentes en muestras de suelo de plantaciones de banano de la región Huetar Atlántica. Materiales y métodos. Se analizaron seis muestras de suelo provenientes de cinco cantones de la región Huetar Atlántica de Costa Rica mediante el método de espolvoreado en placas con agar-agua en búsqueda de PHN. Para la selección y purificación de los PHN se utilizaron placas Petri con papa dextrosa agar (PDA), identificando las estructuras morfológicas para el diagnóstico a nivel de género. Los hongos identificados morfológicamente se replicaron y se conservaron en viales con PDA y en aceite mineral a 4°C. Se extrajo ADN de los PHN y mediante amplificación por PCR (Reacción de Cadena de la Polimerasa) y secuenciación de diferentes regiones del genoma (ITS, tef 1-alfa, rpb2 y β-tubulina), se identificaron molecularmente. Resultados. Se aislaron e identificaron doce hongos, entre ellos Trichoderma asperellum, Penicillium steckii, Purpureocillium lilacinum, Fusarium oxysporum, Fusarium sp., Fusarium pseudocircinatum, y Talaromyces sp. Conclusión. El descubrimiento e identificación correcta de PHN subraya la importancia de investigar su aplicación en programas de manejo integrado de plagas, así como la necesidad de evaluar su eficacia y seguridad en diferentes condiciones agroecológicas para maximizar su impacto positivo en la agricultura.

Abstract Introduction. Banana production is one of the most significant economic activities for the country. However, it faces serious challenges due to the presence of various pathogens, among the most significant are plant-parasitic nematodes that affect crop yield and quality. The use of nematophagous fungi (NF) for biological control of nematodes is an alternative to reduce the application of synthetic chemicals in agricultural crops. In Costa Rica there is a great variety of fungi due to the diversity of soils. Therefore, the isolation and correct identification of these fungi is crucial to determine their antagonistic potential. Objective. To isolate and identify the potential nematophagous fungi (PNF) present in soil samples from banana plantations at the Huetar Atlantic region. Materials and methods. Six soil samples from the Huetar Atlantic region of Costa Rica were analyzed by the agar-water sprinkling plates method in search of PNF. For PNF selection and purification, Petri dishes with potato dextrose agar (PDA) were used, identifying morphological structures for diagnosis at genus level. Morphologically identified fungi were replicated and preserved in vials with PDA and in mineral oil at 4°C. DNA was extracted from the isolated PNF and through PCR amplification (Polymerase Chain Reaction) and sequencing of different regions of the genome (ITS, tef 1-alpha, rpb2 and β-tubulin), they were molecularly identified. Results. Twelve fungi were isolated and identified, including Trichoderma asperellum, Penicillium steckii, Purpureocillium lilacinum, Fusarium oxysporum, Fusarium sp., Fusarium pseudocircinatum, and Talaromyces sp. Conclusion. The correct discovery and identification of PNF underscores the importance of investigating its application in integrated pest management programs, as well as the need to evaluate its efficacy and safety under different agroecological conditions to maximize its positive impact on agriculture.

