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Cotton is one of the most widely used industrial products in various industries and is attacked every year by the cotton bollworms, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). In this study, we investigated the effect of the spinosad insecticide on some biological and bio chemical parameters of the cotton bollworm. Bioassays were performed by using 3rd instar larvae fed with artificial diets containing lethal (LC50), and sublethal (LC15) concentrations of spinosad. Lethal and sublethal concentrations were estimated to be 0.90 and 0.35, mg a.i./kg, respectively. Compared to the control, lethal and sublethal concentrations of spinosad significantly increased larval and pupal development time, decreasing their weight. In addition, only LC50 of spinosad significantly reduced the fecundity and lifespan of adults as well as the hatching rate of the pest compared to LC15 and control. Moreover, lethal and sublethal concentrations of spinosad reduced carbohydrate and glycogen content and did not change lipid content. A significant decrease in protein content was observed only after exposure to LC50. At LC50 the activities of glutathione S-tran sferase (GSTs), a- an d ß- esterase were significantly reduced compared to LC15 and control. The results of this study showed that LC50 and LC15 of spinosad affect several biochemical and biological parameters of H. armigera. Therefore, spinosad at the lethal and sublethal concentrations can be included in integrated pest management (IPM) for this pest. [ABSTRACT FROM AUTHOR]

Copyright of Caldasia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Biológico Agropecuaria Tuxpan is the property of Revista Biologico Agropecuaria Tuxpan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of ESPOCH Congresses: The Ecuadorian Journal of S.T.E.A.M. is the property of Knowledge E DMCC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ants are very diverse hymenopterans with a wide geographical distribution. They are social insects and their communication is based on chemical signals. Within the group of semiochemicals that regulate the search for foods are the trail pheromones on the roads. The purpose of this review is to document the main tracking pheromones on the trails that guide ants to feeding sources. A systematic review was carried out based on the guidelines of the PRISMA statement of research found in PubMed, Web of Science and Google Scholar of the pheromones trails. Reported 26 chemical compounds were reported in 14 species of ants, the main sources of obtaining were extracts of the whole body, abdomen and glands. The detection of the semiochemicals were electrophysiological responses of Hymenoptera and chromatographic methods, recording short and long-chain organic compounds (C05-C18). The study of trial chemical compounds has been carried out on a small number of species, this type of research has great potential for the control of invasive ants, since their distribution has had negative repercussions on ecosystems and economic damage to man. [ABSTRACT FROM AUTHOR]

The insecticidal and repellent activities of methanolic extracts of Ruta chalepensis L. (Rutaceae: Sapindales), Rhazya stricta Decne (Apocynaceae: Gentianales), Heliotropium bacciferum Forssk (Boraginales: Boraginaceae), Salvadora pérsica L. (Salvadoraceae: Brassicales), and Moringa oleífera L. (Moringaceae: Brassicales) were investigated against the saw-toothed grain beetle Oryzaephilus surinamensis L. (Coleóptera: Silvanidae). Results demonstrated that all these plant extracts had variable toxicity against the beetle. The effectiveness of the tested plant extracts was shown by increasing the used concentrations. The methanolic extract from R. stricta performed the best and was able to cause 93.3% and 89.2% mortality for the adult and larval stage of O. surinamensis, respectively, at 500 ppm after six days of plant extract treatment. The tested extract of S. pérsica at 500 ppm caused 80.8% and 82.5% mortality on larvae and adults of O. surinamensis after six-day of treatment. On the other hand, repellent effects of extracts of R. stricta, S. pérsica, and R. chalepensis at 500 ppm were recorded, with higher values of 91.7%, 83.3%, and 78%, respectively, against the adults of O. surinamensis, which were under 500 ppm. These extracts especially from R. stricta, S, spinosa, and R. chalepensis could be useful to prevent damages and store grain production losses for O, surinamensis. [ABSTRACT FROM AUTHOR]

