ABSTRACT Perennial ryegrass is one of the most important food sources in animal production. However, several pests affect this crop, and one of the primary control strategies is the symbiotic relationships between ryegrass endophyte fungi. This fungus produces alkaloids that exhibit toxic activity against arthropods. Furthermore, the effect of fungi may extend to higher trophic levels, including predators (spiders and/or insects), decreasing their abundance and diversity. Given the importance of spiders and insects as predators, whether the symbiotic interaction between perennial ryegrass and endophyte fungus reduces the abundance and diversity of predators pose an important question. To address this question, natural enemies in perennial ryegrass were collected and analyzed over a year, and the percentage of endophyte fungus was evaluated by the presence of hyphae from two ryegrass cultivars, Jumbo (E-) and Alto AR1 (E+). We observed an 80% endophyte infection rate for (E+) and 0% for (E-). Moreover, 222 individual spiders corresponding to 10 families were identified in both perennial ryegrasses, including 209 individuals for (E-) and 13 for (E+). The most abundant spider family was Lycosidae, representing 71.17% of the total spiders. In addition, 65 insects were collected, corresponding to 6 families, with Carabidae being the most abundant. Furthermore, the Simpson index indicated the dominance of the family Lycosidae. Overall, spider and insect abundance and diversity were reduced in (E+), suggesting a negative effect of the endophyte on predator populations.

Abstract Flavonoid biosynthesis may be affected by plant domestication, with flavonoid production being reduced in proportion to the degree of domestication. In this context, kaempferol (3,4´,5,7-tetrahydroxyflavone) has been identified in the leaves of wild and cultivated Ugni molinae, a berry endemic to Chile. The biosynthetic pathway of kaempferol production begins with naringenin (4´,5,7-trihydroxyflavanone), which is converted to dihydrokaempferol (3,4´,5,7-tetrahydroxyflavanone), catalyzed by flavanone 3ß-hydroxylase (FHT) and then converted to kaempferol by a bifunctional enzyme called flavonol synthase (FLS). Therefore, our study aims to evaluate how FLS activity is affected in murtilla plants that are subjected to the domestication process. Kaempferol was quantified from methanolic extracts of leaf samples collected from both cultivated and wild U. molinae plants using high-performance liquid chromatography, and enzyme extraction was performed to determine FLS activity. The results showed that kaempferol concentration in wild plants from the Soloyo (0.14 μg g-1), Mehuín (0.18 μg g-1) and Queule (0.25 μg g-1) sampling areas was higher than in their cultivated counterparts. Our data are consistent with the FLS activity detected in samples obtained from Manzanal Alto (134.79 pKatal, Soloyo (96.48 pKatal), and Mehuín (119.97 pKatal). These samples also exhibited higher enzymatic activity than their cultivated counterparts. Together, these data suggest that FLS activity is negatively affected by the domestication process.

Resumen La biosíntesis de flavonoides puede verse afectada por la domesticación vegetal, reduciéndose la producción en relación al grado de domesticación. En este contexto, ha sido identificado el kaempferol (3,4´, 5,7-tetrahidroxiflavona) en hojas de Ugni molinae silvestre y cultivada. La ruta biosintética del kaempferol comienza con naringenina (4´, 5,7-trihidroxiflavanona), que se convierte en dihidrokaempferol (3,4´, 5,7-tetrahidroxiflavanona), catalizada por la flavanona ٣ß-hidroxilasa (FHT). Finalmente, se convierte en kaempferol por una enzima bifuncional llamada flavonol sintasa (FLS). Por lo tanto, nuestro estudio tiene como objetivo evaluar cómo se ve afectada la actividad de FLS en plantas de murtilla que están sujetas a un proceso de domesticación. El kaempferol fue cuantificado a partir de los extractos metanólicos de hojas recogidas en plantas cultivadas y silvestres de U. molinae mediante cromatografía líquida de alta resolución. Además, se realizó una extracción de enzimas para determinar la actividad de FLS. Los resultados mostraron que la concentración de kaempferol en las áreas de muestreo silvestre de Soloyo (0.14 μg g-1), Mehuín (0.18 μg g-1) y Queule (0.25 μg g-1) fue mayor que en sus contrapartes cultivadas. Estos datos fueron consistentes con la actividad de FLS determinada en muestras obtenidas de Manzanal Alto (134,79 pKatal), Soloyo (96,48 pKatal) y Mehuín (119,97 pKatal). Estos también exhibieron una mayor actividad enzimática que sus contrapartes cultivadas. Por lo tanto, nuestros datos sugieren que la actividad de FLS se ve reducida por la domesticación vegetal.