Resumen Introducción. El ñame es un cultivo importante en varias regiones de Costa Rica. A pesar de ello, las pérdidas poscosecha son altas y no están cuantificadas. Objetivo. El estudio se realizó para determinar las causas del deterioro de calidad y pérdidas poscosecha en zonas productoras de ñame ubicadas en los cantones localizados en las provincias de Alajuela, Heredia y Limón. Materiales y métodos. Se determinó la calidad de los tubérculos en dos momentos del proceso poscosecha: 1) durante la etapa de curado (15 a 30 días a 25-30°C y 85% HR) y 2) al finalizar la simulación de envío a mercado (16°C y 85% HR durante 28 días). En ambas etapas se midieron las siguientes variables de calidad: peso; longitud; número de golpes por tubérculo y número de estrías abiertas o cerradas por tubérculo; incidencia de moho superficial y de corte, pudrición externa e incidencia de pudrición por nematodos. Resultados. Al finalizar el curado, la presencia de estrías abiertas fue importante en algunas zonas (30% incidencia en San Carlos), la presencia de mohos superficiales y en corte de cosecha (hasta 21% incidencia de ambos factores en Upala), los daños por nematodos (35 % incidencia en Pococí), aunado a variaciones de tamaño (largo, ancho y peso) fueron factores importantes de pérdidas. Concluida la simulación de transporte, la presencia de daños por nematodos (hasta 35% incidencia), presencia de moho superficial (15% incidencia) y en el corte de cosecha (hasta 49% incidencia), y pudriciones externas (hasta 5% incidencia) fueron causas relevantes de pérdidas. Conclusión. Los resultados apuntan hacia la necesidad de hacer en las zonas de estudio, una revisión integral de las prácticas de cultivo y poscosecha con el fin de reducir los factores causantes de los defectos de calidad identificados.

abstract Introduction. The yam is an important crop in several regions of Costa Rica. However, postharvest losses are high and not quantified. Objective. This study was conducted to determine the causes of quality deterioration and postharvest losses in yam-producing areas located in the provinces of Alajuela, Heredia, and Limón. Materials and methods. The quality of the tubers was determined at two postharvest stages: 1) during the curing stage (15 to 30 days at 25-30°C and 85% RH) and 2) at the end of the market shipping simulation (16°C and 85% RH for 28 days). The following quality variables were measured in both stages: weight, length, number of impacts per tuber, number of open or closed striae per tuber, incidence of surface and cut mold, external rot, and incidence of nematode rot. Results. At the end of curing, the presence of open striae was significant in some areas (30% incidence in San Carlos), the presence of surface and cutting mold at harvest (up to 21% incidence of both factors in Upala), nematode damage (35% incidence in Pococí), along with size variations (length, width, and weight) were important factors contributing to losses. At the end of the transportation simulation, the presence of nematode damage (up to 35% incidence), surface mold (15% incidence), cutting mold (up to 49% incidence), and external rot (up to 5% incidence) were significant causes of losses. Conclusion. The results suggest that in the region of the study, a comprehensive review of cultivation and postharvest practices is necessary in order to reduce the factors causing the identified quality defects.

Resumen Se analizaron muestras de suelo y raíces del cultivo del pepino. Se extrajeron e identificaron los nematodos fitopatógenos presentes. Juveniles de Meloidogyne incognita fueron los más abundantes en suelo, otros como Aphelenchoides sp., Pratylenchus sp., Tylenchorynchus sp., y Aphelenchus sp. se encontraron con menor presencia. De las raíces se obtuvieron hembras y huevos de M. incognita. Con el fin de encontrar alternativas a los productos químicos fumigantes utilizados en exceso, se evaluaron las rizobacterias Bacillus vallismortis, Bacillus velezensis y Pseudomonas fluorescens, que fueron fermentadas y filtradas para ponerse en contacto con estos nematodos bajo condiciones in vitro, observando su efecto cada 24 h. Los tratamientos se analizaron en concentraciones de 100 % y 50 %. El filtrado de P. fluorescens presentó la mejor actividad nematicida, ocasionando una mortalidad de 95 % en la concentración más alta y de 93 % en la concentración de 50 % a las 24 h, seguido por los tratamientos de B. vallismortis y B. velezensis con 83 y 77 % de respectivamente, en las concentraciones más altas. Los tres tratamientos ocasionaron un 100 % de mortalidad de los nematodos a 48 h de exposición, indicando, que contienen acción nematicida y pueden ser una alternativa viable para el control de estos fitopatógenos.

