To discover new bisamide compounds with insecticidal and fungicidal activities, 19 novel cyproflanilide derivatives containing 1,2,4-oxadiazole group were designed and synthesized according to the principle of biologically active factor splicing. Preliminary biological assay data indicated that the majority of target compounds demonstrated significant insecticidal activity against Lepidopteran pests. Meanwhile, compounds 5p and 5q showed 97.22 and 100% lethality against Tetranychus cinnabarinus at 400 mg L-1, which were better than cyproflanilide (41.11% at 400 mg L-1). In addition, it is exciting that we have achieved our initial goals as some of the target compounds exhibited both insecticidal and fungicidal activities. For instance, compounds 5b and 5c showed 59.26 and 74.07% fungicidal activities against Cucumber downy mildew at 400 mg L-1, as well as 100% insecticidal activity against Plutella xylostella and armyworm at 100 mg L-1. Compound 5h showed 100% insecticidal activity against armyworm at 10 mg L-1, and also displayed 66.67% fungicidal activity against Cucumber downy mildew at 400 mg L-1. The inhibition rate of compounds 5l and 5s against Cucumber downy mildew reached 88.89 and 96.30% at 400 mg L-1. This work showed the effectively fungicidal application of 1,2,4-oxadiazole group in bisamide compounds and provides insights for optimal structural design. 1 1,2,4oxadiazole 124oxadiazole oxadiazole 1,2,4 2 4 splicing pests Meanwhile p q 9722 97 22 97.2 40 L1, L1 L 1, L-1 41.11% 4111 41 11 (41.11 L1. . L-1) addition instance b c 5926 59 26 59.2 7407 74 07 74.07 1. h 6667 66 67 66.67 l s 8889 88 89 88.8 9630 96 30 96.30 design 4oxadiazole 124 1,2, 972 9 97. L- 41.11 411 (41.1 592 5 59. 740 7 0 74.0 666 6 66.6 888 8 88. 963 3 96.3 12 1,2 41.1 (41. 74. 66. 96. 41. (41 (4 (

Abstract Introduction. Pesticides are used to control pests and diseases in agricultural activities. Improper management of these products poses a potential risk to human health and the environment. Objective. To evaluate the (eco)toxicological pressure exerted by synthetic pesticides on tobacco crops (Nicotiana tabacum) in the province of Sancti Spíritus, Cuba. Materials and methods. A database from the Provincial Directorate of Plant Health for the period 2016-2019 was used, where the pesticides assigned to the province for this crop were compared with those reported by interviewed farmers. The dual indicator POCER was used to obtain the results, determining the pressure exerted by different pesticides and their harmful reference on humans and the environment. Results. The trend in pesticide consumption (summarized in tables and graphs) showed 50 % decrease, corresponding to the country’s crop protection policy. Farmers mentioned the use of authorized and unauthorized active ingredients in the conducted surveys, and sixteen high-risk active ingredients were detected in the analyzed samples. Evaluating the POCER results and analyzed samples, a significant (eco)toxicological pressure was observed on both the environment and human health, exerted by a group of high-toxicity active ingredients used in tobacco cultivation in the province. Conclusion. Using the dual indicator POCER provides an evaluation of the (eco)toxicological pressure exerted by synthetic pesticides used in the tobacco cultivation (Nicotiana tabacum) in the province of Sancti Spíritus, Cuba, for the study period.

Resumen Introducción. Los plaguicidas son utilizados para controlar las plagas y enfermedades en las actividades agrícolas. El manejo inadecuado de estos productos constituye un riesgo potencial para la salud humana y el medio ambiente. Objetivo. Evaluar la presión toxicológica (eco) ejercida por los plaguicidas sintéticos en los cultivos de tabaco (Nicotiana tabacum) en la provincia de Sancti Spíritus, Cuba. Materiales y métodos. Se utilizó una base de datos de la Dirección Provincial de Sanidad Vegetal para el período 2016-2019, donde se tomaron los plaguicidas asignados a la provincia para este cultivo y se compararon con los declarados por los agricultores entrevistados. Para la obtención de los resultados se utilizó el indicador dual POCER, que determinó la presión ejercida por los diferentes plaguicidas y su referencia nociva sobre el ser humano y el medio ambiente. Resultados. La tendencia del consumo de plaguicidas (resumida en tablas y gráficos) mostró una disminución del 50 %, que corresponde a la política de protección de los cultivos del país. Los agricultores mencionaron el uso de ingredientes activos autorizados y no autorizados en las encuestas realizadas, y en las muestras analizadas se detectaron dieciséis ingredientes activos de alto riesgo. Al evaluar los resultados de POCER y muestras analizadas se observó que existe una gran presión (eco)toxicológica tanto para el medio ambiente como para la salud humana ejercida por un grupo de ingredientes activos de alta toxicidad utilizados en el cultivo de tabaco de la provincia. Conclusión. Con la utilización del indicador dual POCER, se obtiene una evaluación de la presión (eco)toxicológica ejercida por los plaguicidas sintéticos utilizados en el cultivo del tabaco (Nicotiana tabacum) en la provincia de Sancti Spíritus, Cuba para el período de estudio.