Abstract: In laboratory by dual choice test, stem and root alkaloid extracts of Berberis microphylla showed antifeedant activity against third-instar Plutella xylostella larvae. Stem extracts showed significantly lower leaf consumptions at concentrations of 500 and 1000 mg/L, as illustrated by antifeedant index of 72 and 97% respectively, whereas, root extracts were significantly active at 100, 500 and 1000 mg/L with antifeedant index of 68, 85 and 99% respectively. In addition, the pure berberine identified as the major alkaloid in the plant extracts showed significant lower food consumption by larvae only at concentration of 1000 mg/L, but the pure palmatine not affect feeding at any concentration. The results suggest that alkaloids extract of B. microphylla have promising antifeedant activity and could by incorporated in an integrated pest management (IPM) programs for P. xylostella.

Resumen: En laboratorio, mediante prueba de doble elección los extractos de alcaloides obtenidos de tallos y raíces de Berberis microphylla mostraron actividad antialimentaria frente a larvas de tercer estadio de Plutella xylostella. Los extractos de tallos mostraron consumos foliares significativamente más bajos en concentraciones de 500 y 1000 mg/L con un índice antialimentario de 72 y 97% respectivamente, mientras que los extractos de raíces fueron significativamente más activos a 100, 500 y 1000 mg/L con un índice antialimentario de 68, 85 y 99% respectivamente. Además, berberina identificada como el principal alcaloide de los extractos tuvo significativamente un menor consumo de alimento por parte de las larvas mostrando su efecto solo a la concentración de 1000 mg/L. Por otra parte, palmatina no tuvo efecto en la conducta de alimentación de las larvas a ninguna de las concentración evaluadas. Los resultados sugieren que los extractos de alcaloides obtenidos de B. microphylla tienen una prometedora actividad antialimentaria y podrían ser incorporados en un programa de manejo integrado de plagas (MIP) para P. xylostella.

ABSTRACT Acetylcholinesterase is an important target for control of neurodegenerative diseases causing cholinergic signaling deficit. Traditionally, galanthamine has been used as an Amaryllidaceae-derived acetylcholinesterase inhibitor, although new Amaryllidaceae plants could serve as source for better acetylcholinesterase inhibitors. Therefore, the objective of this study was to characterize the alkaloid composition from bulbs of Rhodolirium andicola (Poepp.) Traub, a native Chilean Amaryllidaceae specie, and assess their inhibitory activity on acetylcholinesterase by in vitro and in silico methodologies. Alkaloidal extracts from R. andicola exhibited an inhibitory activity with IC50 values between 11.25 ± 0.04 and 57.78 ± 1.92 µg/ml that included isolated alkaloid, galanthamine (2.3 ± 0.18 µg/ml), Additionally, 12 alkaloids were detected using gas chromatography–mass spectrometry and identified by comparing their mass fragmentation patterns with literature and database NIST vs.2.0. To better understand the bioactivity of isolated compounds and alkaloidal extracts against acetylcholinesterase, a molecular docking approach was performed. Results suggested that alkaloids such as lycoramine, norpluvine diacetate and 6α-deoxy-tazettine expand the list of potential acetylcholinesterase inhibitors to not only galanthamine. The role of R. andicola as a source for acetylcholinesterase inhibitors is further discussed in this study.