Abstract Soil and root samples of the cucumber crop were analyzed. Plant pathogenic nematodes present were extracted and identified. The juveniles of the root-knot nematode Meloidogyne incognita were the most abundant in soil, other such as Aphelenchoides sp., Pratylenchus sp., Tylenchorynchus sp., and Aphelenchus sp. were found in less presence. Females and eggs of M. incognita were obtained from the roots. Finding alternatives to chemicals fumigants, the rhizobacterias Bacillus vallismortis, Bacillus velezensis and Pseudomonas fluorescens were fermented and filtered to be evaluated on these filiform nematodes under laboratory conditions, observing their effect every 24 h. The treatments were evaluated at concentrations of 100 % and 50 %. The P. fluorescens filtrate was the treatment with the best nematicidal activity, causing a mortality of 95 % at the highest concentration and 93 % at the 50 % at 24 h, followed by the treatments of B. vallismortis and B. velezensis with 83 and 77 % respectively at concentrations of 100 % product. The three treatments showed 100 % mortality of the nematodes after 48 hours of exposure, indicating that these rhizobacteria contain metabolites with nematicidal action that could be a healthy alternative for the control of these phytopathogens.

Resumen Haemonchus contortus es un nematodo hematófago con alta tasa de reproducción, considerado como el principal problema en pequeños rumiantes en pastoreo. Por tanto, se buscan alternativas de tratamiento con base en el uso de los extractos vegetales. El objetivo de este estudio fue evaluar la actividad ovicida de Artemisia cina contra el parásito Haemonchus contortus y caracterizar químicamente el extracto con mayor actividad biológica a través de cromatografía de gases acoplado a espectrometría de masas (CG-MS). La obtención de los extractos a evaluar, se realizó con la técnica de maceración utilizando metanol, acetato de etilo y n-hexano. Los extractos se llevaron a sequedad total y se desafiaron frente a los huevos de H. contortus utilizando la técnica de inhibición de la eclosión de huevos descrita por la Asociación Mundial para el Avance de la Parasitología Veterinaria (WAAVP, por sus siglas en inglés). El extracto metanólico (EM) mostró el 100 % de actividad ovicida a una concentración de 4.25 mg/ml, siendo el más activo a una baja concentración, por tanto se caracterizó con CG-MS. EL EM posee principalmente ácidos grasos y terpenos; de ellos, el ácido hexadecanoico y el 2-[4-metil-6-(2,6,6-trimetilciclohex-1-enil) exa-1,3,5-trienil][ciclohex]-1-en-carboxialdehido. Los compuestos caracterizados han mostrado actividad antihelmíntica previamente reportada, por lo que la actividad ovicida puede estar asociada a estos. En conclusión, el extracto metanólico de A. cina tuvo una mayor actividad ovicida a bajas concentraciones, esto se debe probablemente a la presencia de ácidos grasos y terpenos.

Abstract Haemonchus contortus is a hematophagous nematode with a high reproduction rate, considered to be the main problem in grazing small ruminants. Therefore, treatment alternatives based on the use of plant extracts are sought. This study aimed to evaluate the ovicidal activity of Artemisia cina against the parasite Haemonchus contortus and to chemically characterize the extract with the highest biological activity through gas chromatography coupled with mass spectrometry (GC-MS). The extracts to be evaluated were obtained through the maceration technique using methanol, ethyl acetate, and n-hexane. The extracts were taken to total dryness and challenged against H. contortus eggs using the egg-hatching inhibition technique described by the World Association for the Advancement of Veterinary Parasitology (WAAVP). The methanolic extract (ME) showed 100 % ovicidal activity at a concentration of 4.25 mg/ml, being the most active at a low concentration; therefore, it was characterized by GC-MS. ME mainly contains fatty acids and terpenes; among them are hexadecanoic acid and 2-[4-methyl-6-(2,6,6-trimethylcyclohex-1-enyl)hexa-1,3,5-trienyl][cyclohex]-1-en-carboxyaldehyde. The characterized compounds have shown previously reported anthelmintic activity so that ovicidal activity may be associated with them. In conclusion, the methanolic extract of A. cina had a higher ovicidal activity at low concentrations; this is probably due to the presence of fatty acids and terpenes.

