Fagodisuasión de extractos deBrugmansia candida(Solanaceae) en larvas deHypsipyla grandella(Lepidoptera: Pyralidae) / Phagodeterrence of extracts ofBrugmansia candida(Solanaceae) onHypsipyla grandella(Lepidoptera: Pyralidae) larvae

Resumen Hypsipyla grandellaes una plaga forestal clave en América Latina y el Caribe, donde ha impedido todo intento de establecer plantaciones comerciales de caobas (Swieteniaspp.) y cedros (Cedrelaspp.). En la búsqueda de métodos de manejo de sus larvas, que sean preventivos y rentables, así como basados en recursos de la flora tropical, fue evaluada la actividad fagodisuasiva del extracto crudo y de cuatro particiones fitoquímicas (agua, hexano, diclorometano y acetato de etilo) de la flor de reina de la noche,Brugmansia candida(Solanaceae). Se efectuaron bioensayos de laboratorio con concentraciones crecientes del extracto crudo (0.1; 0.3; 1.0; 3.2 y 10.0 % m/v) y con cada una de las particiones (según el rendimiento del proceso de particionamiento). Se utilizó un diseño de bloques completos al azar, con cuatro repeticiones, y se expusieron larvas de instar III de H. grandellaa discos de cedro amargo (Cedrela odorata) impregnados con el respectivo tratamiento, por 24 h. Se midió el porcentaje de consumo de cada disco. El extracto crudo y la partición de hexano, mostraron un evidente efecto fagodisuasivo a partir de concentraciones de 1.0 % y 0.122 % m/v, respectivamente. También se realizó un bioensayo para comparar una sola concentración (0.38 % m/v) del alcaloide escopolamina, el cual redujo en 90% el consumo con respecto a los testigos. Asimismo, se evaluó la mortalidad y los efectos subletales en larvas expuestas al extracto crudo, la partición de hexano y la escopolamina, pero no hubo evidencias de ellos, lo que confirmó su acción fagodisuasiva. Además, se realizó un tamizaje fitoquímico del extracto crudo, y mediante pruebas cualitativas se determinó que los alcaloides, taninos, triterpenos y cumarinas fueron los metabolitos secundarios más importantes. Finalmente, se confirmó la presencia de la escopolamina tanto en el extracto crudo como en la partición de hexano, mediante el método de cromatografía de gases acoplado a un espectrómetro de masas (GC-MS). Se recomienda preparar una formulación de escopolamina más algunos coadyuvantes, y evaluar su eficacia en condiciones de invernadero, como un primer paso para avanzar en el desarrollo de un fagodisuasivo comercial.

Abstract Hypsipyla grandella is a key forest pest in Latin America and the Caribbean, where it has precluded attempts to establish commercial plantations of mahoganies (Swieteniaspp.) and cedars (Cedrelaspp.). In the search for methods to manage its larvae, being both preventative and cost-effective, as well as based upon resources from tropical flora, the crude flower extract of angel's trumpet, Brugmansia candida, as well as four partitions thereof (water, hexane, dichlorometane, and ethyl acetate), were tested for phagodeterrence. Laboratory bioassays involved increasing concentrations of the crude extract (0.1, 0.3, 1.0, 3.2 and 10.0 % w/v) as well as each one of the partitions (in accordance to the yield obtained from the partitioning process). A randomized complete block design, with four replicates, was used. H. grandellainstar III larvae were exposed for 24 h to Spanish cedar (Cedrela odorata) leaf discs dipped into the respective treatment, after which disc consumption was measured. Strong phagodeterrence was detected at concentrations as low as 1.0 % y 0.122 % w/v for the crude extract and the hexane partitions, respectively. In addition, a single bioassay was performed to compare a single concentration (0.38 % w/v) of the alkaloid scopolamine, which reduced consumption in 90 % with respect to the controls. Also, mortality and sublethal effects were assessed in larvae exposed to the crude extract, the hexane partition and scopolamine, with no evidence for them, which confirmed their phagodeterrence. Moreover, the crude extract was submitted to a phytochemical screening by means of a number of qualitative tests, which showed that alkaloids, tannins, triterpenes and cumarins were the most important secondary metabolites. Finally, the presence of scopolamine was confirmed in both the crude extract and the hexane partition, by means of the gas chromatography-spectrometry (GC-MS) analytical method. It is recommended to prepare a formulation of scopolamine plus some adjuvants, in order to test its effectiveness under greenhouse conditions, as a first step to advance in the development of a commercial phagodeterrent. Rev. Biol. Trop. 66(1): 58-69. Epub 2018 March 01.