Abstract Introduction. Beekeeping in Honduras is an important activity for the livestock sector, threatened by the presence of pests and diseases that affect its development and production. Objective. To determine the parasitic load of Varroa destructor and Vairimorpha (Nosema) spp. associated with hygienic behavior, productivity, and the presence of other pests in Apis mellifera hives in the municipality of Tomalá, Lempira department, Honduras. Materials and Methods. A study was carried out on 57 samples from hives in 19 apiaries to determine the infestation rate of V. destructor. The average infection rate of Vairimorpha spp. was determined using the Cantwell method. Additionally, the association between parasitic loads and productivity, hygienic behavior, and the presence of other pests was determined through a stratified analysis based on whether or not treatment against Varroa spp. was used. Associations were determined using the non-parametric Mann-Whitney U and Kruskal-Wallis tests. Results. The infestation rates for V. destructor in dispersal and larval stages were 3.48 % and 6.82 %, respectively. The use of chemical treatment showed no association with the infestation rate of V. destructor in either larvae or a dults (p≥0.05). The presence of the small hive beetle (SHB) was associated with a higher infestation of V. destructor in larvae (p<0.007) in untreated hives. The infection range of Vairimorpha spp. was classified as very light with 5×104 spores per sample. The Vairimorpha spp. load showed no association with the mentioned variables (p≥0.05). Conclusion. The results indicate that varroosis is a disease of importance in the municipality of Tomalá, Lempira department, Honduras, associated with hygienic behavior and the presence of SHB in the hives. Nosemosis showed a very light infection.

Resumen Introducción. La apicultura en Honduras es una actividad importante para el sector pecuario, amenazada por la presencia de plagas y enfermedades que afectan su desarrollo y producción. Objetivo. Determinar la carga parasitaria de Varroa destructor y Vairimorpha (Nosema) spp. asociadas al comportamiento higiénico, productividad y presencia de otras plagas en colmenas de Apis mellifera en el municipio de Tomalá, departamento de Lempira, Honduras. Materiales y métodos. Se realizó un estudio en 57 muestras de colmenas de 19 apiarios, para determinar la tasa de infestación de V. destructor. La tasa media de infección de Vairimorpha spp., se determinó mediante el método de Cantwell. Además, se determinó la asociación entre las cargas parasitarias y la productividad, comportamiento higiénico y presencia de otras plagas, mediante un análisis estratificado según el uso o no de tratamiento contra Varroa spp. La determinación de asociaciones se realizó mediante las pruebas no paramétricas U de Mann Whitney y Kruskal Wallis. Resultados. Las tasas de infestación para V. destructor en fase de dispersión y larval fueron de un 3,48 % y un 6,82 %, respectivamente, el uso de tratamiento químico no mostró asociación con la tasa de infestación de V. destructor en larvas ni en adultos (p≥0,05), la presencia del pequeño escarabajo de las colmenas (PEC), se asoció con una mayor infestación de V. destructor en larvas (p<0,007) en las colmenas sin tratamiento. El rango de infección de Vairimorpha spp. se encontró dentro de la clasificación muy ligera con 5×104 esporas por muestra, la carga de Vairimorpha spp. no mostró asociación con las variables mencionadas (p≥0,05). Conclusión. Los resultados indican que varroasis es una enfermedad de importancia en el municipio de Tomalá, departamento de Lempira, Honduras, asociada con el comportamiento higiénico y la presencia de PEC en las colmenas. Nosemosis presentó una infección muy ligera.

Abstract Introduction. Evaluating onion cultivars (Allium cepa L.) in different environments to understand their adaptation is important due to the crop’s relevance in food supply across various countries, the reduction in its genetic diversity, the loss of beneficial traits, and resistance to diseases and pests. Objective. To assess the agronomic performance of onion cultivars under different environments to identify the best ones in terms of adaptation, yield, and interaction. Materials and methods. From November 2017 to August 2018, at the La Selva Research Center of the Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), Rionegro, Antioquia, Colombia, twenty-one onion cultivars plus two controls were evaluated: Peruana of the Aggregatum group and Yellow Granex of the Cepa, under open-field and protected conditions with plastic roofing, using multilocation trials in a randomized complete block design and four replications. Evaluations were consucted on categories such as bulb weight, number, length, and diameter, along with the interaction of cultivars and environments. Results. In othe open field, due to lower temperatures compared to those recorded under protected conditions resulted in higher yields of weight and number of bulbs. Under protected environments, Aggregatum group cultivars behaved as if they were from the Cepa group, producing fewer large-size bulbs. The adaptation of cultivars varied by environment: in the open field, L55 and L63 cultivars exhibited the best yields, while under protected conditions, RPT20 and RPT11 showed the best adaptation. Conclusion. Environments significantly influenced the behavior of Aggregatum group cultivars, with higher production of extra-large bulbs. Temperature contrasts in protected enviroments with plastic roofing affected cultivars yields, while open-field conditions were more favorable.