Resumen Se evaluó el efecto nematicida del extracto de semillas de Canavalia ensiformis combinado con nanopartículas de dióxido de silicio, en juveniles de segundo estadio (J2) de Meloidogyne incognita, nematodo fitopatógeno que afecta el cultivo de tomate. En el primer experimento, se probaron concentraciones del extracto al 2, 4, 6, 8 y 10%, observando que la concentración más efectiva fue del 10%, con una mortalidad del 90% a las 24 horas. En el segundo experimento, se combinaron concentraciones del extracto al 1.5, 2.0, 2.5 y 3.0% con nanopartículas de dióxido de silicio al 0.06, 0.08, 0.10, 0.12 y 0.14%, donde la más eficaz fue la de 1.5% de extracto con 0.14% de nanopartículas, que mostró una mortalidad del 94% a las 72 horas. Estos resultados sugieren que la combinación de extracto de C. ensiformis con las NP’s puede ser una estrategia para el manejo de M. incognita en cultivos de tomate.

Abstract The nematicidal effect of Canavalia ensiformis seed extract combined with silicon dioxide nanoparticles was evaluated on second instar juveniles of Meloidogyne incognita, a phytopathogenic nematode that affects tomato crops. In the first experiment, concentrations of the extract were tested at 2, 4, 6, 6, 8 and 10%, observing that the most effective concentration was 10%, with 90% mortality at 24 hours. In the second experiment, concentrations of the extract at 1.5, 2.0, 2.5 and 3.0% were combined with silicon dioxide nanoparticles at 0.06, 0.08, 0.10, 0.12 and 0.14%, where the most effective was 1.5% extract with 0.14% nanoparticles, which showed a mortality of 94% at 72 hours. These results suggest that the combination of C. ensiformis extract with NP's can be a strategy for the management of M. incognita in tomato crops.

ABSTRACT: The invasive chinese slug Meghimatiumpictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) is originally from Asia, and it has been introduced in Latin American countries like Argentina and Brazil, where it is considered a critical horticultural pest. This species also became an intermediate host for the nematode AngiostrongyluscostaricensisMorera&Cespedes, 1971(Strongylida: Metastrongylidae), which can cause abdominal angiostrongyliasis in humans when ingested molluscs or their mucus containing larvae released on fruit and vegetables. This research aimed to investigate the biological parameters of the life cycle of M. pictum and evaluate its food preference to understand the species’ behavior and provide information on the choice of safer pest management and control methods. We observed that 68 and 75% of the grouped and isolated slugs, respectively, survived 26 weeks (180 days) under laboratory conditions. In addition, the individuals kept isolated had higher body mass (2.8 ± 0.6 g), length (3.3 ± 0.8 cm), and width (0.37 ± 0.3 cm) than grouped specimens. We also found that M. pictum has indeterminate growth and an annual reproductive cycle. Concerning food preference, slugs better accepted lettuce at different developmental stages (neonate, juvenile, and adult). Our study presents the first description of the M. pictum life cycle. We concluded that M. pictum has undefined biological parameters, which hampers its laboratory rearing. However, we also demonstrate its potential as a pest for different horticultural crops, which will require the development of management strategies. ABSTRACT Stoliczka, Stoliczka (Stoliczka 1873 Stylommathophora (Stylommathophora Philomycidae Asia Brazil AngiostrongyluscostaricensisMoreraCespedes AngiostrongyluscostaricensisMorera Cespedes AngiostrongyluscostaricensisMorera&Cespedes 1971Strongylida Strongylida 1971 1971(Strongylida Metastrongylidae, Metastrongylidae , Metastrongylidae) vegetables M methods 6 75 respectively 2 180 (18 days conditions addition 2.8 28 8 (2. 06 0 0. g, g g) 3.3 33 3 (3. 08 cm, cm 0.37 037 37 (0.3 03 specimens neonate, neonate (neonate juvenile adult. adult . adult) rearing However crops strategies 187 197 7 18 (1 2. (2 3. (3 (0. 19 1 ( (0