[Phagodeterrence by a crude extract of common rue (Ruta chalepensis, Rutaceae) and its partitions on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae]. / Fagodisuasión de un extracto de ruda (Ruta chalepensis, Rutaceae) y sus particiones sobre larvas de Hypsipyla grandella (Lepidoptera: Pyralidae).

Hypsipyla grandella (Zeller) larva is maybe the main forest pest in Latin America and the Caribbean, as it bores into the main shoot of trees providing precious woods, such as mahoganies (Swietenia spp.) and cedars (Cedrela spp.). In the search for a preventative method for managing it, the crude leaf extract of common rue (Ruta chalepensis L.), as well as four partitions thereof (water, hexane, dichlorometane, and ethyl acetate), were tested for phagodeterrence. Laboratory bioassays involved increasing concentrations of the crude extract (0.1, 0.32, 1.0, 3.20 and 10.0%w/v) as well as each one of the partitions (in accordance to the yield obtained from the partitioning process), plus rutin, a flavone glycosid. A randomized complete block design, with four replicates, was used. H. grandella instar III larvae were exposed for 24 h to cedar (Cedrela odorata) leaf discs dipped into the respective treatment, after which disc consumption was measured. Strong phagodeterrence was detected at concentrations as low as 0.32 and 0.074%w/v for the crude extract and the hexane partitions, respectively; the ethyl acetate (0.24%w/v) and the water partition (for all of its concentrations), as well as the rutin (starting at 0.064%w/v), caused phagodeterrence, too. Moreover, the crude extract was submitted to a phytochemical screening by means of a number of qualitative tests, to determine possible metabolites causing phagodeterrence, the most important being alkaloids, triterpenes, coumarins and rutin. A particular phytochemical screening was carried out for the hexane partition, which was the most active.

[Phagodeterrent and systemic activity of a fomulation derived from an extract of common rue (Ruta chalepensis, Rutaceae) on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae]. / Actividad fagodisuasiva y sistémica de una formulación derivada de un extracto de ruda (Ruta chalepensis, Rutaceae) sobre larvas de Hypsipyla grandella (Lepidoptera: Pyralidae).

A key neotropical pest of mahoganies (Swietenia spp.) and cedars (Cedrela spp.), the larva of Hypsipyla grandella (Zeller) commonly bores into the main shoot of these valuable timber species, causing forking of the stems. Therefore, it would be desirable to count upon a phagodeterrent and systemic product which could readily protect young tissues. Since crude extracts of common rue foliage (Ruta chalepensis L.) have phagodeterrent activity on H. grandella larva, a product was formulated by combining such an extract with a number of coadjuvants, and was assessed on 75-100 cm tall Spanish cedar (Cedrela odorata L.) trees, inside a greenhouse. A completely randomized design was used, with 10 trees per each one of the following treatments: the formulated product, an absolute control (distilled water), a relative control (carbofuran, 1%m/v in water), and the relative control without the crude extract. Number of attacks to the main shoot, fallen leaves and frass piles were recorded, as well as tunnel length. Regarding these variables, the formulated product provided excellent protection to treated trees, with only 0.1 attacks to the main shoot, on the average, at the end of the evaluation period. Likewise, when the systemic activity of the crude extract was assessed, substances present in it were able to translocate and get assimilated by the trees, thereafter causing phagodeterrence to larvae. Finally, an espectrophotometry analysis (performed at a wavelength of 355 nm) allowed us to determine the concentration (403+/-1 mg/l) and percentage (0.40%) of the flavonoid rutin in the crude extract, which eventually may be used as an analytical marker compound, should an industrial formulation be developed.

