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Ambrosia beetles from the tribe Xyleborini are part of nearly all forest ecosystems. Because of their small size, haplodiploid mating structure, and protected lives inside the sapwood of woody plants, they have a unique ability to expand into new regions via inadvertent human transport. A small number of invasive xyleborines cause significant damage to forests, lumber concerns, and agricultural systems. Most ambrosia pests damage or kill trees by the accumulation of beetle attacks, one is known to cause tree death through the introduction of pathogenic fungus into susceptible Lauraceae trees. The relationships between ambrosia fungi and their beetle vectors range from mutualistic symbiosis to facultative association, but most remain unstudied. Unresolved taxonomies, convergent morphologies, and the difficulty of sampling ambrosia fungi over their entire global ranges make comprehensive surveys of ambrosia fungi difficult to achieve. Ambrosia fungi from Europe and North America are moderately well documented, however, we have yet to sufficiently document those from Africa, Asia, Australia, and South America. Worldwide cooperation to improve and standardize scientific study of the ambrosia symbioses is needed to better understand these impactful organisms.

Nematophagous fungi can feed on nematodes under nutrient-poor conditions. They live in the soil and their study is important because of their possible use in the biocontrol of phytoparasitic nematodes. These fungi can be cultivated in the laboratory using different media and substrates, making them potential agents for agricultural use in tropical environments. The objective was to review recent scientific advances in the ecological interactions of nematophagous fungi and their prey, with emphasis on their use as biological controllers. Given the importance of their interactions in the soil, diversity, abundance, dispersal, and colonization of different types of habitats, these fungal microorganisms can be specialists or generalists in the predation of nematode populations in their various stages (egg, juvenile or adult). The different scientific advances and applications of predatory fungi in some tropical crops in Latin American countries are also briefly described. After these explorations, it is possible to conclude that the integrated application of microorganisms in the soil could improve the production of some cultivars by efficiently reducing nematode populations. In addition, it could improve the structure of soil trophic interactions, with environmentally benign treatments that reduce the use of chemical pesticides.

Resumen El objetivo de este estudio fue determinar la fluctuación poblacional de Premnobius cavipennis y el efecto de la altura de trampa en plantaciones de balso (Ochroma pyramidale) en las localidades de El Vergel, El Empalme y Guapara en Ecuador. Se usaron trampas de intercepción de vuelo con alcohol como atrayente, colocadas a uno, cuatro y ocho metros de alto. La recolecta y evaluación se realizó cada semana durante un año por localidad. Las poblaciones de P. cavipennis, fluctuaron durante el año, con máximas poblacionales en el periodo lluvioso en las tres localidades. En El Vergel se encontró mayor abundancia con 2.382 individuos, máxima poblacional en diciembre. En El Empalme se capturaron 1.263 individuos, con alzas poblacionales en enero y abril. En Guapara se registraron 525 individuos, con un pico poblacional en marzo. Los individuos de P. cavipennis se capturaron en las tres alturas de las trampas en las tres localidades. Hubo diferencias altamente significativas entre las alturas con un mayor efecto de altura de trampa en la captura de individuos a un metro, comportamiento que fue igual en las tres localidades. Abstract This study aimed to determine the population fluctuation of Premnobius cavipennisand the effect of the trap height on balsa plantations (Ochroma pyramidale). The research was in El Vergel, El Empalme, and Guapara, three localities of Ecuador. There were used flight-interception traps with alcohol as an attractant, placed at one, four, and eight meters high. The collection and evaluation were carried out every week, for one year by locality. Premnobius cavipennis showed a population fluctuation throughout the year, with population peaks in months of the rainy season in the three locations. In El Vergel, the greatest abundance of P. cavipennis was found with 2,382 individuals, showing a population maximum in December. In El Empalme 1,263 individuals were captured, with population increases in January and April. In Guapara 525 individuals were registered, showing a population increase in March. There were captured individuals of P. cavipennis in the three heights of the traps in the three locations. There were highly significant differences between the heights, with a greater effect on the capture at one meter in the three locations of individuals at one meter, behavior that was the same in the three locations.