Microalgae are unicellular photosynthetic microorganisms that can grow autotrophically or heterotrophically. They are considered a source of biomolecules and metabolites of nutritional, pharmaceutical and industrial importance since they can be used for the production of biofuels, biofertilizers, food for consumption and wastewater treatment. In the present work, the cultivation potential of four native microalgae from the department of Bolívar from different bodies of water was evaluated. After their isolation and identification, the microalgae were cultivated following the Batch-type scaling system and once the exponential phase was reached, 100 mL of each species was inoculated in triplicate, measuring up to 1 liter. The bioassays were carried out using the modified Conway culture medium and under controlled conditions of temperature, aeration, light intensity and photoperiod. Cell growth and kinetic parameters were determined by cell quantification using a Neubauer chamber. In addition, a Kruskal-Wallis statistical analysis and the post-hoc multiple range test were performed.It was found that Dunaliella salina reached the highest cell density (12,957,500 cell/mL) compared to Cyclotella meneghiniana (225,000 cell/mL), Nitzschia palea (367,500 cell/mL) and Navicula tripunctata (1,107,500 cell/mL). In the exponential phase, N. palea presented the highest growth rate, the highest divisions per day and the shortest generation time. On the contrary, D. salina presented a lower growth rate, lower divisions per day and longer generation time. Statistical tests indicated significant differences between the cultures and the multiple range a posteriori test showed that D. salina was the species with different population growth, making it suitable for mass cultivation for commercial purposes to obtain bioproducts [ABSTRACT FROM AUTHOR]

Copyright of Revista de Toxicología is the property of Asociacion Espanola de Toxicologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: the bioassay with the bioindicator species Daphnia magna Strauss, 1820 makes it possible to obtain the individual acute ecotoxicological effect and in a mixture of various chemical toxics by means of the mean lethal concentration (LC50). Objective: to determine the ecotoxicological effect of the mixture of aroclor 1254 and lead (Pb2+) on D. magna. Materials and Methods: LC50 was measured with arochlor 1254> Pb2+, and subsequently the concentration without ecological effect (PNEC) for the individual effect and as a mixture. PNEC values were contrasted with category 4-E1 (lagoons and lakes) and E2 (rivers) of the Peruvian Environmental Quality Standard (Supreme Decree No. 004 2017-MINAM-Peru). Results: LC50 values gradually decreased after 48 h of exposure for both compounds individually and as a mixture. The proportion-synergy (PS) was calculated in ratios of 1:1, 3:2 and 4:1 (arochlor 1254: Pb2+), obtaining higher PS values in 3:2 and 4:1 in contrast to 1:1. Conclusions: the PNEC estimated arochlor 1254 concentration is similar to the conservation value of the aquatic environment category 4-E1 and E2, and the maximum concentration for Pb2+ is not adequate and should be reduced to strengthen the conservation of aquatic biota. Finally, the bioindicator D. magna ideally determined the mixture of aroclor 1254 and Pb2+. [ABSTRACT FROM AUTHOR]

The red palm mite Raoiella indica Hirst has recently invaded the Neotropical region, which demands the implementation of pest management strategies. In this study, toxicity of leaf extracts of Mexican oregano Lippia berlandieri Schauer, neem Azadirachta indica A. Juss, Mexican mint Plectranthus amboinicus (Lour.) Spreng., rue Ruta graveolens L. and Persian lime Citrus x latifolia Tanaka against R. indica was evaluated under laboratory conditions. Raoiella indica females were exposed to each plant extract at concentrations of 0.25, 0.50, 0.75 and 1% (v/v) to assess the cumulative mortality at 24, 48 and 72 h after exposure. Mortality rates of R. indica rose due to increased extract concentration and exposure time. The strongest acaricidal activity was observed with L. berlandieri, A. indica and P. amboinicus, whose 1% concentration and 72 h exposure caused a mean R. indica mortality of 100, 90 and 78%, respectively. These plant extracts hold promise for the chemical management of this pest. [ABSTRACT FROM AUTHOR]