Fagodisuasión de un extracto de ruda (Ruta chalepensis, Rutaceae) y sus particiones sobre larvas de Hypsipyla grandella (Lepidoptera: Pyralidae)

Phagodeterrence by a crude extract of common rue (Ruta chalepensis, Rutaceae) and its partitions on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae. Hypsipyla grandella (Zeller) larva is maybe the main forest pest in Latin America and the Caribbean, as it bores into the main shoot of trees providing precious woods, such as mahoganies (Swietenia spp.) and cedars (Cedrela spp.). In the search for a preventative method for managing it, the crude leaf extract of common rue (Ruta chalepensis L.), as well as four partitions thereof (water, hexane, dichlorometane, and ethyl acetate), were tested for phagodeterrence. Laboratory bioassays involved increasing concentrations of the crude extract (0.1, 0.32, 1.0, 3.20 and 10.0%w/v) as well as each one of the partitions (in accordance to the yield obtained from the partitioning process), plus rutin, a flavone glycosid. A randomized complete block design, with four replicates, was used. H. grandella instar III larvae were exposed for 24 h to cedar (Cedrela odorata) leaf discs dipped into the respective treatment, after which disc consumption was measured. Strong phagodeterrence was detected at concentrations as low as 0.32 and 0.074%w/v for the crude extract and the hexane partitions, respectively; the ethyl acetate (0.24%w/v) and the water partition (for all of its concentrations), as well as the rutin (starting at 0.064%w/v), caused phagodeterrence, too. Moreover, the crude extract was submitted to a phytochemical screening by means of a number of qualitative tests, to determine possible metabolites causing phagodeterrence, the most important being alkaloids, triterpenes, coumarins and rutin. A particular phytochemical screening was carried out for the hexane partition, which was the most active. Rev. Biol. Trop. 58 (1): 1-14. Epub 2010 March 01.

La larva de Hypsipyla grandella (Zeller) es quizás la principal plaga forestal en América Latina y el Caribe, por perforar el brote principal de árboles de maderas reciosas, como caobas (Swietenia spp.) y cedros (Cedrela spp.). En la búsqueda de un método preventivo para su manejo, se estudió la actividad fagodisuasiva del extracto crudo y de cuatro particiones fitoquímicas (agua, hexano, diclorometano y acetato de etilo) del follaje de ruda (Ruta chalepensis L.). Se realizaron bioensayos de laboratorio con concentraciones crecientes del extracto crudo (0.1; 0.32; 1.0; 3.20 y 10.0%m/v) y con cada una de las particiones (según el rendimiento del proceso de particionamiento), así como con el glicósido flavónico rutina. Para ello se empleó un diseño de bloques completamente al azar, con cuatro repeticiones y se expusieron larvas de instar III de H. grandella a discos de cedro (Cedrela odorata) impregnados con el respectivo tratamiento, por 24h. Se midió el porcentaje de consumo de cada disco. Hubo un fuerte efecto fagodisuasivo en el extracto crudo y en la partición hexano, a concentraciones tan bajas como 0.32% y 0.074% m/v, respectivamente; las particiones de acetato de etilo (0.24%m/v) y la acuosa (en todas sus concentraciones), así como la rutina (a partir del 0.064%m/v) también causaron fagodisuasión. Además, se realizó un tamizaje fitoquímico del extracto crudo, utilizando varias pruebas cualitativas para detectar la presencia de los principales grupos de metabolitos secundarios, entre los cuales los más importantes fueron alcaloides, triterpenos, cumarinas y la rutina. Asimismo, se realizó una marcha fitoquímica a la partición hexano, por ser la más activa.

Actividad fagodisuasiva y sistémica de una formulación derivada de un extracto de ruda (Ruta chalepensis, Rutaceae) sobre larvas de Hypsipyla grandella (Lepidoptera: Pyralidae)