espanolLos polinizadores naturales cumplen un rol importante en la eficiencia reproductiva de Theobroma cacao. El objetivo de esta investigacion fue determinar la cantidad y diversidad de insectos en T. cacao tipo Nacional, en sistema monocultivo y sistema agroforestal, con enfasis en los polinizadores. El estudio se realizo en finca experimental “La Represa” ubicada en el canton Quevedo, provincia Los Rios, Ecuador. Se colocaron trampas de emergencia y captura de insectos en los dos sistemas de cultivo. Ademas, se realizaron observaciones directas en las flores de T. cacao para registrar la presencia de insectos polinizadores. Los insectos capturados se identificaron con la ayuda de claves entomologicas, lupa, y estereomicroscopio. Se calculo el indice de dominancia y diversidad Simpson e indice de similitud de Jaccard. Los mayores porcentajes de insectos se obtuvieron del orden Hymenoptera (76.99%), Coleoptera (10.21%) y Diptera (7.95%). El indice Simpson fue de 0.58 y 0.42 para dominancia y diversidad, respectivamente. La similitud segun Jaccard fue del 24% de las familias de insectos en los sistemas de produccion. Se registro una sola familia (Cecidomyiidae) como un posible polinizador en T. cacao en el area de estudio. Hay baja diversidad y alta dominancia de insectos para los sistemas de produccion analizados. Uno de los factores climaticos que influye en la presencia de los insectos capturados en T. cacao es la humedad relativa, pues se encontro una relacion directa positiva entre estas dos variables EnglishNatural pollinators follow an important role in the reproductive efficiency of Theobroma cacao L. The objective of this research was to determine the quantity and diversity of insects in T. cacao National Type, in monoculture system and agroforestry system, with emphasis on pollinators. The study was carried out in the experimental farm “La Represa” located in the city Quevedo, province Los Rios, Ecuador. Emergency traps and insect capture were placed in the two farming systems. In addition, direct observations were made on the flowers of T. cacao to record the presence of pollinating insects. The captured insects were identified with the help of entomological keys, magnifying glass, and stereomicroscope. The Simpson dominance and diversity index and Jaccard similarity index were calculated. The highest percentages of insects were obtained from the order Hymenoptera (76.99%), Coleoptera (10.21%) and Diptera (7.95%). The Simpson index was calculated at 0.58 and 0.42, and Jaccard’s similarity was 24% among insect families found in both production systems. A single family (Cecidomyiidae) was recorded as a possible pollinator in T. cacao in the study area. There is low diversity and high dominance of insects for the production systems analyzed. One of the climatic factors that influences the presence of the insects captured in T. cacao is the relative humidity, since a positive direct relationship was found between these two variables

Coptoborus ochromactonus Smith and Cognato is a recently described xyleborine ambrosia beetle pest associated with balsa, Ochroma pyramidale (Cav. Ex Lam.) Urb., in Ecuador. This pest has caused significant loss of cultivated balsa in Ecuador, but little is known of its biology and ecology. Based on examination of multiple gallery systems, this study describes the gallery pattern and life cycle of C. ochromactonus and confirms the generic identity of the symbiotic fungus. Females initiated attack, excavating a gallery perpendicular to the bole. The primary tunnel branched into a secondary tunnel at a mean 3.13 mm. This first secondary tunnel was excavated in a horizontal plane between the phloem and xylem for a mean 18.0 mm. Along its length, two tertiary tunnels were constructed on each side, measuring a mean 26.0 and 20.0 mm, respectively. Conidiophores and conidia of an unidentified Fusarium sp. grew on the tunnel walls and were fed upon by the beetle and her progeny. Coptoborus ochromactonus exhibits sexual dimorphism. The female is 2.6 mm long and possesses a round pronotum, whereas the male is 2.2 mm long and has a quadrate pronotum. The developmental stages last a mean 6, 14, 6, 4 and 30 d for egg, larva, pupa, teneral adult, and adult, respectively, when reared at 25°C. Three larval instars were present, with mean head capsule widths of 0.23, 0.31, and 0.42 mm, respectively. In general, the life cycle of C. ochromactonus is similar to those described for other xyleborine ambrosia beetle species.