Resumen Introducción. La evaluación de cultivares de cebolla (Allium cepa L.) en diferentes ambientes para conocer su adaptación es importante debido a la relevancia del cultivo en la alimentación en diferentes países, la reducción de su diversidad genética, la perdida de sus rasgos benéficos y la resistencia a enfermedades y plagas. Objetivo. Evaluar el comportamiento agronómico de cultivares de cebolla bajo diferentes ambientes, para identificar los mejores en adaptación, rendimiento e interacción. Materiales y métodos. De noviembre 2017 a agosto de 2018, en el Centro de Investigación La Selva de la Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), Rionegro, Antioquia, Colombia, se evaluaron veintún cultivares más dos testigos de cebolla: Peruana del grupo Aggregatum y Yellow Granex del Cepa, bajo condiciones de campo abierto y protegido con techo plástico, con ensayos multilocacionales en un diseño de bloques completos al azar y cuatro repeticiones. Se evaluó por categorías: peso, número, longitud y diámetro de los bulbos; junto con la interacción de los cultivares y los ambientes. Resultados. En campo abierto, por presentar temperaturas menores a las registradas en las condiciones protegidas, se obtuvieron los mayores rendimientos de peso y número de bulbos. En ambientes protegidos, los cultivares del grupo Aggregatum, se comportaron como si fueran del grupo Cepa, al producir pocos bulbos de gran tamaño. La adaptación de los cultivares fue diferente en los ambientes: en campo abierto los cultivares L55 y L63 presentaron los mejores rendimientos, mientras que bajo condiciones protegidas, RPT20 y RPT11 fueron los que mejor se adaptaron. Conclusión. Los ambientes influyeron significativamente en el comportamiento de los cultivares del grupo Aggregatum con una mayor producción de bulbos extragrandes. Los contrastes de temperaturas que se presentaron en los ambientes protegidos con techo plástico, afectaron los rendimientos de los cultivares, mientras que las condiciones ambientales a campo abierto fueron favorables.

Abstract Introduction: The West Indian fruit fly, Anastrepha obliqua (Macquart), is one of the most economically important pests of mangoes in Mexico and the Neotropics. Objective: To analyze adult population patterns of A. obliqua and their relation to local and landscape factors. Methods: We selected 11 “Manila” mango orchards along the middle part of La Antigua River, which were characterized to determine their biophysical structure and landscape configuration considering their distance to six different land uses/land covers. Anastrepha obliqua population was estimated by collecting adult flies in colorless polyethylene plastic bottle traps baited with a protein for three weeks in June 2022. Results: A total of 1 869 adults of A. obliqua were trapped, of which 75 % were females and 25 % were males. Abundance varied from 68 to 490 adult flies per orchard, while capture frequency from 0.36 to 1.8 flies/trap/day. Abundance increased in highly shaded orchards, and capture frequency decreased in orchards with highly soil compaction. Abundance and the frequency of capture increased in orchards near isolated trees of Spondias spp. and decreased in orchards near sugarcane plantations. Shade management in mango orchards may be used as an effective strategy to promote biotic interactions to naturally regulate A. obliqua populations, meanwhile, soil compaction represents a limiting ecological condition, which might severely impact fruit fly larvae survival. Conclusions: Adult population of A. obliqua depends on several local and landscape factors because they indicate resource availability and ecological conditions. These findings could be considered for control strategies in the integrated management of this pest to promote protection and improve the fruit quality of mango crop.

Resumen Introducción: La mosca de las indias occidentales, Anastrepha obliqua (Macquart), es una de las plagas más importantes económicamente en el cultivo de mango de México y el neotrópico. Objetivo: Analizamos los patrones de la población adulta de A. obliqua y su relación con factores locales y del paisaje. Métodos: Un total de 11 huertos de mango “Manila” fueron caracterizados en estructura biofísica y configuración del paisaje. Los adultos de A. obliqua fueron capturados con trampas (botellas de polietileno cebadas con una proteína) durante tres semanas en junio de 2022. Resultados: Se capturaron 1 869 adultos de A. obliqua, de los cuales 75 % fueron hembras y 25 % machos. La abundancia varió de 68 a 490 moscas adultas por huerto, mientras que la frecuencia de captura de 0.36 a 1.8 moscas/trampa/día. La abundancia incrementó en huertos altamente sombreados y decreció en huertos con suelos compactos. La abundancia y frecuencia incrementaron en huertos cercanos a árboles de Spondias spp. y decreció en huertos cercanos a plantaciones de caña de azúcar. El manejo de la sombra puede ser utilizado como una estrategia efectiva para promover las interacciones que regulan naturalmente la población de A. obliqua, mientras que la compactación del suelo representa una condición ecológica limitante que podría impactar severamente en la supervivencia de larvas de moscas de la fruta. Conclusión: La población adulta de A. obliqua depende de varios factores locales y del paisaje que indican disponibilidad de recursos y condiciones ecológicas. Estos hallazgos podrían considerarse en las estrategias del manejo integrado de esta plaga para promover la protección y el mejoramiento de la calidad de frutos en el cultivo de mango.