RESUMO: A lesma invasora Meghimatium pictum (Stoliczka, 1873) (Stylommathophora: Philomycidae) é originária da Ásia e foi introduzida em países latino-americanos como Argentina e Brasil, onde é considerada uma praga hortícola severa. Esta espécie também se tornou um hospedeiro intermediário do nematoide Angiostrongylus costaricensis Morera & Céspedes, 1971 (Strongylida: Metastrongylidae), que pode causar a infecção angiostrongilíase abdominal em humanos quando ingerido o molusco ou frutas e vegetais contendo o seu muco contaminado com larvas. Esta pesquisa teve como objetivo investigar os parâmetros biológicos do ciclo de vida de M. pictum e avaliar sua preferência alimentar para entender o comportamento da espécie e fornecer informações sobre a escolha futura de métodos mais seguros de manejo e controle desta praga. Observamos que 68 e 75% das lesmas agrupadas e isoladas, respectivamente, sobreviveram 26 semanas (180 dias) em condições de laboratório. Além disso, os indivíduos mantidos isolados apresentaram maior massa corporal (2,8 ± 0,6 g), comprimento (3,3 ± 0,8 cm) e largura (0,37 ± 0,3 cm) do que os espécimes agrupados. Também descobrimos que M. pictum tem crescimento indeterminado e ciclo reprodutivo anual. Com relação à preferência alimentar, a alface foi bem aceita pelas lesmas em diferentes estágios de desenvolvimento (recém-nascido, juvenil e adulto). Nosso estudo apresenta a primeira descrição do ciclo de vida de M. pictum. Concluímos que M. pictum possui parâmetros biológicos indefinidos, com ciclo de vida longo o que dificulta sua criação em laboratório. No entanto, também demonstramos seu potencial como praga para diferentes culturas hortícolas, o que exigirá o desenvolvimento de estratégias de manejo. RESUMO Stoliczka, Stoliczka (Stoliczka 1873 Stylommathophora (Stylommathophora Philomycidae latinoamericanos latino americanos Brasil severa Céspedes 197 Strongylida (Strongylida Metastrongylidae, Metastrongylidae , Metastrongylidae) larvas M 6 75 isoladas respectivamente 2 180 (18 dias laboratório disso 2,8 28 8 (2, 06 0 0, g, g g) 3,3 33 3 (3, 08 cm 0,37 037 37 (0,3 03 agrupados anual recémnascido, recémnascido recém nascido, nascido (recém-nascido adulto. adulto . adulto) indefinidos entanto hortícolas 187 19 7 18 (1 2, (2 3, (3 (0, 1 ( (0

Resumen El haba es uno de los cultivos más importantes en el altiplano mexicano, debido a su adaptación a las condiciones edafoclimáticas y a su alto valor nutrimental en la dieta de los habitantes de esta región. Sin embargo, los rendimientos obtenidos son bajos comparado con el promedio mundial. Los nematodos fitoparásitos son una de las principales limitantes para la producción de haba en otras partes del mundo; no obstante, en México se desconoce su presencia en este cultivo. En este trabajo se identificaron y cuantificaron los nematodos fitoparásitos asociados a cultivos de haba en 10 predios de los municipios de Tepeyahualco y Cuyoaco, Puebla y en plantas germinadas en suelo estéril a partir de semillas provenientes de diferentes zonas en el año 2022. Se encontraron seis géneros de nematodos fitoparásitos: Criconemoides, Ditylenchus, Helicotylenchus, Hoplolaimus, Pratylenchus y Zygotylenchus. Los géneros más abundantes fueron Ditylenchus y Pratylenchus con una densidad de población de 11 y 7 ejemplares por 100 cm3 de suelo y 159 y 60 ejemplares por 100 g de tejido vegetal respectivamente y se encontraron en todos los sitios de muestreo. La densidad de población de Ditylenchus sobrepasa el umbral económico del cultivo, además, ejemplares de este género se encontraron en las plantas germinadas en suelo estéril. Los resultados demuestran que Ditylenchus está distribuido en toda la zona muestreada, y puede causar afectaciones en el rendimiento. Es necesario realizar más estudios para determinar la identidad de las especies de nematodos y su distribución en otras zonas de producción.