Plant derived volatiles are cues used widely that guide the behavior of plant associated insects, influencing both the ability of insects to locate host plants, as well as tritrophic interactions with predators or parasitoids. Therefore, an understanding of how volatiles impact a specific ecological system may aid the development of plants that are less attractive to pests or more amenable to biocontrol. Because each plant-insect interaction is different, it is important to develop bioassays to compare plants with different volatile profiles and assess their comparative attractiveness to specific insects. To this end, we developed a laboratory-based pair-wise choice assay to determine the oviposition preference of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), a global crop pest, to maize, Zea mays L. (Poaceae) plants with different volatile profiles. An alterna- tive greenhouse-based assay also was developed to assess the effect of different Z. mays plants on the oviposition behavior of Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp that can be used as a biocontrol agent for S. frugiperda. These bioassays are easily adaptable for use on a range of plant-insect interactions. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Entomología is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) is among the world's worst invasive species, and there is an increasing need for effective control methods for this species. Existing chemical treatments and baits used in managing other invasive ant species may not be as effective for managing W. auropunctata. Development of effective ant control treatments and baits depends on laboratory experiments to test the potential efficacy of a large number of products and control methods prior to implementation of large-scale field studies. However, anecdotal evidence suggests that laboratory-raised W. auropunctata may respond differently than their wild counterparts to bait types, and if this is the case, laboratory trials may not accurately predict results under field conditions. Here we report on experimental research investigating whether ant colonies raised in laboratories, and those in the field, show different patterns of recruitment to non-toxic baits. Laboratory and wild colony recruitment to non-toxic Hawaii Ant Lab gel bait, pureed tuna, and 50% gelled sucrose solution was measured via multi-choice and no-choice field recruitment studies. Secondly, we discuss experiments testing whether the bait preference of laboratory-raised W. auropuncata varies with their base diet. We tested 4 base diets: (1) lipid rich, (2) protein rich, (3) carbohydrate rich, and (4) a "complete" diet with lipid, protein, and carbohydrates offered as a buffet. Overall, we found that laboratory colonies differed from wild W. auropunctata in their foraging behaviors in no-choice and multi choice experiments, particularly in their levels of recruitment to the Hawaii Ant Lab gel bait. This contrast indicates that experimental trials may give misleading indications of potential outcomes of field trials. Further research is needed on optimal laboratory diets for laboratory-reared ant colonies. However, our results suggest that behavioral differences may be mitigated if colonies are maintained on a nutritionally limited diet while conducting laboratory experiments. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the toxicity of aqueous, ethanolic and acetonic extracts of Lantana camara L. (Verbenaceae), Ruta chalepensis L. (Rutaceae) and Rhazya stricta Decne (Apocynaceae), against larvae of Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), feeding on wheat seeds after 2, 4, and 6 days (d). These plants commonly grow in arid and semi-arid conditions and may provide novel natural insecticides against larvae of T. granarium. Results showed that the plant extracts demonstrated varying levels of toxicities, with the acetonic extracts providing the greatest efficacy. The acetonic extract of L. camara demonstrated a higher toxicity effect, with LC50 of 330.6 ppm (after 2-d) and 110 ppm (6-d), compared to 467 ppm (2-d) and 251 ppm (6-d) for R. stricta, and 576 ppm (2-d) and 317 ppm (6-d) for R. chalepensis. Overall, toxicity of acetonic extracts was about 1.3 fold greater compared with that of aqueous or ethanolic extracts throughout the range of concentrations tested (50-400 ppm). The acetonic extracts required six days to achieve = 80% mortality of larvae. In conclusion, this study suggests that the acetonic extract of L. camara, R. chalepensis and R. stricta could be used as a sustainable method for controlling Khapra beetle, pest of stored grains. [ABSTRACT FROM AUTHOR]

Antecedentes: las larvas de Dermatobia hominis causan miasis subcutáneas en animales y humanos de las zonas neotropicales. Esto obliga a buscar alternativas eficientes y sostenibles para su control. Dentro de estas‚ destacan los productos tópicos‚ que presentan ventajas sobre los sistémicos. Para las investigaciones con estos productos tópicos se requieren ensayos in vivo‚ pues se carece de pruebas in vitro. Objetivo: diseñar y estandarizar una prueba in vitro para la evaluación de productos tópicos para el control de D. hominis. Métodos: se colectaron 112 larvas procedentes de una miasis natural en bovinos; se lavaron con solución salina fisiológica y Gentamicina (80 mg/mL); posteriormente cada larva se depositó en viales estériles que contenían MEM Eagle y se transportaron al laboratorio de parasitología de la Universidad de Ciencias Aplicadas y Ambientales. Las larvas se distribuyeron de manera homogénea en cuatro grupos y se agregó a cada vial un tratamiento diferente: T1-Diclorvos 10 %; T2- Ivermectina 1 %; T3-Dimetil sulfoxido y T4- Solución salina fisiológica. Se estableció como tiempo de evaluación de muerte larvaria los minutos: 1‚ 60‚ 240‚ 1440‚ 2880 y 4320 postratamiento. Se realizó un análisis de supervivencia de Kaplan-Meier utilizando el programa GraphPad Prism‚ seguido de una prueba de rango logarítmico con comparaciones por pares para determinar las diferencias en la supervivencia de las larvas entre los tratamientos. Así mismo‚ se analizó la mortalidad bruta y mortalidad ajustada de Abbott. Resultados: se encontró que los tratamientos T1 y T2‚ tienen una mortalidad del 50 % alrededor de los 240 minutos de iniciado el ensayo‚ mientras que los tratamientos T3 y T4 alcanzan el 50 % de mortalidad cerca de los 1440 minutos. Por otro lado‚ los tratamientos T1 y T2 comparados con T3 y T4‚ tuvieron diferencias significativas (p < 0‚0001)‚ mostrando efecto en la probabilidad de supervivencia. Conclusión: el bioensayo larvicida demostró ser una herramienta útil para evaluar la eficacia de los diferentes preparados de uso tópico empleados. Este bioensayo fue rápido‚ sencillo y confiable para monitorear la eficacia de los productos evaluados. [ABSTRACT FROM AUTHOR]