In the last decade, there has been increasing interest in investigating the impact of flavonoids on insects, specifically for pest control. In this study, we investigated the impact of isoflavonoids upon the feeding behavior of the clover root borer, Hylastinus obscurus Marsham (Coleoptera: Curculionidae), which is one of the most serious global pests associated with red clover, Trifolium pratense L. Four aglycones isoflavonoids: genistein (1), formononetin (2), daidzein (3) and biochanin A (4) were isolated and identified by HPLC, from roots of two Chilean red clover cultivars. The first two compounds, formononetin (2) and genistein (), showed high feeding deterrent activity when they were evaluated in artificial diets. This antifeedant effect of isoflavones on feeding behavior of H. obscurus suggests that they are responsible for a decreasedin insect weight gain as compared with the control. This information could be useful respectively, to farmers and researcher to produce and create plants resistant to curculionid.

The Argentine stem weevil, Listronotus bonariensis, is an important pest in pastures, especially ryegrass (Lolium sp.), compromising grassland persistence and productivity. Both, adult and specially larvae cause severe damage, action that generate the death of the tiller and reducing forage production. Chemical control has limited effectiveness in adult’s insect and negative effects on the environmental and toxicity to pollinators when applied close to the flowering period is observed. Therefore, the main currently strategy is based on the use of cultivars of Lolium endophyte fungus-infected with Neothypodium genus. However, over a decade that there are no reports on the presence of this weevil in southern Chile. Hence, the aim of this research was report the actual incidence of L. bonariensis in ryegrass pastures. The results of two years of prospecting showed that this weevil is currently causing damage to the ryegrass pastures indicating that the effectiveness of species infected with the fungus must be evaluated.

ABSTRACT Previous researches have established that the swim speed of some microcrustaceans is influenced by chemical compounds emitted by conspecifics. We examined the hypothesis that cuticular compounds present on the body surface of A. franciscana, the most widespread member of Artemia genus, play a role in the swim speed of conspecific males. The movements (swim) of one male confronted to a sponge soaked with female or male cuticular extract, were recorded during 30 minutes and the swim speed was determined using a behavioral tracking software (Ethovision 3.1, Noldus Technologies). As a control, the movements of one male confronted to a sponge soaked with salty water or with a mixture of the solvents used in the extraction (chloroform-methanol), was recorded. The results showed that cuticular compounds from either female or male increase 1.5 (ca.) times the swim speed of males in comparison with the controls treatments salty water and the solvents. There was no a significant difference between the controls (salty water and chloroform-methanol). Chemical characterization was developed by sterification of the cuticular extracts and analyses by GC-FID and GC-MS. Four saturated fatty acid (myristic acid, palmitic acid, estearic acid, arachidic acid) and five insaturated fatty acids (oleic acid, linoleic acid, linoleic acid 3n3, cis-11-eicosanoic acid, euric acid) were identified. Myristic acid was found in female cuticular extract, but not in male cuticular extract. Results suggest that chemical compounds present in the cuticular surface of A. franciscana females could have an important role in the intra-specific recognition in this specie.

RESUMEN Investigaciones anteriores han establecido que la velocidad de nado de algunos microcrustáceos se encuentra influenciada por compuestos químicos emitidos por conespecíficos. Nosotros examinamos la hipótesis de que los compuestos cuticulares presentes sobre la superficie corporal de A. franciscana, el miembro con mayor distribución mundial del genero Artemia, juega un rol en la velocidad de nado de machos conespecíficos. Los movimientos nado de un macho confrontado a una esponja empapada con extracto cuticular de una hembra o de un macho, fueron grabados durante 30 minutos y la velocidad de nado fue determinada usando un software de rastreo conductual (Ethovision 3.1, Noldus Technologies). Como control, fueron grabados los movimientos de un macho confrontado a una esponja empapada con agua de mar artificial o con una mezcla de los solventes usados en la extracción (cloroformo-metanol). Los resultados mostraron que los compuestos cuticulares tanto de hembras como de machos incrementan 1,5 veces (aproximadamente) la velocidad de nado de los machos, en comparación con los experimentos control donde se uso agua de mar artificial y los solventes de la extracción. No hubo diferencias significativas entre los controles (agua de mar artificial y cloroformo-metanol). La caracterización química fue desarrollada mediante esterificación de los extractos cuticulares y analizados por CG-DIL y CG-EM. Cuatro ácidos grasos saturados (ácido mirístico, ácido palmítico, ácido esteárico, ácido araquídico) y cinco ácidos grasos insaturados (ácido oleico, ácido linoleico, ácido linoleico 3n3, ácido cis-11-eicosanoico, ácido eurico) fueron identificados. El ácido mirístico fue encontrado en los extractos cuticulares de hembras pero no en los extractos cuticulares de machos. Los resultados sugieren que los compuestos químicos presentes en la superficie cuticular de las hembras de A. franciscana podrían tener un importante rol en el reconocimiento intraespecífico de la especie.