Abstract The broad bean is one of the most important crops in the Central Mexican Plateau due to its adaptation to edaphoclimatic conditions and its high nutritional value in the diet of the inhabitants of this region. Nonetheless, the yields obtained are low compared to the world average. Phytoparasitic nematodes are one of the main constraints to broad bean production in other parts of the world; however, its presence in this crop is unknown in Mexico. In this work, phytoparasitic nematodes associated with broad bean crops were identified and quantified in 10 farms in the municipalities of Tepeyahualco and Cuyoaco, Puebla, and in plants germinated in sterile soil from seeds from different areas in 2022. The following six genera of phytoparasitic nematodes were found: Criconemoides, Ditylenchus, Helicotylenchus, Hoplolaimus, Pratylenchus and Zygotylenchus. The most abundant genera were Ditylenchus and Pratylenchus, with a population density of 11 and 7 specimens per 100 cm3 of soil and 159 and 60 specimens per 100 g of plant tissue, respectively, and they were found in all sampling sites. The population density of Ditylenchus exceeds the economic threshold of the crop; in addition, specimens of this genus were found in plants germinated in sterile soil. The results show that Ditylenchus is distributed throughout the sampled area and can affect yield. Further studies are needed to determine the identity of nematode species and their distribution in other production areas.

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.

Resumen Introducción y objetivos: El falso nematodo de la agalla (Nacobbus spp.) comprende especies polífagas, siendo el pimiento (Capsicum annuum) uno de los cultivos más afectados. Debido a la falta de genotipos resistentes del pimiento, comparamos las respuestas de diferentes cultivares comerciales para identificar posibles mecanismos de defensa contra N. celatus. M&M: Nematodos provenientes de Río Cuarto (provincia de Córdoba) y Lisandro Olmos (provincia de Buenos Aires) se inocularon en cultivares de pimiento: California Wonder, Fyuco INTA, Yatasto y Fenomeno RZ. Las plantas se desarrollaron en invernadero y las agallas se analizaron mediante técnicas histopatológicas. Resultados: Las raíces de los cultivares analizados mostraron las alteraciones morfo-anatómicas típicas inducidas por N. celatus: formación de agallas, reacciones de hiperplasia, desarrollo de sincitios en el cilindro central y desorganización de los tejidos vasculares. Las células sincitiales en contacto con hembras de Lisandro Olmos mostraron una reacción de defensa por parte de Fyuco INTA, mientras que los sincitios en Fenomeno RZ denotaron baja actividad metabólica en nematodos de ambas procedencias. Conclusiones: Las diferencias observadas entre las poblaciones y/o hospedadores demuestran la importancia de considerar nematodos de diferentes orígenes geográficos al analizar material vegetal para determinar su tolerancia y/o resistencia a N. celatus. Estudios de esta naturaleza son necesarios ya que facilitan una comprensión más profunda de la interacción parásito-planta.

Summary Background and aims: The false-root knot nematode (Nacobbus spp.) comprises polyphagous species, with pepper (Capsicum annuum) being one of the most affected crops. Due to the lack of resistant pepper genotypes, we compared the responses of different commercial cultivars to identify possible plant defence mechanisms against N. celatus. M&M: Nematodes from Río Cuarto (Córdoba Province) and Lisandro Olmos (Buenos Aires Province) were inoculated on pepper cultivars: California Wonder (control), Fyuco INTA, Yatasto, and Fenomeno RZ. Plants were grown under a greenhouse and galls were analysed by histopathological techniques. Results: The roots of the commercial cultivars showed the typical morpho-anatomical alterations induced by N. celatus: gall formation, hyperplasia reactions, development of syncytia in the central cylinder and disorganisation of vascular tissues. Syncytial cells in contact with females of nematodes from Lisandro Olmos showed a defence reaction by Fyuco INTA, whereas feeding sites in Fenomeno RZ did not denote high metabolic activity in nematodes of both origins. Conclusions: The different responses observed between populations and/or hosts demonstrate the importance of considering nematodes from different geographical origins when testing plant material for tolerance and/or resistance to N. celatus. Studies of this nature are necessary since they facilitate a more in-depth understanding of the parasite-plant interaction.