Introduction: Use of allelochemicals as inexpensive, biodegradable and eco-friendly substitutes for the management of weeds in crops is a central topic nowadays. Objective: The current study represented the comprehensive screening of allelopathic activity of 73 weeds in Pakistan by the Sandwich method and dish pack method. To investigate the allelochemical compound in top most allelopathic weed. Methods: Allelopathic effects of selected weeds leaves leachate were determined through sandwich technique, while volatile allelopathic effects through dish pack techniques. Qualitative and quantitative phytochemical techniques were applied to investigate allelochemical potential of Melilotus indicus. The statistical analysis of the data described the allelopathic effect of 73 weed plants on lettuce seedling growth in terms of radicle and hypocotyl elongation. Results: Elongation percentage of radicle and hypocotyl ranged 0-74 % to 0-148 % and 0-75 % to 0-84 % respectively at 10 mg concentration of dry plant powder in sandwich method while it was 2-234 % and 7-150 % at in Dish Pack method. Among the plants screened for phytotoxic activity, M. indicus contained the strongest allelochemicals. Qualitative and quantitative analysis of M. indicus showed the presence of flavonoids and phenolic compound along with other allelochemical. Conclusions: Selected weeds may have strong allelochemical potential that can help in the development of bioactive compounds from plant species to be used as natural herbicides and pesticides for sustainable management of weeds and pest. [ABSTRACT FROM AUTHOR]

The marine-estuarine polychaete Capitella capitata is an endobenthic species which is considered as a cosmopolitan organism. The laboratory culture of this species-complex allows its use as a test species in toxicity bioassays and reproduction studies. Objective: It is pretended to observe mortality under two temperature and salinity ranges as optimal conditions to culture Capitella sp. in the laboratory. Metodology: Polychaetes were collected in Callao Province, Peru, during November 2016 and January 2017. A bioassay was carried out to observe mortality under different temperature and salinity ranges using two treatments: treatment 1, with polychaetes collected during January 2017, which were subjected to conditions similar to the collection site (temperature: 20-22° C, salinity: 30-32 psu); treatment 2, with the organisms collected during November 2016, with temperature (24-26 °C) and salinity (32 a 34 ups) selected according to bibliographic data. Results: The increase of temperature and time significantly influenced polychaete mortality of the two treatments (Spearman correlation), while salinity and dissolved oxygen did not show correlation with mortality. Significant effect of time was observed on mortality, with more deaths from the second half of the experiment. Organisms from treatment 1, with environmental conditions similar to those of their habitat survived more than worms from treatment 2. These results were also observed in the porcentual varibility of the variation coefficient among days in each treatment. The cumulative mortality curve did not show differences between treatments. Conclusion: The optimal ranges to culture Capitella sp. in the laboratory are those from their habitat. In addition to temperature and time, other posible causes of the observed mortality can be worms age, health or maturity, and probably the bad quality of the water used during the bioassay. [ABSTRACT FROM AUTHOR]

Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of non-conventional insecticides and entomopathogenic fungi to control adult mosquitoes is increasing; however, the current methods are designed to evaluate the insecticidal action of the active ingredient. We describe the bioassay method to evaluate the effect of non-conventional insecticides and entomopathogenic fungi to control mosquitoes using the Potter tower. Twenty d after application, entomopathogenic fungi produced a proportion of mortality of 0.49 to 0.82, while non-conventional insecticides produced 100% mortality from 15 min after application. Our results showed that this bioassay could provide basic information on the effect of different non-conventional insecticides and entomopathogenic fungi on adult mosquitoes. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Toxicología is the property of Asociacion Espanola de Toxicologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de Toxicología is the property of Asociacion Espanola de Toxicologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vitrofural® is an additive used for the chemical sterilization of plant culture media in the in vitro propagation of plants. At the end of its use, it becomes a waste of the biotechnological process and is dumped into confined terrestrial environments. Nevertheless, the possible ecotoxicological impacts that could occur are unknown. The aim of this work was to determine the acute toxicity of earthworms (Eisenia foetida) by exposure to Vitrofural® residues on agar. The toxic potential of the waste was evaluated by single exposure to earthworms for 14 days. Worms were exposed by contact and ingestion at a concentration corresponding to the maximum possible to be obtained from lixiviate of the solid residue of Vitrofural® on agar, after 7 and 21 days of preparation. The number of dead animals and the loss of body mass were quantified, and the sublethal toxic signs were described. In the experimental groups there was no mortality, only slight morphological and physiological alterations were observed with a tendency to decrease in frequency in the group exposed to the lixiviates with 21 days of preparation. Similar response was observed in the evolution of body mass. The lixiviated of Vitrofural® in agarized medium induce slight sublethal effects in earthworms a function of the preparation time and demonstrate the absence of ecotoxicological risk due to exposure in this specie. [ABSTRACT FROM AUTHOR]