Phagodeterrent and systemic activity of a fomulation derived from an extract of common rue (Ruta chalepensis, Rutaceae) on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae. A key neotropical pest of mahoganies (Swietenia spp.) and cedars (Cedrela spp.), the larva of Hypsipyla grandella (Zeller) commonly bores into the main shoot of these valuable timber species, causing forking of the stems. Therefore, it would be desirable to count upon a phagodeterrent and systemic product which could readily protect young tissues. Since crude extracts of common rue foliage (Ruta chalepensis L.) have phagodeterrent activity on H. grandella larva, a product was formulated by combining such an extract with a number of coadjuvants, and was assessed on 75-100cm tall Spanish cedar (Cedrela odorata L.) trees, inside a greenhouse. A completely randomized design was used, with 10 trees per each one of the following treatments: the formulated product, an absolute control (distilled water), a relative control (carbofuran, 1%m/v in water), and the relative control without the crude extract. Number of attacks to the main shoot, fallen leaves and frass piles were recorded, as well as tunnel length. Regarding these variables, the formulated product provided excellent protection to treated trees, with only 0.1 attacks to the main shoot, on the average, at the end of the evaluation period. Likewise, when the systemic activity of the crude extract was assessed, substances present in it were able to translocate and get assimilated by the trees, thereafter causing phagodeterrence to larvae. Finally, an espectrophotometry analysis (performed at a wavelength of 355nm) allowed us to determine the concentration (403±1mg/l) and percentage (0.40%) of the flavonoid rutin in the crude extract, which eventually may be used as an analytical marker compound, should an industrial formulation be developed. Rev. Biol. Trop. 58 (1): 15-29. Epub 2010 March 01.

Para el manejo de Hypsipyla grandella (Zeller), cuya larva barrena el brote principal de caobas (Swietenia spp.) y cedros (Cedrela spp.), sería deseable contar con un producto fagodisuasivo y con buena actividad sistémica, para que proteja rápidamente los tejidos jóvenes. Por tanto, conociendo que un extracto crudo del follaje de ruda (Ruta chalepensis L.) posee actividad fagodisuasiva contra dicho insecto, se formuló un producto combinando dicho extracto con varios coadyuvantes, y se evaluó en árboles de cedro amargo (Cedrela odorata L.) de 75- 100cm de altura, en un invernadero. Se utilizó un diseño completamente al azar, con 10 árboles por cada tratamiento, los que correspondieron al producto formulado, a un testigo absoluto (agua destilada), un testigo relativo (carbofurán al 1%m/v en agua) y el testigo relativo a la formulación sin el extracto crudo. Las variables medidas fueron los ataques al brote principal, el número de hojas caídas, el número de montículos y la longitud de los túneles. Para dichas variables, el producto formulado aportó excelente protección a los árboles tratados, con apenas 0.1 ataques al brote principal, en promedio, al final del período de evaluación. Asimismo, al evaluar la actividad sistémica del extracto, las sustancias presentes en él pudieron desplazarse y ser asimiladas por los árboles, causando fagodisuasión en las larvas. Finalmente, el análisis espectrofotométrico (a una longitud de onda de 355nm) permitió determinar la concentración (403±1mg/l) y el porcentaje (0.40%) del flavonoide rutina en el extracto crudo, lo cual eventualmente podría utilizarse como un compuesto marcador analítico, si llegara a desarrollarse una formulación industrial.

Actividad fagodisuasiva de las plantas Tithonia diversifolia y Montanoa hibiscifolia (Asteraceae) sobre adultos del insecto plaga Bemisia tabaci (Homoptera: Aleyrodidae)