Knowledge about pollen biology is fundamental for the planning of controlled crosses in programs of conservation and genetic improvement of plant species. The objectives of this research were to determine the ideal medium for in vitro germination of pollen and to evaluate the effect of temperature and drying on the viability of stored pollen from Ochroma pyramidale. Pollen was obtained from flowers collected before anthesis. The appropriate culture medium for in vitro germination of pollen was determined by testing modifications of the medium proposed by Brewbaker and Kwack. Pollen drying was performed during different times (60, 120, 180 and 240 minutes) at 29 °C and 45 % relative humidity. These samples were stored under temperatures of 5, -20 and -196 °C, and evaluated for 45 days. The ideal medium for pollen germination was composed of 10 % sucrose, 30 mg L-1 boric acid, 430 mg L-1 calcium nitrate. The initial viability calculated by in vitro germination was high, which indicates that the individuals evaluated can be used as pollen donors in the controlled crossing plans. Humidity below 5 % allowed keeping the pollen stored, independently of the storage temperature during the 45 days of the test, without significant decrease in their viability and germination rate. However, pollen viability decreased rapidly when it was stored with high moisture content, regardless of storage temperatures., El conocimiento sobre la biología del polen es fundamental para la planificación de cruzamientos controlados en programas de conservación y mejoramiento genético de especies vegetales. Esta investigación tuvo como objetivos determinar el medio idóneo para la germinación in vitro de polen y evaluar el efecto de temperatura y secado en la viabilidad de polen almacenado de Ochroma pyramidale. El polen se obtuvo de flores colectadas previo a la antesis. El medio de cultivo adecuado para realizar la germinación in vitro del polen se determinó probando modificaciones del medio propuesto por Brewbaker y de Kwak (BK). El secado del polen se realizó durante diferentes tiempos (60, 120, 180 y 240 minutos) a 29 °C y 45 % de humedad relativa; estas muestras fueron almacenadas bajo temperaturas de 5°, -20 °C y -196 °C, y evaluadas durante 45 días. El medio idóneo para la germinación del polen estuvo compuesto por 10 % de sacarosa, 30 mg L-1 ácido bórico, 430 mg L-1 nitrato de calcio. La viabilidad inicial calculada mediante germinación in vitro fue alta, lo que indica que los individuos evaluados se pueden utilizar como donantes de polen en los planes de cruzamiento controlado. La humedad por debajo del 5 % permitió mantener el polen almacenado, sin disminución significativa de su viabilidad y tasa de germinación, durante los 45 días del ensayo, independientemente de la temperatura de almacenamiento. No obstante, la viabilidad del polen disminuyó rápidamente cuando fue almacenado con alto contenido de humedad, independientemente de las temperaturas de almacenamiento.

The species of Scolytinae subfamily have a worldwide distribution, and are found mainly in the Neo-tropic regions. They usually dominate the communities of wood borer insects. The aim of the present study was to determine the diversity among Scolytinae species associated with balsa, teak, rubber and gamhar plantations located in the humid tropical zone of the Ecuadorian littoral. In each plantation seven flight interception traps containing an ethanol / gel mixture were installed, with a collection frequency of 15 days for three months in the dry period. A total of 1437 specimens were collected, represented by Xyleborini, Cryphalini, Corthylini and Ipini tribes. In the four plantations, 18 species of Scolitids were collected, of which 16 were recorded in the balsa plantation, while in the other plantations 10 to 12 species were found. The most abundant Scolitids were Hypothenemus spp., Corthylus spp., Xyleborus affinis, Xyleborinus bicornatulus and Premnobium cavipennis. The Shannon-Wiener diversity index was higher in the balsa culture (H’= 2.37) and lower in Teak (H’= 1.57). The Jaccard similarity index was higher among the teak and rubber plantations (Cj = 0.9090) while the balsa plantation obtained less similarity with respect to the other three plantations. The greatest diversity of Scolitids was recorded in the balsa plantation, which is a native species, unlike the other forest species, which are exotic, indicating that the diversity would be influenced by the host tree and the location where they are found. The species of Scolytinae subfamily have a worldwide distribution, and are found mainly in the Neo-tropic regions. They usually dominate the communities of wood borer insects. The aim of the present study was to determine the diversity among Scolytinae species associated with balsa, teak, rubber and gamhar plantations located in the humid tropical zone of the Ecuadorian littoral. In each plantation seven flight interception traps containing an ethanol / gel mixture were installed, with a collection frequency of 15 days for three months in the dry period. A total of 1437 specimens were collected, represented by Xyleborini, Cryphalini, Corthylini and Ipini tribes. In the four plantations, 18 species of Scolitids were collected, of which 16 were recorded in the balsa plantation, while in the other plantations 10 to 12 species were found. The most abundant Scolitids were Hypothenemus spp., Corthylus spp., Xyleborus affinis, Xyleborinus bicornatulus and Premnobium cavipennis. The Shannon-Wiener diversity index was higher in the balsa culture (H’= 2.37) and lower in Teak (H’= 1.57). The Jaccard similarity index was higher among the teak and rubber plantations (Cj = 0.9090) while the balsa plantation obtained less similarity with respect to the other three plantations. The greatest diversity of Scolitids was recorded in the balsa plantation, which is a native species, unlike the other forest species, which are exotic, indicating that the diversity would be influenced by the host tree and the location where they are found.