Esta investigación se realizó con el objetivo de evaluar una estrategia agroecológica para el manejo del pasador del fruto Neoleucinodes elegantalis. Fueronevaluados tres tratamientos homeopáticos CH4, CH7 y CH14, utilizando el principio de la isopatía. Mediante bioensayos se probaron tres soluciones homeopáticas, lassolucionesCH4 y CH7 presentaron un menor número de huevos y larvas por fruto, según la prueba de Duncan estas mostraron diferencias estadísticas significativas comparadas con el testigo. Para la variable porcentaje de eclosión de huevos no presentaron diferencias estadísticas entre los tratamientos, luegoen campo se comparó la solución homeopática (CH4) con un testigo absoluto. Los resultados de este ensayo indicaron un menor número de frutos dañados por planta utilizando CH4, con diferencias significativas con el testigo, a partir de la tercera hasta la séptima evaluación. En la variable porcentaje de pérdidas de fruto ocasionados por la plaga se presentaron diferencias estadísticas a partir de la tercera evaluación a favor de la solución CH4 la que presento el menor daño. Este estudio permitió reconocer la eficacia de las soluciones homeopáticas en el control de Neoleucinodes elegantalis, además se proyecta como base para estudios agroecológicos y homeopáticos posteriores en el manejo integrado de plagas.

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae), is a pest recently introduced to Mexico, and is under epidemiological surveillance. In order to reduce its expansion and damage, several phytosanitary activities are carried out, including sampling, diagnosis, and control of infestation points, by means of sanitary pruning and application of acaricides. Acaricides are selected based on effectiveness tests developed in other countries where the R. indica local populations may have a different response to those acaricides. The aim of this study was to determine the toxicity of 14 acaricides in a red mite R. indica population collected in Tabasco, Mexico. Bioassays were conducted under laboratory conditions, placing R. indica adult females on leaf blade pieces of coconut palm (Cocos nucifera L.) impregnated with acaricide solutions. Twenty-four hours after application, mite mortality was evaluated and the Probit procedure was used to analyze the data. According to the lethal concentration 50 % (LC50) and 90 % (LC90), the most toxic acaricides to R. indica adults were fenazaquin and milbemectin, followed by abamectin and dicofol. Acequinocyl, fenpyroximate, propargite, formetanate hydrochloride, sulfur, and bifenthrin were less toxic. These results provide information for the chemical control of this pest and to lay the foundations for a strategy to make a rational use of acaricides. In addition, they should be complemented with biological effectiveness information of these products in situ, proper application timing, and how to minimize the impact on R. indica's natural antagonists. [ABSTRACT FROM AUTHOR]