Plant domestication is a process in which plants’ chemical defenses that help them cope with herbivores might decline. Consequences of this process could be reflected in an increase in insect pests. Therefore, we carried out a survey to contrast the diversity, damage indexes and insect assemblages between cultivated and wild "Murtilla" (Ugni molinae) plants. The main scientific question put forward in this paper is as follows: Is there a decrease in diversity and an increase in both insect assemblages and damage indexes associated with the domestication process in U. molinae plants? The objective of this report was to compare the structure of a taxonomic assemblage collected in both wild and cultivated plants and their temporal variation over the year. Seven ecotypes and their respective wild populations were selected for these studies. The results showed higher insect assemblages in wild parents (77.35%) vs. cultivated (22.7%). The damage indexes were also higher in wild plants (0.23). The diversity indexes according to Margalef (12.98), the Shannon index (5.15) and the Simpson index (19.04) were higher in wild plants. Moreover, approximately 60 species were determínate. We detected changes in insect assemblages, damage and diversity indexes that could suggest that murtilla domestication has altered insect assemblages.

M. Chacón-Fuentes, M. Lizama, L. Parra, I Seguel y A. Quiroz. 2016. Diversidad, composición de la comunidad de insectos e índice de daño, en murtillas silvestres y cultivadas. Cien. Inv. Agr. 43(1):57-67. La domesticación vegetal es un proceso en el cual las plantas pueden disminuir su nivel de defensas químicas para combatir herbívoros. Algunas de las posibles consecuencias podrían reflejarse en un incremento en el número y en la diversidad de insectos. Por lo tanto, se realizó un "survey" para comparar el índice de daño y la diversidad de insectos en plantas cultivadas y silvestres de murtilla (Ugni molinae). La principal interrogante de este trabajo fue: ¿La domesticación en plantas de murtilla, disminuirá la diversidad e incrementará el índice de daño y la comunidad de insectos? El objetivo de esta investigación fue comparar la población de insectos asociada a plantas silvestres y cultivadas además de analizar su variación durante el año. Siete ecotipos y sus correspondientes contrapartes silvestres fueron seleccionadas para este estudio. Los resultados mostraron un mayor número de insectos en plantas silvestres (77,35%) vs. (22,7%) cultivadas. El índice de daño fue mayor en plantas silvestres (0,23) comparada con plantas cultivadas. El índice de Margalef mostró la mayor riqueza de insectos en plantas cultivadas. Sin embargo, el índice de Shannon fue mayor (5.15) en plantas silvestres. Además, cerca de 60 especies de insectos fueron determinadas. Se detectaron cambios en la comunidad de insectos, índices de daño y diversidad que podrían sugerir que la domesticación en murtilla ha alterado la comunidad de insectos.