ABSTRACT Crop damage-based control threshold of 12.5% has been used to reduce the excessive use of insecticides while controlling Spodoptera litura and Helicoverpa armigera in hot peppers (Capsicum annuum L.) cultivation systems. However, it is necessary to develop an easy, practical, inexpensive control threshold to increase farmer eagerness in reducing pesticide use. The study aimed to evaluate a light trap captured based-control threshold for both hot pepper pests. The activity was conducted at Lembang (ca. 1250 m a.s.l.), West Java, Indonesia, from September 2022 to April 2023. Six treatments and four replicates were arranged in a randomized block design. The treatments included the use of four light trap captured based-control thresholds, i.e., ≥ 30, ≥ 25, ≥ 20, ≥ and 15 moth trap-1 wk-1; crop damage based-control threshold of 12.5%; and once per week insecticide application as a control treatment. The study found that the implementation of pests’ control threshold of ≥ 25 moth trap-1 wk-1 could reduce 75% insecticide use compared to the plant damage-based control threshold. The use of this approach could maintain high crop production and generate a return rate of 1.26. The findings will be beneficial for farmers in reducing insecticide use.

ABSTRACT Agriculture requires new alternatives to control pests and diseases; biological controls can be a sustainable alternative for the continued success of this sector. This study was thus carried out to identify yeasts and lactic acid bacteria that have the antagonistic capacity to control three phytopathogens as Botrytis cinerea, Lasiodiplodia theobromae and Alternaria brassicae that have caused significant economic losses in agriculture. Thirteen strains of yeast and seven strains of lactic acid bacteria (LAB) were used to measure the percentage of growth inhibition, production of volatile organic compounds, production of biofilms, and the production of enzymes through a completely randomized design. The yeasts Hanseniaspora opuntiae and Saccharomyces cerevisiae and the LAB Lactococcus lactis and L. brevis stood out for their antagonistic capacity to inhibit the growth of phytopathogens by 66%, 58%, 65% and 39%, respectively. Pest and disease control highly depend on chemical phytosanitary inputs with negative economic, environmental, and social effects. This study demonstrated that the yeast H. opuntiae and the LAB L. brevis have potential as biological controls and has been observed to inhibit growth by more than 39%, providing a sustainable alternative that is less harmful to the environment and human health. To guarantee their effectivity under field conditions, their individual application, consortium application, and concentration, timing, and proper application method must be considered.

Malawi's economy heavily depends on agriculture, including both commercial and subsistence farming. Smallholder and small-medium enterprises leading the production of tomatoes in Malawi cannot satisfy local demand due to problems such as pests, diseases, unstable markets, and high costs. Many farmers lack the expertise to effectively manage these threats. To address the problem of tomato leaf disease identification, this research aimed to develop an automated system for tomato leaf disease detection by utilizing data augmentation techniques, MobileNetV3, and Convolutional Neural Network algorithms. We trained models on secondary data collected from the public PlantVillage dataset and tested the resultant classifiers on primary data of local farm images. The experimental results demonstrate that both models tested better on the PlantVillage dataset. Additionally, with an accuracy of 92.59% and a loss of 0.2805, the pre-trained MobileNetV3 model conventionally performs better than a CNN model. However, when tested on the primary field dataset, the models did not meet expectations for generalization, with the pre-trained MobileNetV3 achieving an accuracy of 9.2%, and loss of 12.91 and the CNN achieving an accuracy of 10.14% and loss of 8.11. The experiments aided in showing that the models trained on the PlantVillage dataset are not as effective when applied in real-world scenarios. Further improvements are needed to enhance the models' generalization in real-world scenarios.