ABSTRACT Meloidogyne enterolobii is currently the most damaging nematode of the genus Meloidogyne due to its aggressiveness and ability to overcome existing sources of resistance; therefore, the search for genotypes with resistance in crops of high economic importance such as chili pepper (Capsicum annuum L. var. annuum) is one of the greatest challenges facing agricultural researchers. The aim of this study was to determine the level of resistance in C. annuum landraces from Mexico to different population densities of M. enterolobii. Five C. annuum landraces (UTC24, UTC25, UTC66, UTC67, and UTC90) and the commercial cv. Revelation were used. The experiment was conducted twice under greenhouse conditions with a randomized block design with four replicates per genotype and cultivar. Inoculation was performed on 21-d-old seedlings with inoculum doses of 0, 4500, 9000, and 13500 eggs plant-1. The gall index, reproduction factor, and reproduction index were evaluated at 42 and 63 d after inoculation. Genotypes UTC66, UTC67, and UTC90 showed a higher level of resistance with a damage percentage lower than 50% compared to ‘Revelation’ (susceptible). Genotype UTC90 showed the lowest reproduction factor and index, so it was considered a highly resistant genotype to an inoculum dose of 4500 M. enterolobii eggs with a damage percentage of less than 10%, while, at a dose of 13 500 eggs, its resistance level was intermediate. The results of this study contribute to the search for sources of resistance to M. enterolobii in chili pepper landraces.

RESUMEN Se determinó la presencia de parásitos gastrointestinales (PGI) en ovinos de carne provenientes de predios de la precordillera de la comuna de San Clemente Chile mediante un muestreo por conveniencia (n=100) entre agosto y noviembre de 2022. Se colectaron muestras fecales del recto y se procesaron mediante la técnica de sedimentación de Dennis modificada para la determinación de huevos de F. hepatica y la técnica de flotación de Sheather para determinación de huevos de nemátodos y coccidias. Además, se realizó la técnica cuantitativa de McMaster modificado en las muestras. Se encontró mayor prevalencia de parásitos de la familia Trichostrongylidae (68%), seguido de F. hepatica (47%), Nematodirus sp (25%) y Eimeria sp (43%). Además, se evaluaron las variables epidemiológicas edad, sexo y estado sanitario. El grupo etario fue significativo (p=0.003) para la variable edad en Trichostrongylidae, y el tipo de manejo sanitario afectó la prevalencia de Eimeria (p=0.020); Trichostrongylidae (p=0.001); Nematodirus sp (p=0.04) y Fasciola hepatica (p=0.020). Se detectaron cargas parasitarias moderadas en todos los casos. Asimismo, se detectaron casos de biparasitisimo (26%) y multi-parasitismo (32%).

ABSTRACT The presence of gastrointestinal parasites (PGI) was determined in meat sheep from farms in the foothills of the commune of San Clemente Chile through convenience sampling (n=100) between August and November 2022. Faecal samples were collected from the rectum. and were processed using the modified Dennis sedimentation technique for the determination of F. hepatica eggs and the Sheather flotation technique for the determination of nematode and coccidia eggs. In addition, the modified McMaster quantitative technique was performed on the samples. A higher prevalence of parasites from the Trichostrongylidae family (68%) was found, followed by F. hepatica (47%), Nematodirus sp (25%) and Eimeria sp (43%). In addition, the epidemiological variables age, sex and health status were evaluated. The age group was significant (p=0.003) for the age variable in Trichostrongylidae, and the type of health management affected the prevalence of Eimeria (p=0.020); Trichostrongylidae (p=0.001); Nematodirus sp (p=0.04) and F. hepatica (p=0.020). Moderate parasite loads were detected in all cases. Likewise, cases of biparasitism (26%) and multi-parasitism (32%) were detected.