Se evaluó el efecto insecticida de tres extractos de la planta endémica de Chile, Lepechinia chamaedryoides (Balb.) Epling (extracto polar, exudado resinoso y aceite esencial), sobre larvas del díptero Drosophila melanogaster Meigen con el fin de determinar cuál o cuáles de éstos poseen actividad biológica insecticida. El bioensayo se realizó sobre la base de un diseño experimental completamente aleatorio, con 15 tratamientos y tres repeticiones, que contempló el estudio de variables de mortalidad y de concentración letal 50 % (CL50) y 90 % (CL90), y observación de organismos mediante lupa, microscopía óptica y microscopía electrónica de transmisión. Se registró una mortalidad mayor al 90 % en cuatro concentraciones evaluadas del aceite esencial. En el caso de extracto polar y exudado resinoso no hubo diferencias significativas entre las distintas concentraciones evaluadas, respecto al control, presentándose valores de mortalidad inferiores a un 23 %. La concentración letal 50% (CL50) del aceite esencial fue de 0,46 % v/v y la concentración letal 90% (CL90) de 0,77 % v/v. Se observaron cambios en la morfología externa e interna de las larvas en el tercer estado. Externamente, se observó oscurecimiento de la cutícula y un aumento de volumen del organismo. Internamente, se observó una fragmentación de las glándulas salivales además de diferencias en los tubos de Malpighi y discos imaginales en relación al grupo control. A nivel celular, también se presentaron cambios, entre ellos, variaciones en aspecto de organelos como en retículo endoplasmático rugoso, mitocondrias y aparato de Golgi.With the aim to assess its biological activity, three extracts of a Chilean endemic plant, Lepechinia chamaedryoides (Balb.) Epling (polar extract, resinous exudate and essential oil) were evaluated for its insecticidal activity on Diptera larvae, Drosophila melanogaster Meigen. The bioassay was conducted on the basis of a completely randomized experimental design with 15 treatments and three repetitions, which includes the study of mortality variables and 50% lethal concentration (LC50) and 90% (LC90), in addition to the observation of organisms through a magnifying glass, optical microscopy and transmission electronic microscopy. Mortality was recorded over than 90% in four tested concentrations of essential oil. In the case of polar extract and resinous exudate no significant differences between the different concentrations tested and controls, with mortality values lower than 23%. The lethal concentration 50% (LC50) of essential oil was 0,46% v/v and the lethal concentration 90% (LC90) of 0,77 % v/v. There were changes in the external and internal morphology of the third stage larvae. Externally, there was darkening of the cuticle and a volume increase of the body. Internally, there was a fragmentation of the salivary glands as well as differences in the Malpighian tubes and imaginal discs in relation to control group. At the cellular level, there were also changes, including changes in organelles like in rough endoplasmic reticulum, mitochondria and Golgi apparatus.

Colacium vesiculosum (Euglenophyceae) is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton Colacium vesiculosum Ehrenberg (Euglenophyceae) es un epibionte común en microcrustáceos del plancton de aguas continentales. La interacción epibiontes y organismo substrato es poco conocida, particularmente en ambientes subtropicales de América del Sur. Se analiza la prevalencia, densidad, biomasa y sitios de adhesión de C. vesiculosum en microcrustáceos planctónicos de un lago subtropical de Argentina. Con el fin de evaluar si los epibiontes afectan la tasa de filtración de Notodiaptomus spiniger Brian, crustáceo dominante del zooplancton, se realizaron bioensayos utilizando el fitoplancton

A reliable bioassay procedure was developed to test ingested Bacillus thuringiensis (Bt) toxins on the rice delphacid Tagosodes orizicolus. Initially, several colonies were established under greenhouse conditions, using rice plants to nurture the insect. For the bioassay, an in vitro feeding system was developed for third to fourth instar nymphs. Insects were fed through Parafilm membranes on sugar (10 % sucrose) and honey bee (1:48 vol/vol) solutions, observing a natural mortality of 10-15 % and 0-5 %, respectively. Results were reproducible under controlled conditions during the assay (18±0.1 °C at night and 28±0.1 °C during the day, 80 % RH and a 12:12 day:light photoperiod). In addition, natural mortality was quantified on insect colonies, collected from three different geographic areas of Costa Rica, with no significant differences between colonies under controlled conditions. Finally, bioassays were performed to evaluate the toxicity of a Bt collection on T. orizicolus. A preliminary sample of twenty-seven Bt strains was evaluated on coarse bioassays using three loops of sporulated colonies in 9 ml of liquid diet, the strains that exhibited higher percentages of T. orizicolus mortality were further analyzed in bioassays using lyophilized spores and crystals (1 mg/ml). As a result, strains 26-O-to, 40-X-m, 43S-d and 23-O-to isolated from homopteran insects showed mortalities of 74, 96, 44 and 82 % respectively while HD-137, HD-1 and Bti showed 19, 83 and 95 % mortalities. Controls showed mortalities between 0 and 10 % in all bioassays. This is the first report of a reliable bioassay procedure to evaluate per os toxicity for a homopteran species using Bacillus thuringiensis strains. Rev. Biol. Trop. 55 (2): 373-383. Epub 2007 June, 29.Se desarrolló una metodología de bioensayo para evaluar toxinas de Bacillus thuringiensis (Bt) ingeridas por Tagosodes orizicolus, plaga del arroz y vector del virus de la hoja blanca. Se establecieron colonias del insecto en condiciones de invernadero usando plantas de arroz como alimento. Para el bioensayo, se desarrolló un sistema de alimentación in vitro para ninfas de tercer y cuarto estadío. Los insectos se alimentaron de soluciones de miel de abeja (1:48 vol/vol) y sacarosa (10 %) a través de membranas de Parafilm. Se observaron mortalidades del 10-15 % y 0-5 %, respectivamente, en ambas dietas. Los resultados fueron reproducibles en condiciones controladas de humedad y temperatura (18±0.1 °C de noche y 28±0.1 °C de día, 80 % H.R y a 12:12 fotoperíodo día:noche). Asimismo, se analizó la mortalidad natural de los insectos según su procedencia, sin embargo, no se observaron diferencias significativas en condiciones controladas. Finalmente, se elaboraron bioensayos para evaluar la toxicidad de una colección de cepas de Bt contra T. orizicolus. Se evaluó preliminarmente, una submuestra de 27 cepas de Bt en bioensayos burdos usando tres asadas como inóculo para 9 ml de dieta líquida. Posteriormente, las cepas que mostraron los mayores porcentajes de mortalidad se evaluaron en bioensayos usando esporas y cristales liofilizados (1 mg/ml). Como resultado, las cepas aisladas a partir de homópteros 26-O-to, 40-X-m, 43-S-d y 23-O-to mostraron mortalidades de 74, 96, 44 y 82 % respectivamente, mientras que las HD-137, HD-1 y Bti mostraron 19, 83 y 95 % de mortalidad. Los controles presentaron mortalidades de 0 y 10 % en los bioensayos. Este es el primer informe de un bioensayo para evaluar la toxicidad de cepas de Bt utilizando la especie T. orizicolus.