Abstract: There is evidence of the high use of the neonicotinoid insecticide thiamethoxam, in tropical crops, for its effectiveness in the control of soil and plant pests. The objective of this study was to know the residuality and concentration of thiamethoxam in the papaya agroecosystem, in the main papaya fruit producing zone in the central area of the Gulf of Mexico. It was carried out during a papaya growing cycle with watermelon rotation; the taking of samples was according to the technique established by the NOM -AA-103-1988 for leaves and for fruit the NMX -FF-041-1996 by the method of quartering in papaya and watermelon, the samples were analyzed with a HPLC-UV, the data obtained were statistically analyzed by parametric and non-parametric Kruskal-Wallis tests. The presence of thiamethoxam was found in papaya and watermelon cultivation plants, the concentrations in papaya leaves reported a maximum value of 0.29 mg/kg, while for the leaves of the watermelon rotation fruit it was 0.15 mg/kg. In papaya fruit, thiamethoxam concentrations are within a range of 0.24 to 0.32 mg/kg. The concentrations and residuality of thiamethoxam mainly exceed the maximum tolerance and residuality limits of the EFSA and FAO.

Resumen: Existe evidencia del alto uso del insecticida neonicotinoide thiamethoxam en los cultivos tropicales por su efectividad en el control de plagas del suelo y la planta. El objetivo de este estudio fue conocer la residualidad y concentración del thiamethoxam en el agroecosistema de papaya en la principal zona productora de este fruto de la zona centro del Golfo de México. Este estudio se realizó durante un ciclo de cultivo de papaya con rotación de sandía; la toma de muestras se hizo según la técnica establecida por la NOM-AA-103-1988 para hojas y para fruta la NMX-FF-041-1996 mediante el método de cuarteo en papaya y sandia. Las muestras se analizaron con un equipo HPLC-UV, y los datos obtenidos se analizaron estadísticamente mediante pruebas paramétricas y no paramétricas de Kruskal- Wallis. Se encontró la presencia de thiamethoxam en la planta del cultivo de papaya y sandía. Las concentraciones en hojas de papaya reportaron como valores más altos 0.29 mg/kg, mientras que para las hojas del fruto de rotación de la sandía fue de 0.15 mg/kg. En el fruto de papaya, las concentraciones de thiamethoxam estuvieron dentro de un rango de 0.24 a 0.32 mg/kg. Las concentraciones y residualidad del thiamethoxam superan principalmente los límites máximos de tolerancia y residualidad de la EFSA y la FAO.

Abstract Among the agricultural export chains, the coffee chain represents one of the oldest in Mexico compared to those of berries, avocados, floriculture and horticulture. In recent decades, this chain has gone through a series of problems in different links, for example pests, climate changes or volatile prices. Competitiveness in foreign markets is key to guide the future production and commercialization of Mexican coffee, which is why it is necessary to know the target markets, their trends and the position that the product currently has compared to its competitors. Through the indicators of revealed comparative advantage and constant market participation, the hypothesis that Mexican coffee needs to change its market strategy, focus on quality and reorient itself towards new markets is tested. It is detected that the competitiveness in the main market, wich is the United States, is low, in addition the characteristics of consumption do not benefit Mexican coffee. In contrast, the German market represents a good opportunity, especially for quality coffees of Arabica species (Coffea arabica) such as: Typica, Bourbón, Garnica, Geisha and Caturra. In addition, these coffees are characterized by generating a greater economic benefit for the producers.

Resumen Entre las cadenas de agroexportación, la del café representa una de las más antiguas de México, comparado con las de frutillas, aguacates, floricultura y horticultura. En las últimas décadas, esta cadena atraviesa una serie de problemas en diferentes eslabones, por ejemplo, las plagas, cambios del clima o precios volátiles. La competitividad en los mercados externos es clave para orientar la futura producción y comercialización del café mexicano, por lo cual es necesario conocer los mercados objetivo, sus tendencias y la posición que tiene el producto actualmente en comparación con sus competidores. Mediante de los indicadores de ventaja comparativa revelada y la participación constante en el mercado se pone a prueba la hipótesis que el café mexicano necesita cambiar su estrategia de mercado, enfocarse en la calidad y reorientarse hacia nuevos mercados. Se detecta que la competitividad en el mercado principal, que es el estadounidense, es baja, además las características del consumo que no benefician al café mexicano. En contraste, el mercado alemán representa una buena oportunidad, sobre todo para cafés de calidad de especies arábicas (Coffea arabica) como Typica, Bourbón, Garnica, Geisha y Caturra. Además, estos cafés se caracterizan por generar una mayor derrama económica para los productores.

Resumo Entre as cadeias de agroexportação, a do café representa uma das mais antigas de México, comparado com as de morangos, abacate, floricultura e horticultura. Nas últimas décadas, esta cadeia atravessa uma série de problemas em diferentes elementos, por exemplo, as pragas, câmbios do clima ou preços volátiles. A competitividade nos mercados externos é chave para orientar a futura produção e comercialização do café mexicano, pelo qual é preciso conhecer os mercados objetivos, suas tendências e a posição que tem o produto atualmente em comparação com seus competidores. Mediante os indicadores de vantagem comparativa revelada e a participação constante no mercado é posta a prova a hipótese que o café mexicano precisa modificar sua estratégia do mercado, enfocar-se na qualidade e se re-orientar aos novos mercados. Detecta-se que a competitividade no mercado principal, que é o estadounidense, é baixa, além das características do consumo que não beneficiam ao café mexicano. Em contraste, o mercado alemão representa uma boa oportunidade, sobre tudo para cafés de qualidade de espécies árabes (Coffea arabica) como Typica, Bourbón, Garnica, Geisha e Caturra. Além disso, estes cafés caracteriza-se por gerar um maior derrame econômico para os produtores.