Resumen Cultivo de aliáceas comprenden diversas especies de importancia agrícola para la región Arequipa, entre ellas la cebolla es la de mayor producción en el país, sin embargo, estos cultivos son afectados por nematodos fitoparásitos entre ellas Meloidogyne spp. que ocasiona pérdidas significativas en la producción. El objetivo del presente estudio fue caracterizar al nematodo de las agallas (Meloidogyne spp) y determinar la densidad poblacional de nematodos fitoparásitos en cultivos de aliáceas en las principales localidades productoras de la región Arequipa, se colectaron muestras de raíces y suelo de cultivos de cebolla, cebolla china, poro y cebollín en las provincias de Arequipa, Castilla, Caylloma e Islay. La identificación de los géneros de nematodos se hizo mediante características morfológicas y la caracterización de Meloidogyne se hizo mediante patrones perineales y por padrón electroforético de esterasa (Est). En las 38 muestras de suelo se encontraron doce géneros de nematodos fitoparásitos: Aphelenchus, Dorylaimus, Helicotylenchus, Hemicycliophora, Meloidogyne, Mesocriconema, Mononchus, OGMA, Pratylenchus, Rotylenchus, Tylenchus, Xiphinema y nematodos de vida libre, en muestras de raíces, se encontraron ocho poblaciones de Meloidogyne spp. distribuidas en tres especies: (1) M. incognita fenotipo Est I1, Rm: 1.0 con 33,33% de frecuencia y Est I2, Rm: 1.03, 1.07 (50%); (2) M. javanica Est J3, Rm: 1.03, 1.24, 1.37 (16,67%) y una especie atípica denominada Meloidogyne sp. Rm: 0.85 (33,33%). La identificación de géneros y especies de nematodos fitoparásitos en aliáceas, permitirá adoptar medidas de manejo integrado más eficientes, debido a que poseen un comportamiento de parasitismo distinto.

Abstract Alliaceae crops includes several species of agricultural importance for the Arequipa region, among them the onion is the most produced in the country, however, these crops are affected by phytoparasitic nematodes, including Meloidogyne spp. which causes significant losses in the yield. The aim of the present study was to characterise the root-knot nematode (Meloidogyne spp) and determine the population density of phytoparasitic nematodes in alliaceae crops in the main producing localities of the Arequipa region. Samples of roots and soil were collected in onion, chinese onion, leek and chives crops in the provinces of Arequipa, Castilla, Caylloma and Islay. The identification of nematode genus was found by morphological characteristics and the characterization of Meloidogyne were performed by perineal patterns and electrophoretic pattern of esterase (Est). In the 38 soil samples, different genus of plant-parasitic nematodes was found: Aphelenchus, Dorylaimus, Helicotylenchus, Hemicycliophora, Meloidogyne, Mesocriconema, Mononchus, OGMA, Pratylenchus, Rotylenchus, Tylenchus, Xiphinema and free-living nematodes, in root samples, eight populations of Meloidogyne spp. were found. distributed among three species: (1) M. incognita phenotype Est I1, Rm: 1.0 with 33.33% of frequency and Est I2, Rm: 1.03, 1.07 (50%); (2) M. javanica Est J3, Rm: 1.03, 1.24, 1.37 (16.67%) and an atypical species named Meloidogyne sp. Rm: 0.85 (33.33%). The identification of genus and species phytoparasitic nematodes in alliaceae will allow the adoption of more efficient integrated management measures, because have a distinct parasitism behavior.