Phagodeterrent activity of the plants Tithonia diversifolia and Montanoa hibiscifolia (Asteraceae) on adults of the pest insect Bemisia tabaci (Homoptera: Aleyrodidae). Bemisia tabaci (Gennadius) is a polyphagous, cosmopolitan and worldwide relevant pest, mainly acting as a virus vector on many crops. A sound preventive approach to deal with it would be the application of repellent or deterrent substances hopefully present in tropical plants, which in turn may contribute to take advantage of the remarkable rich Mesoamerican biodiversity. Therefore, extracts of two wild plants belonging to family Asteraceae, titonia (Tithonia diversifolia) and "tora" (Montanoa hibiscifolia), were tested for phagodeterrence to B. tabaci adults. The crude leaf extract of each one, as well as four fractions thereof (hexane, dichlorometane, ethyl acetate, and methanol) were tested under greenhouse conditions; in addition, the extracts were submitted to a phytochemical screening to determine possible metabolites causing phagodeterrence. Both restricted-choice and unrestricted-choice experiments were conducted. In the former ones, each fraction was tested at four doses (0.1, 0.5, 1.0 and 1.5% v/v), which were compared with four control treatments: distilled water, endosulfan, an agricultural oil (Aceite Agrícola 81 SC), and the emulsifier Citowett. Tomato plants were sprayed and placed inside sleeve cages, where 50 B. tabaci adults were released. The criterion to appraise phagodeterrence was the number of landed adults on plants at 48h. For the unrestricted-choice experiments, only the two highest doses (1.0 and 1.5%) of the crude extracts of each species were tested, and compared to distilled water and the agricultural oil. The titonia and "tora" crude extracts caused phagodeterrence, and for both plant species the methanol fraction stood out. Results suggest that metabolites causing phagodeterrence are several sesquiterpenic lactones, polyphenolic compounds (flavonoids and tannins) and saponins. Rev. Biol. Trop. 57 (4): 1201-1215. Epub 2009 December 01.

Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) es una plaga polífaga, cosmopolita y de gran relevancia mundial, sobre todo como vector de virus en numerosos cultivos, por lo que sería deseable un enfoque preventivo para su manejo. En tal sentido, podría recurrirse a la utilización de sustancias repelentes o disuasivas, algunas de ellas presentes en plantas tropicales, lo cual contribuiría al aprovechamiento de la rica biodiversidad mesoamericana. Por tanto, se evaluó la posible actividad fagodisuasiva sobre los adultos de B. tabaci de dos especies silvestres de la familia Asteraceae: titonia (Tithonia diversifolia (Hemsl.) A. Gray) y tora (Montanoa hibiscifolia Benth.). Para ello, en condiciones de invernadero se evaluaron los extractos crudos y cuatro fracciones (hexano, diclorometano, acetato de etilo y metanol) de ambas especies, a los cuales se les hizo un análisis fitoquímico (tamizaje) el cual permitió determinar cuáles metabolitos presentes en T. diversifolia y M. hibiscifolia podrían causar fagodisuasión en B. tabaci. Se realizaron dos tipos de experimentos: de escogencia restringida y de escogencia irrestricta. En los primeros, cada fracción se evaluó a cuatro dosis (0.1, 0.5, 1.0 y 1.5% v/v), y se comparó con cuatro tratamientos testigo: aceite agrícola, endosulfán, un emulsificante (Citowett) y un testigo absoluto (agua). Se asperjaron plantas de tomate colocadas dentro de jaulas de manga, donde se liberaron 50 adultos de B. tabaci. Para determinar si existía fagodisuasión se utilizó como criterio el número de adultos posados a las 48h. Para el experimento de escogencia irrestricta se utilizaron las dos concentraciones más altas (1.0 y 1.5%) del extracto crudo de cada especie y se compararon con el aceite agrícola y agua. Los extractos crudos de titonia y tora causaron fagodisuasión, y para ambas especies la fracción de metanol fue la que más sobresalió. En conclusión, los resultados obtenidos en los bioensayos junto con los obtenidos en el análisis de los componentes químicos presentes, sugieren que los metabolitos causantes de la fagodisuasión son algunas lactonas sesquiterpénicas, compuestos polifenólicos (flavonoides y taninos) y saponinas.

[Phagodeterrent activity of the plants Tithonia diversifolia and Montanoa hibiscifolia (Asteraceae) on adults of the pest insect Bemisia tabaci (Homoptera: Aleyrodidae)]. / Actividad fagodisuasiva de las plantas Tithonia diversifolia y Montanoa hibiscifolia (Asteraceae) sobre adultos del insecto plaga Bemisia tabaci (Homoptera: Aleyrodidae).