ABSTRACT Chinch bugs [Blissus pulchellus Montandon (Hemiptera: Blissidae)] suck the phloem from susceptible forage grasses, injecting toxins that destroy plant vessels and compromise the flow of water and nutrients, leading to plant death. Thus, the aim of this study was to assess eight forage grasses for antixenosis resistance to B. pulchellus and compare the anatomical characteristics of leaf sheath tissue from resistant and susceptible species/cultivars. Experiments were conducted in a laboratory and greenhouse, using choice and no-choice tests with the following forage grasses: Urochloa ruziziensis, U. humidicola, U. brizantha ‘Piatã’, U. brizantha ‘Paiaguás’, U. brizantha ‘Marandu’, Panicum maximum ‘Mombaça’, P. maximum ‘Zuri’, and Andropogon gayanus. The oviposition results demonstrated that in the choice test there was a change in the stink bug’s behavior in relation to grasses four hours after infestation, with U. humidicola, P. maximum ‘Mombaça’ and ‘Zuri’, U. brizantha ‘Marandu’ and A. gayanus, proving to be less attractive to insects. It is concluded that U. humidicola, P. maximum ‘Mombaça’ and ‘Zuri’, U. brizantha ‘Marandu’, and A. gayanus are less attractive to B. pulchellus. A. gayanus and P. maximum ‘Mombaça’ and ‘Zuri’ showed non-preference resistance (antixenosis) to oviposition by B. pulchellus. The resistance of U. humidicola, P. maximum ‘Zuri’, and A. gayanus to B. pulchellus may be associated with greater compaction and lignification of the parenchyma and sclerenchyma cells of leaf sheaths. Blissus Hemiptera (Hemiptera Blissidae Blissidae) nutrients death Thus B speciescultivars species cultivars species/cultivars greenhouse nochoice no ruziziensis U humidicola ‘Piatã, Piatã ‘Piatã , ‘Piatã’ ‘Paiaguás, Paiaguás ‘Paiaguás ‘Paiaguás’ ‘Marandu, Marandu ‘Marandu ‘Mombaça, Mombaça ‘Mombaça P ‘Zuri, Zuri ‘Zuri bug s infestation A insects nonpreference non preference (antixenosis sheaths

RESUMO Os percevejos-das-gramíneas [Blissus pulchellus Montandon (Hemiptera: Blissidae)] sugam a seiva de espécies forrageiras suscetíveis e injetam toxinas que destroem os vasos condutores e dificultam o transporte de água e nutrientes, levando as plantas a morte. Assim, o objetivo deste estudo foi avaliar a resistência por antixenose e tolerância em oito poáceas forrageiras à B. pulchellus e comparar as características anatômicas dos tecidos das bainhas foliares de espécies/cultivares resistentes e suscetíveis. Os ensaios foram conduzidos em laboratório e casa de vegetação, em testes com e sem chance de escolha, utilizando-se as forrageiras: Urochloa ruziziensis, U. humidicola, U. brizantha ‘Piatã’, U. brizantha ‘Paiaguás’, U. brizantha ‘Marandu’, Panicum maximum ‘Mombaça’, P. maximum ‘Zuri’, e Andropogon gayanus. Os resultados de oviposição demonstraram que no teste de escolha houve uma mudança no comportamento do percevejo em relação às gramíneas quatro horas após infestação, sendo U. humidicola, P. maximum ‘Mombaça’ e ‘Zuri’, U. brizantha ‘Marandu’ e A. gayanus menos atrativos para os insetos. Conclui-se que U. humidicola, P. maximum ‘Mombaça’ e ‘Zuri’, U. brizantha ‘Marandu’, e A. gayanus são menos atrativas a B. pulchellus. A. gayanus, e P. maximum ‘Mombaça’ e ‘Zuri’ apresentam resistência do tipo não-preferência para oviposição a B. pulchellus. A resistência de U. humidicola, P. maximum Zuri, e A. gayanus a B. pulchellus pode estar associada a maior compactação e lignificação das células dos tecidos parenquimático e esclerenquimático das bainhas foliares. percevejosdasgramíneas percevejos Blissus Hemiptera (Hemiptera Blissidae Blissidae) nutrientes morte Assim B espéciescultivares cultivares vegetação utilizandose utilizando se ruziziensis U humidicola ‘Piatã, Piatã ‘Piatã , ‘Piatã’ ‘Paiaguás, Paiaguás ‘Paiaguás ‘Paiaguás’ ‘Marandu, Marandu ‘Marandu ‘Mombaça, Mombaça ‘Mombaça P ‘Zuri, Zuri ‘Zuri infestação insetos Concluise Conclui nãopreferência não preferência