Introducción: el tejido adiposo humano está compuesto por diferentes tipos celulares, y ha sido objeto de múltiples estudios en los últimos años debido a su acción en diversas funciones. Métodos: se realizó una búsqueda bilbiográfica en PubMed, Scielo, Science Direct and Google Scholars y se reporta la experiencia de los autores. Resultados: los primeros modelos de estudio fueron con tejido de roedores, y permitieron la comprensión del metabolismo de carbohidratos y ácidos grasos y facilitaron el estudio de la biología del adipocito, junto a estudios histológicos y el aislamiento de adipocitos maduros. Posteriormente se realizaron estudios con células precursoras (preadipocitos) que propiciaron el aislamiento de la línea celular 3T3-1L murina. En Latinoamérica, se han realizado diversos estudios con líneas celulares y con células madre mesenquimales precursoras de adipocitos para estudiar el efecto de hormonas y otras sustancias y para genotipificación. En Colombia se han realizado estudios con adipocitos 3T3-L1 para determinar los efectos de medicamentos y sustancias en estas células. En el laboratorio de Fisiología Celular de la Universidad Tecnológica de Pereira el proceso de obtención de muestras ha evidenciado dificultades por tratarse de tejido humano, pero el protocolo de aislamiento y cultivo pudo ser estandarizado a lo largo de seis años de experimentación; se aislaron preadipocitos y adipocitos maduros que permitieron estudiar los efectos de hormonas, realizar caracterización electrofisiológica y estudiar la fisiología del calcio. Conclusiones: este es un campo de investigación muy relevante debido a la implicación de este tipo celular en funciones metabólicas sistémicas y su relación con patologías de alta prevalencia como la obesidad y el síndrome metabólico.

Introduction: The human adipose tissue is composed of different cell types. It has been subject of several studies in the past years due to its role on diverse functions. Methods: A search in the PubMed, Scielo, Science direct and Google Scholars databases was performed and the authors experience was reported. Results: The first model used was rodent fat, which allowed a better comprehension on carbohydrate and fatty acid metabolism and enhanced research in adipocyte cell biology in addition with histological studies and mature adipocyte isolation. Afterwards, learning about precursor cell (pre-adipocytes) promoted the isolation of murine 3T3-L1 cell line. In Latin America research has been conducted using cell lines and adipocyte precursor mesenchymal stem cells to describe effects of hormones and perform DNA sequencing. In Colombia, studies in 3T3-L1 cell line aimed to stablish the effects of different compounds on these cells. In the Cell Physiology Laboratory of the Universidad Tecnológica de Pereira, sample collection process has shown difficulties because the source was human tissue; nevertheless isolation and cell culture protocols were standardized throughout the last six years of experimentation. Pre-adipocytes and mature adipocytes were isolated to study the effects of hormones, perform electrophysiological characterization and study calcium physiology. Conclusions: This is a relevant research field since these cells have important systemic metabolic functions and they have a clear relationship with high-prevalence pathologies such as obesity and the metabolic syndrome.

Two behavioral experiments were performed to test that A. franciscana shows specific courtship patterns, which in part, would be governed by semiochemicals released by females. The courtship ethogram, based on 30 adult virgin pairs (1 female v/s 1 male) individually video recorded for 1 hour, revealed that males display four independent activity patterns: 1) approach and touch, 2) swim behind, 3) riding attempt, and 4) riding success. The analysis of the transitions among the observed patterns suggested two ways to achieve riding success, both requiring female touch. In one, males approach and touch females followed by riding attempt (27% probability of occurrence), but if the latter fails, males start over from approach and touch (23% probability of occurrence) to finally achieve riding success (19% probability of occurrence). The alternative route is approach and touch, swimming behind (7% probability of occurrence) and riding success (5% probability of occurrence). The role of semiochemicals released from females was assessed by using the polar solution (PS) extracted from water conditioned with 40 adult virgin females. Virgin males were soaked with PS for obtaining pseudo females. Afterwards, we confronted 1 pseudo female, 1 female, or 1 control male to either 1 male or 5 male. In all cases the behavior was recorded for 1 hour (N=10), and the frequencies of occurrence of each courtship patterns were analyzed. The most important results showed that: 1) virgin female and pseudo female elicited the same frequency of response in 1 male in all four courtship patterns (P˃0.05); b) virgin female and pseudo female elicited the same response when tested against 5 males in approach and touch, swim behind and riding attempt (P˃0.05). The fact that in all the cases control male always elicited the lowest frequency value in each courtship patterns, strongly suggests the possible role of sexual semiochemicals in the courtship behavior of A. franciscana. The combination of behavior and chemical cues suggests an elaborate pre-mating recognition.