El objetivo del trabajo fue evaluar la toxicidad del cobre y arsénico en suelos agrícolas, mediante bioensayos estandarizados de toxicidad aguda y crónica sobre Eisenia foetida y relacionar la respuesta de ésta con las concentraciones de cobre y arsénico en los suelos. Los suelos agrícolas fueram muestreados en las inmediaciones de áreas mineras en la cuenca del río Aconcagua, Chile. E. foetida expuesta a los suelos estudiados mostró una baja mortalidad, indicando la ausencia de toxicidad aguda. Además, se observó una disminución en la producción de capullos y desarrollo de juveniles, indicando la existencia de toxicidad crónica. Dicha disminución fue relacionada con las concentraciones de cobre y arsénico en los suelos. El cobre y arsénico en conjunto disminuyeron la producción de capullos, mientras que sólo el arsénico disminuyó el desarrollo de juveniles. Suelos agrícolas provenientes de áreas mineras de la cuenca poseen potenciales características tóxicas para el desarrollo de la macrofauna edáfica.The objective of this work was to evaluate copper and arsenic toxicity in agricultural soils, by means of standardized bioassays of chronic and acute toxicity on Eisenia foetida, and to relate E. foetida response to copper and arsenic concentrations in soils. The agricultural soils were sampled in the proximity of copper mining industries, in the Aconcagua river basin, Chile. E. foetida exposed to the studied soils exhibited a low mortality, indicating the absence of acute toxicity. Besides, a decrease in the cocoon production and juvenile development was observed, indicating the existence of chronic toxicity. Reduction in the cocoon production and juvenile development was related to soil concentrations of copper and arsenic. Both copper and arsenic reduced the cocoon production, while only arsenic diminished the juvenile development. Agricultural soils from mining areas of the basin have potentially toxic characteristics for the development of soil macrofauna.

Se evaluó el impacto ecotoxicológico del insecticida carbámico cartap (1,3 di (carbamoytio)-2-dimetiloaminopropano) usado para el control de plagas agrícolas y como molusquicida de vectores de importancia en Salud Pública, sobre dos especies de peces del ecosistema acuático continental: Poecilia reticulata (Peters 1859) "guppy" (Poecilidae) y Paracheirodon innesi (Myers 1936) ``Neon Tetra" (Characidae). Ellos fueron utilizados como organismos no destinatarios en ensayos de corta duración, para determinar el impacto toxicológico del cartap. Para ambas especies de peces se evaluó el porcentaje de mortalidad, y dos respuestas subletales: el incremento del movimiento opercular y el nado extraño. A 3 h de exposición para P. reticulata, se encontró un valor de CL50 (Concentración letal media) de 6,75 mg•L-1 y valores de CE50 (Concentración efectiva media) de The ecotoxicological impact of the carbamate insecticide cartap (1,3 di (carbamoythio)-2-dimethyloaminopropan) used for agriculture pests and as mollusquicide of vectors of Public Health importance was evaluated, on two fish species of the continental aquatic ecosystem. Poecilia reticulata (Peters 1859) ``guppy" (Poecilidae) and Paracheirodon innesi (Myers 1936) ``Neon Tetra" (Characidae) were employed as non-target organisms in assays of short duration to determine the toxicological impact of cartap. For both fish, percentage of mortality and two sublethal responses: increase of opercula movement and strange swim, were evaluated. In P. reticulata after 3 h exposure it was found a LC50 (mean Lethal Concentration) of 6.75 mg'•L-1 and values of EC50 (mean Effective Concentration) of