ABSTRACT Piper marginatum and Piper tuberculatum are species used for their insecticidal properties by local indigenous people in eastern Ecuador. This study aimed to determine the acaricidal and larvicidal activity of the essential oil of these species. The essential oils were obtained by hydrodistillation. The acaricidal activity was evaluated with the contact toxicity method against larvae of the tick Rhipicephalus microplus. Larvicidal activity was evaluated against Aedes aegypti mosquito larvae following WHO recommended guidelines. The essential oils of P. marginatum and P. tuberculatum showed an acaricidal potential with LC50 of 0.90 and 0.73 µL mL-1,respectively. In addition, excellent larvicidal activity was obtained with LC50 of 11.87 µL mL-1 (P. marginatum) and 8.42 µL mL-1 (P. tuberculatum) at 48 hours of evaluation. This is the first report of the acaricidal activity of P. marginatum and P. tuberculatum essential oils against R. microplus tick larvae. The results indicate that essential oils could serve as a natural alternative for controlling these pests, with ethnobotanical applications as a lice and tick repellent.

Piper marginatum y Piper tuberculatum son especies utilizadas por sus propiedades insecticidas por indígenas locales del este de Ecuador. Este estudio tuvo como objetivo determinar la actividad acaricida y larvicida del aceite esencial de estas especies. Los aceites esenciales se obtuvieron por hidrodestilación. La actividad acaricida se evaluó con el método de toxicidad por contacto frente a larvas de la garrapata Rhipicephalus microplus. Se evaluó la actividad larvicida contra larvas del mosquito Aedes aegypti siguiendo los lineamientos recomendados por la OMS. Los aceites esenciales de P. marginatum y P. tuberculatum mostraron un potencial acaricida con CL50 de 0.90 y 0.73 µL mL-1,respectivamente. Además, se obtuvo una excelente actividad larvicida con CL50 de 11.87 µL mL-1 (P. marginatum) y 8.42 µL mL-1 (P. tuberculatum) a las 48 horas de evaluación. Este es el primer reporte de la actividad acaricida de los aceites esenciales de P. marginatum y P. tuberculatum frente a las larvas de la garrapata R. microplus. Los resultados indican que los aceites esenciales podrían servir como una alternativa natural para el control de estas plagas, con aplicaciones etnobotánicas como repelente de piojos y garrapatas.

ABSTRACT The cowpea is a legume with a high nutritional value and represents one of the most important self-consumption items in the country. However, under storage conditions its main problem are bruchids, which decrease the nutritional value and fertility of the seeds. Bruchids spread more frequently unintentionally throughout the world, this is due their adaptability. In the first months of 2023, damage was observed to stored cowpea grains of the species Vigna unguiculata, presenting round holes, decreasing the nutritional value and fertility of the seeds. The inspection of grains recorded the presence of a beetle, which was identified as Decellebruchus atrolineatus, Family Chrysomelidae, Subfamily Bruchinae.

RESUMEN El poroto es una leguminosa comestible con un alto valor nutritivo y representa uno de los rubros de autoconsumo más importantes en el país. Sin embargo, en condiciones de almacenamiento su principal problema son los brúquinos, quienes disminuyen el valor nutricional y la fertilidad de las semillas. Por la adaptación que poseen, los brúquinos, se diseminan con mayor frecuencia de manera involuntaria. En los primeros meses del año 2023, fueron observados daños en granos almacenados de poroto de la especie Vigna unguiculata, presentando orificios redondeados. La inspección de dichos granos registró la presencia de un coleóptero, que fue identificado como Decellebruchus atrolineatus, Familia Chrysomelidae, Subfamilia Bruchinae.

SUMMARY: Owing to extensive overexploitation and continuous habitat loss in recent decades, Dalbergia stevensonii has become endangered in Central America and its place of origin. Genetic diversity is essential for ensuring the long-term survival of the species and is vital in breeding programs. However, knowledge of the genetic diversity of D. stevensonii is limited, as no study has been conducted to estimate the population variability in Guatemala. This study is the first to determine the genetic diversity and structure of wild populations of D. stevensonii in Guatemala using molecular markers. The genetic diversity of 90 wild D. stevensonii trees from six populations located in their natural range is currently being evaluated. Genetic diversity was moderate, with an average of 5.83 alleles per locus, a mean Shannon index value of 1.42, and observed and expected heterozygosity of 0.32 and 0.37, respectively. AMOVA indicated that only 6 % of the genetic variation was between populations, and genetic distance values (pairwise FST) suggested moderate differentiation between populations. STRUCTURE and DAPC analyses revealed the existence of three clusters for the 90 samples, while the genetic differentiation among populations is attributed more to genetics than to geographic distance. Conservation of the genetic diversity of D. stevensonii is critical to ensure its long-term survival, and the success of breeding programs focused on improving the traits and characteristics of the species, such as growth rate, wood quality, and resistance to pests and diseases. These findings provide a crucial genetic basis for conservation, management, and restoration of this endemic species.