Resumen En el control de plagas agrícolas, los insecticidas representan la principal alternativa disponible. Para analizar la magnitud de su uso, se realizaron 539 entrevistas a agricultores en los siguientes cultivos: Cucurbitaceae: melón, Cucumis melo, y sandía, Citrullus lanatus; Fabaceae: frijol, Phaseolus vulgaris; Solanaceae: papa, Solanum tuberosum, pimiento, Capsicum annuum, y tomate, Solanum lycopersicum, ubicados en las provincias Chimborazo, El Oro, Guayas, Loja y Santa Elena, en Ecuador. Se recabó información sobre plagas importantes, tipo de manejo y si resultaba plaguicida químico, y se consignaba nombre genérico, ingrediente activo, toxicidad aguda, dosificación aplicada, frecuencia de aspersiones, periodos de carencia y mezclas de productos. El total de los entrevistados manifestó utilizar mezclas de insecticidas, generalmente elevando las dosifi- caciones recomendadas sin tomar en cuenta los periodos de carencia. Además, señalaron realizar 2,6, 1,1, 0,5, 2,0 y 2,8 aspersiones semanales en promedio para cucurbitáceas (melón y sandía), frijol, papa, pimiento y tomate, respectivamente. Las plagas principales mencionadas fueron áfidos (Hemiptera: Aphididae) en cucurbitáceas y pimiento; Liriomyza spp. en frijol (Diptera: Agromyzidae), Premnotrypes vorax (Coleoptera: Curculionidae) en papa y Prodiplosis longifila (Diptera: Cecidomyiidae) en tomate. Aproximadamente el 80 % de los insecti- cidas utilizados pertenecen a las Clase I y II. Los resultados indicaron altas frecuencias de aspersiones, dosificaciones elevadas y alta toxicidad para verte- brados en los insecticidas usados. Dado el impacto de los insecticidas, es necesario estudiar los desequi- librios en los agroecosistemas, efectos en la salud y el ambiente, así como validar alternativas ecológicas y socioeconómicamente más racionales. Abstract In agricultural pest control, insecticides represent the main available alternative. To analyze the magnitude of its use, 539 interviews to farmers were carried out considering the following crops: Cucurbitaceae: melon, Cucumis melo, and watermelon, Citrullus lanatus; Fabaceae: common bean, Phaseolus vulgaris; Solanaceae: potato, Solanum tuberosum, pepper, Capsicum annuum and tomato, Solanum lycopersicum, located in the provinces of Chimborazo, El Oro, Guayas, Loja and Santa Elena. Information was requested on important pests and type of manage- ment; if chemical pesticides were used, the following information was registered: Generic name, the active ingredient, acute toxicity, dosage, spraying frequency, waiting periods, and product mixture. All interviewed farmers expressed the use of insec- ticide mixtures, raising the recommended dosages without considering the waiting periods of each product. Additionally, farmers reported 2.6, 1.1, 0.5, 2.0, and 2.8 weekly aspersions for cucurbits (melon and watermelon), common bean, potato, pepper, and tomato, respectively. The main pests mentioned were: aphids (Hemiptera: Aphididae) in cucurbits and pepper, Liriomyza spp. (Diptera: Agromyzidae) in common bean, Premnotrypes vorax (Coleoptera: Curculionidae) in potato and Prodiplosis longifila (Diptera: Cecidomyiidae) in tomato. Approximately 80 % of the insecticides used belong to Class I and II. The results indicated high spraying frequencies, high dosages and high toxicity for vertebrates with the insecticides used by farmers. Given the impact of insecticides, it is necessary to study imbalances in agroecosystems, effects on health, and also on the environment, as well as to validate more rational ecological and socio-economic alternatives.

Nothofagus alpina es una de las especies forestales más importantes del Sur de Chile y Argentina, países donde se ha empezado con programas de mejoramiento genético. La micropropagación es una técnica muy útil en la clonación de árboles con fines de mejoramiento, por tanto, los objetivos planteados en esta investigación fueron: determinar la mejor concentración de fitohormonas 6-bencilaminopurina (BAP) y ácido indol butírico (AIB) y, el medio de cultivo idóneo para inducir el enraizamiento de brotes y la brotación de secciones nodales de N. alpina. Se evaluaron los medios de Murashige Skoog (MS) y Wood Plant Medium (WPM), con la mitad de los macronutrientes (enraizamiento) y los micronutrientes completos (multiplicación), suplementado con peptone (0.1%), sacarosa (2.0%), agar (0.7%) y diferentes concentraciones de auxinas. El medio MS suplementado con 2 mg L-1 de AIB resultó mejor para inducir la producción de las raíces, tanto en número como en la longitud de la raíz principal. El mayor porcentaje de enraizamiento se registró en el medio WPM suplementado con 2 mg L-1 AIB. Los tratamientos para inducir multiplicación que incluyeron citoquinina originaron callos y no enraizaron; siendo mayor la presencia de callos en el medio WPM. Se sugiere que la aplicación de citoquininas no es indispensable para la brotación, puesto que en los tratamientos testigos hubo una buena brotación; lo que hace suponer que el material vegetal utilizado tiene suficiente niveles endógenos de esta fitohormona.