Se realizaron dos experimentos conductuales para evaluar que A. franciscana muestra patrones de cortejo específicos, que en parte, serían gobernados por semioquímicos liberados por hembras. El etograma del cortejo, construido a partir de la grabación individual de 30 parejas adultas vírgenes (1 hembra v/s 1 macho) durante 1 hora, reveló que los machos mostraron cuatro patrones de actividad independientes: 1) acercamiento y toque, 2) nado en retroceso, 3) intento de monta, y 4) éxito de monta. El análisis de las transiciones entre los patrones observados sugirió dos maneras de conseguir una monta exitosa, en ambas el patrón acercamiento y toque fue fundamental. La primera transición consistió en que una vez que los machos se acercan y tocan a las hembras, intentan montar a las hembras (27% de probabilidad de ocurrencia), pero si esto no ocurre los machos comienzan nuevamente a acercarse y tocar a las hembra (23% de probabilidad de ocurrencia) para finalmente lograr una monta exitosa (19% de probabilidad de ocurrencia). La ruta alternativa es mediante la aproximación y toque para luego desarrollar el nado en retroceso (7% de probabilidad de ocurrencia) y montaje exitoso (5% de probabilidad de ocurrencia). El rol de los semioquímicos liberados por hembras fue evaluado mediante el uso de la solución polar (SP) obtenida desde agua acondicionada con 40 hembras vírgenes. Machos vírgenes fueron empapados con SP para obtener pseudo hembras. Luego, se enfrentaron 1 pseudo hembra, 1 hembra, 1 macho control a ya sea 1 o 5 machos. En todos los casos, la conducta fue registrada durante 1 hora (n=10), y se analizaron las frecuencia de ocurrencia de cada uno de los patrones de cortejo. Los resultados más importantes mostraron que: 1) la hembra virgen y pseudo hembra elicitó la misma frecuencia de respuesta en 1 macho en los cuatro patrones de cortejo (P˃0,05); b) hembras vírgenes y pseudo hembras obtuvieron la misma respuesta cuando se evaluaron contra 5 machos en acercamiento y toque, nado en retroceso e intento de monta (P˃0,05). El hecho que en todo los casos el macho control siempre elicitó el menor valor de frecuencia en cada patrón de cortejo sugiere el posible rol de semioquímicos sexuales en la conducta de cortejo de A. franciscana. La combinación de señales químicas y conductuales sugieren un elaborado reconocimiento de pre-cortejo.

The contents of long-chain fatty acids in non-polar root extracts from 1.6 year-old red clover plants of two cultivars (Superqueli INIA and Quiñequeli INIA) and one experimental line (Syn II Pre III), their relationships with H. obscurus populations, and the stimulant or deterrent effects of the root extracts and of individual fatty acids on the weight gain of H. obscurus were investigated. There was an inverse relationship between the insect population size and the palmitic acid content. The Superqueli INIA cultivar contained the highest palmitic acid content and the lowest insect load. When solutions of either palmitic or oleic acids were individually incorporated into an artificial diet, palmitic acid caused a decrease in weight gain, whereas the effect of oleic acid was similar to that of the phagostimulant saccharose. Hence, palmitic acid might be applied directly in H. obscurus control programs to prevent or reduce feeding and oviposition behaviors or might be used as a tool for selecting resistant cultivars.

El contenido de ácidos grasos de cadena larga en extractos apolares de raíces de trébol rosado de 1,6 años de edad provenientes de dos cultivares (Superqueli INIA y Quiñequeli INIA) y una línea experimental (Syn II Pre III), su relación con poblaciones de H. obscurus, y el efecto estimulante o disuasivo de extractos de raíces y ácidos grasos individuales sobre la conducta de alimentación de H. obscurus fueron investigados. Se determinó una relación inversa en el cultivar Superqueli INIA entre la población de insectos y el contenido de ácido palmítico. Cuando soluciones de ácido palmítico y oleíco fueron incorporadas individualmente en una dieta artificial, solo el ácido palmítico mostró un efecto disuasivo en la alimentación, mientras que el ácido oleico mostro un efecto similar al fagoestimulante sacarosa (control positivo). Por lo tanto, el ácido palmítico podría ser utilizado en programas de control de H. obscurus aplicado directamente para prevenir o reducir la conducta de alimentación y oviposición, o convertirse en una herramienta para la selección de cultivares resistentes a este insecto.