RESUMEN: Debido a la sobreexplotación y continua pérdida de hábitats en las últimas décadas, Dalbergia stevensonii está en peligro de extinción en América Central, su lugar de origen. La diversidad genética es un factor esencial para garantizar la supervivencia de la especie a largo plazo y es vital en los programas de mejoramiento. Sin embargo, el conocimiento sobre la diversidad genética de D. stevensonii es limitado, ya que no se ha realizado ningún estudio para estimar la variabilidad de las poblaciones en Guatemala. Este es el primer estudio realizado en Guatemala para determinar la diversidad genética y la estructura de las poblaciones silvestres de D. stevensonii utilizando marcadores moleculares. Actualmente, se está evaluando la diversidad genética de 90 árboles silvestres de D. stevensonii procedentes de seis poblaciones situadas en su área de distribución natural. La diversidad genética es moderada, con una media de 5,83 alelos por locus, un valor medio del índice de Shannon de 1,42 y una heterocigosidad observada y esperada de 0,32 y 0,37 respectivamente. El análisis AMOVA mostró que solamente el 6 % de la variación genética se presenta entre poblaciones, y los valores de distancia genética (FST por pares) sugieren una diferenciación moderada entre poblaciones. Los análisis STRUCTURE y DAPC revelaron la existencia de tres conglomerados para las 90 muestras, mientras que las diferenciaciones genéticas entre poblaciones se atribuyeron más a la distancia genética que a la geográfica. La conservación de la diversidad genética de D. stevensonii es fundamental para garantizar su supervivencia a largo plazo y el éxito de los programas de mejoramiento centrados en la mejora de los rasgos y características de la especie, como la tasa de crecimiento, la calidad de la madera y la resistencia a plagas y enfermedades. Estos hallazgos proporcionan una base genética crucial para la conservación, gestión y restauración de esta especie endémica.

Abstract Plant fertilization may impact directly on insect pest behavior and biology. Fertilization may be accomplished by using synthetic mineral or organic fertilizers. The effect of different doses of boiled hen chicken manure, Penergetic®, Bokashi compound and mineral fertilizer on the adult population of Bemisia tabaci and Myzus persicae on collards leaves were evaluated. The experiment was conducted in the greenhouse using the treatments: Bokashi, Penergetic® bioactivator, 2.5%, 5%, and 7.5% of solution of boiled manure, mineral fertilization and control. The number of insects was counted directly on the leaves, and the nitrogen, potassium content, and total phenolic compound in the leaves were determined. Higher populations of Bemisia tabaci and M. persicae were observed on NPK-fertilized plants compared to other treatments. Higher levels of nitrogen foliar were found for Bokashi-fertilized plants; and higher concentrations of total phenolic compounds were found in the control. A negative correlation between total phenolics and B. tabaci was established suggesting the importance of these compounds in the species development. The results indicate the importance of the source of the fertilization for sustainable pest management.

Resumen La fertilización de las plantas puede tener un impacto directo en el comportamiento y la biología de los insectos plaga. La fertilización se puede lograr utilizando fertilizantes minerales sintéticos u orgánicos. Se evaluó el efecto de diferentes dosis de estiércol de gallina hervido, Penergetic®, compuesto Bokashi y fertilizante mineral sobre la población adulta de Bemisia tabaci y Myzus persicae en hojas de col forrajera. El experimento se realizó en invernadero utilizando los tratamientos: Bokashi, bioactivador Penergetic®, 2.5%, 5% y 7.5% de solución de estiércol hervido, fertilización mineral y el control. El número de insectos se contó directamente en las hojas, y se determinó el contenido de nitrógeno, de potasio y los compuestos fenólicos totales en las hojas. Se observaron poblaciones más altas de Bemisia tabaci y M. persicae en plantas fertilizadas con NPK en comparación con otros tratamientos. Se encontraron niveles más altos de nitrógeno foliar para las plantas fertilizadas con Bokashi; y se encontraron mayores concentraciones de compuestos fenólicos totales en el control. Se estableció una correlación negativa entre los fenólicos totales y B. tabaci, lo que sugiere la importancia de estos compuestos en el desarrollo de la especie. Los resultados indican la importancia de la fuente de fertilización para el manejo sustentable de plagas.