Bemisia tabaci (Gennadius) is a polyphagous, cosmopolitan and worldwide relevant pest, mainly acting as a virus vector on many crops. A sound preventive approach to deal with it would be the application of repellent or deterrent substances hopefully present in tropical plants, which in turn may contribute to take advantage of the remarkable rich Mesoamerican biodiversity. Therefore, extracts of two wild plants belonging to family Asteraceae, titonia (Tithonia diversifolia) and "tora" (Montanoa hibiscifolia), were tested for phagodeterrence to B. tabaci adults. The crude leaf extract of each one, as well as four fractions thereof (hexane, dichlorometane, ethyl acetate, and methanol) were tested under greenhouse conditions; in addition, the extracts were submitted to a phytochemical screening to determine possible metabolites causing phagodeterrence. Both restricted-choice and unrestricted-choice experiments were conducted. In the former ones, each fraction was tested at four doses (0.1, 0.5, 1.0 and 1.5% v/v), which were compared with four control treatments: distilled water, endosulfan, an agricultural oil (Aceite Agricola 81 SC), and the emulsifier Citowett. Tomato plants were sprayed and placed inside sleeve cages, where 50 B. tabaci adults were released. The criterion to appraise phagodeterrence was the number of landed adults on plants at 48h. For the unrestricted-choice experiments, only the two highest doses (1.0 and 1.5%) of the crude extracts of each species were tested, and compared to distilled water and the agricultural oil. The titonia and "tora" crude extracts caused phagodeterrence, and for both plant species the methanol fraction stood out. Results suggest that metabolites causing phagodeterrence are several sesquiterpenic lactones, polyphenolic compounds (flavonoids and tannins) and saponins.

Calidad del aire en dos centros hospitalarios y ocho clínicas veterinarias en Costa Rica / Air quality in two hospitals and eight veterinary clinics in Costa Rica

La calidad del aire en espacios cerrados o intradomiciliarios, es uno de los factores más importantes en la calidad de vida de los individuos puesto que pasamos del 80 a 90 por ciento de nuestro tiempo en espacios cerrados, 1. En Latinoamérica poco se ha estudiado de este tema y Costa Rica no es la excepción. No hay estudios exhaustivos sobre la calidad del aire en diferentes centros humanos, hospitales, escuelas, supermercados, oficinas, fábricas, etc., y tampoco en centros veterinarios, hospitales, clínicas, consultorios, que permitan identificar cuál es la situación sobre el tema. En este artículo evaluamos la calidad del aire en ocho clínicas y consultorios veterinarios y en dos hospitales públicos en Costa Rica. Los estudios fueron llevados a cabo en el año 2003 y 2004. Planteamos como la calidad del aire interno puede incidir en la salud de los ocupantes, tanto pacientes como de los trabajadores del lugar. Este estudio ha permitido un primer tratamiento del tema e identificación de los niveles de contaminación interna para contaminantes del aire tales como monóxido de carbono, dióxido de carbono, sistemas de ventilación, concentración de bacterias y hongos de una manera sencilla, permitiendo con el conocimiento de la situación ofrecer medidas correctivas a los problemas detectados. Se encontró que en general la contaminación microbiana del ambiente es aceptable, no así para material particulado, estos datos se dan tanto en los centros hospitalarios humanos como en los centros veterinarios. En ambos sitios, centros hospitalarios como clínicas veterinarias, las prácticas ocupacionales por lo general provocan un aumento en la concentración de vectores contaminantes.

Given that 80% to 90% of our time is spent indoors (1), air quality in closed or intradomiciliar spaces is one of the most important factors in our quality of life. In Latin America, this topic has not been very well studied and Costa Rica is not the exception. Thus, there are nopublications which allow the study of indoor air quality in different either human (hospitals, schools, supermarkets, offices, factories and the like) or veterinary centers (hospitals, clinics, offices). In this article we evaluate indoor air quality in eight veterinary clinics and in two public hospitals in Costa Rica; these studies were carried out in 2003 and 2004. We postulate a mechanism wherebyindoor air quality can affect the health of the dwellers of these spaces, be they patients or workers. This study has allowed an initial discussion of thistopic and identified internal contamination levels for substances such as carbon monoxide, carbon dioxide, ventilation systems and bacterial as wells as fungalconcentrations. Hopefully, this knowledge will permit corrective measures to be offered to the problemsdetected. It was found that, in general, microbial contamination of the environment is acceptable exceptfor particulate material. Data are offered for both human hospitals as well as veterinary centers. In general, in both sites, occupational practices cause an increase in the concentration of contaminating vectors.