Background Enteric red mouth disease and Saprolegniasis, which are caused by the bacteria Yersinia ruckeri and the oomycete Saprolegnia parasitica, respectively, are important illnesses that affect salmonid farming. Sanitary problems in farms are addressed by the prevention of disease outbreaks or by the treatment of diseases with chemicals. Environmental and governmental restrictions, toxicity and high treatment costs limit the use of drugs. Marine organisms, such as algae, sponges and corals, have developed an antimicrobial defense strategy based on the production of bioactive metabolites. Among these organisms, seaweeds offer a particularly rich source of potential new drugs. Hence, many pharmacologically active substances have been isolated from seaweeds. In the Ceramium genus, Ceramium rubrum has been emphasized by several authors for its antimicrobial properties. Based on this background, the present study focused on the antimicrobial activity of a lipophilic extract of C. rubrum on Y. ruckeri and S. parasitica. Results The alga, collected from the Pacific coast of Chile, underwent an ethanol extraction, and the concentrated extract was partitioned between water and dichloromethane. From the dichloromethane extract, fatty acids, fatty acid esters, one hydrocarbon and phytol were identified by Gas Chromatography-Mass Spectrometry (GC/MS) analysis. The antimicrobial study showed that the whole extract was more active than the individual components, which suggests a strong synergistic effect among the components. Conclusions These results may constitute a basis for promising future applied research that could investigate the use of C. rubrum seaweed as a source of antimicrobial compounds against fish pathogens.

Se realizó el estudio morfológico e histológico del sistema digestivo de Aegorhinus superciliosus (Coleoptera: Curculionidae), plaga de importancia económica en el sur de Chile. Esta especie presenta un sistema digestivo característico para la mayoría de los insectos, siendo similar en machos y hembras, pero de mayor longitud en las últimas, llegando a medir el doble del tamaño del insecto. El sistema digestivo es un tubo largo de diámetro variable, dividido en tres regiones: intestino anterior (estomodeo), intestino medio (mesenterón) e intestino posterior (proctodeo). Histológicamente presenta un tejido epitelial similar al descrito para otras especies y externamente un tejido muscular, sin diferencias entre machos y hembras. No obstante, presenta características que difieren en otros curculiónidos y coleópteros tales como: ausencia de buche, ubicación y número de los ciegos gástricos, presencia de membrana peritrófica y ausencia de almohadillas rectales.

A morphological and histological study was performed on the digestive system of Aegorhinus superciliosus (Coleoptera: Curculionidae), an important economic pest in southern Chile. This species has a typical digestive system for most insects, being similar in males and females, but longer in the latter, being twice the length of the insect. The digestive system is a long tube of variable diameter, divided into three regions: foregut, midgut and hindgut. From the histological point of view, it presents epithelium tissue features similar to the one described for other species, and externally it has a muscle tissue with no differences between males and females. Nevertheless, it shows features which differ either in other weevils or in beetles such as: absence of crop, the location and number of gastric caeca, presence of peritrophic membrane, and absence of a rectal pad.

L. Parra, A. Mutis, F. Ortega, and A. Quiroz. 2013. Field response of Hylastinus obscurus Marsham (Coleoptera: Curculionidae) to ,E-2-hexenal and limonene, two host-derived semiochemicals. Cien. Inv. Agr. 40(3): 637-642. Red clover (Trifolium pratense L.), a valuable legume in Chile, is important mainly for seed production and as forage for animal production. Although it is considered a perennial, the productivity of this legume declines during the second year of growth primarily because of infestation by the red clover root borer, Hylastinus obscurus (Coleoptera: Curculionidae). Currently, there is no efficient method for controlling this insect, although the use of semiochemicals may provide a new alternative to reduce the damage caused by this curculionid. In this context, E-2-hexenal and limonene, which were previously determined to be an attractant and a repellent, respectively, for H. obscurus, were released from dispensers established in two cultivars (Quiñequeli INIA and Superqueli INIA) and one experimental line (Syn II Pre III) of red clover at the Centro Regional de Investigación Carillanca (INIA-Carillanca) (Vilcún, Chile). H. obscurus was found in significantly higher numbers on plants from areas treated with E-2-hexenal than from areas treated with limonene or in areas that were left untreated as control areas. However, this attractiveness was influenced by the red clover source such that the effect of E-2-hexenal was observed in Superqueli INIA and Syn II Pre III but not in Quiñequeli INIA. Unlike previous studies, limonene had no effect on H. obscurus. Our results provide the first evidence under field conditions for the potential use of E-2-hexenal as an attractant for the red clover root borer H. obscurus.

L. Parra, A. Mutis, F. Ortega y A. Quiroz. 2013. Respuesta de Hylastinus obscurus Marsham (Coleoptera: Curculionidae) a ,E-2-hexenal y limoneno, dos semioquímicos derivados de su hospedero, en condiciones de campo. Cien. Inv. Agr. 40(3): 637-642. El trébol rosado es una valiosa leguminosa, cuya importancia en Chile radica principalmente en la producción de semillas y su uso como alimento forrajero. A pesar de ser una planta perenne, su producción declina durante el segundo año de establecida, debido principalmente a la infestación del barrenador de la raíz del trébol Hylastinus obscurus (Coleoptera: Curculionidae). Actualmente no existe un método de control eficiente contra este insecto, por lo tanto, el uso de semioquímicos surge como una nueva alternativa para disminuir los daños ocasionados por este curculiónido. En este contexto, E-2-hexenal y limoneno, determinados previamente como atrayente y repelente a H. obscurus, fueron dispuestos en dispensadores de liberación lenta establecidas en dos cultivares y una línea experimental de trébol rosado en Centro de Investigación INIA Carillanca (Vilcún, Chile). Las evaluaciones indican que H. obscurus fue significativamente encontrado en mayor proporción en plantas sometidas al tratamiento con E-2-hexenal, comparadas con limoneno y el control. Sin embargo, este efecto atrayente fue influenciado por los cultivares y línea experimental de trébol rosado, de tal manera que el efecto de E-2-hexenal fue observado en Superqueli INIA y Syn II Pre III, pero no en Quiñequeli INIA. En contraste a previos estudios, limoneno no tuvo efecto sobre H. obscurus. Nuestros resultados permiten establecer la primera evidencia bajo condiciones de campo del potencial uso, especialmente E-2-hexenal, como un atrayente para H. obscurus.

Background: The horn fly, Haematobia irritans, is an obligate bloodsucking ectoparasite of pastured cattle and is a major pest of livestock production in North and South America and Europe. In this study, we investigated the potential to use cattle pastures, infected with non-toxic, "friendly" fungal-endophyte-infected (E+) tall fescue, Festuca arundinacea Schreb., as a strategy for reducing horn fly loads in cattle, and to evaluate the possible bioinsecticide effect on horn fly larvae. Results: When cattle grazed in E+ tall fescue, a decrease in fly-load was observed, compared with other pastures (endophyte-free (E-) pastures). The infestation of horn fly load decreased according to an increase in the percentage of endophyte present in the different pastures (0 to 100%). Moreover, two groups of animals with significant differences in the fly-load (high and low fly-load) in the same herd were observed (P < 0.05). Additionally, it was possible to determine a bioinsecticide effect of cattle dung, upon horn fly larvae (80%), from animals fed E+ tall fescue. Conclusions: These results constitute the first report on the potential for exploiting pasture management for controlling 1) horn fly-loads on cattle and 2) the normal development of horn fly larvae. In conclusion, this information provides preliminary understanding of the role of cattle pasture diet management for controlling horn fliesas part of an integrated pest management strategy for this major pest of farmed livestock.