This research evaluated the insecticidal activity of various native isolates of Bacillus thuringiensis against Spodoptera frugiperda, From Soils of Funza and Silvania (Cundinamarca) Tunja (Boyacá) in crops of beans, peas, maize and orange compared with a commercial witness HD1 (subsp. Kurstaki) against S. frugiperda. LC50 lethal concentration average was initially determined by the "probit" method, which was 5.88 E-4 mg ai / ml of diet, strain HD1 with different doses (0.0; 6.8 E-2; 3.4E-2 ; 6.8E-3; 6.8E-4; 6.8E-5 6.8E-6 and ai mg / ml diet) in first instar larvae S. frugiperda. In addition to qualitative observations mortality was measured at 96 and 120 hours. Subsequently the determined median lethal concentration (LC50) with strain HD1 proceeded to use this concentration in each native B. thuringiensis isolates to be compared with the commercial control CL50. Design was completely randomized with 7 treatments (each with 25 first instar larvae) and 3 replications. For the second test determining promissory isolates of Bt, a completely randomized design with 11 treatments (each with 20 first instar larvae) and 3 replications was arranged. Results indicated that M3008 and M4001 native isolates have higher mortality averages, which were 75% and 71.65% respectively in first instar larvae in purified diet, compared with mortality LC50 of commercial control. [ABSTRACT FROM AUTHOR]

Glyphosate is an herbicide that is widely used in Colombia not only for farming, but also for illicit crop eradication. Wind drift in air spraying and the lixiviation of this product can contaminate water bodies and for this reason, it is important to measure its toxic effect. Fish such as the Poecilla reticulata were submitted to concentrations of 0; 2.3; 5.5; 8.3; 11.0; 13.8 mg of glyphosate/L in the commercial formula Roundup® 747 SG/L to determine the mortality of treated individuals and the lethal concentration 50 (LC50-96) in lab conditions. Mortality was tested at 24, 48, 72, and 96 hours, and we were able to find that it increased as the herbicide concentration and the time elapsed increased. We also noticed a variation in the swimming pattern of the fish studied. The value of the 50-lethal concentration glyphosate over P. reticulata during the first 96 hours that the treatment was applied was of 3.14 mg/L, which suggests an ecological impact in natural ecosystems and a potential use of this type of fish as a contamination bioindicator for this herbicide in extreme toxicity tests. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Innotec is the property of Laboratorio Tecnologico del Uruguay and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fitosanidad is the property of Instituto de Investigaciones de Sanidad Vegetal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is an economically significant pest of sorghum and maize. Laboratory bioassays are often conducted for convenience and for fall armyworm confinement but as the number of entries and replications increase, the replenishing of fresh tissue daily and the cleaning of insect diet cups or petri dishes becomes laborious. The current study was conducted to determine if agar plates, used to retain leaf moisture, supplemented with benzimidazole, a fungicide that delays leaf senescence and retards fungicide growth, can be used to assess fall armyworm feeding on fresh maize and sorghum leaf tissue with minimal labor. We conducted 2 trials consisting of 3 cultivars of maize with known resistance or susceptibility to fall armyworm feeding, and 4 cultivars of sorghum that are parents of existing mapping populations. The top 2 (whorl) leaves were removed from 36-37- day old plants, 7.6 cm long pieces of leaf were excised, and each piece was placed on a benzimidazole agar plate. One larva per plate was placed on the leaf tissue; the plate was sealed with Parafilm and placed in an incubator for 7 days. Average larval weights for Trial 1 were significantly different than Trial 2 after 7 days, and thus each trial was analyzed separately. For both trials, the larvae that were fed susceptible maize line 'AB24E' had weights that were significantly greater than larvae fed resistant maize lines 'Mp708' and 'FAW1430'. No significant differences in weight were observed for fall armyworm larvae fed on the 4 sorghum lines except for those larvae fed 'Collier' in Trial 2, which had weights significantly greater than larvae fed the other 3 sorghum cultivars (Entry 22, 'Honey Drip', 'AN109'). Thus, the benzimidazole agar plate method is an easy and effective method for assessing fall armyworm feeding on maize and sorghum, and thus can be used to identify maize and sorghum germplasm lines with resistance to fall armyworm. [ABSTRACT FROM AUTHOR]

In Colombia, the vigilance of the Maximum Residue Limits MRLs of veterinary antimicrobials in cattle meat is limited, because the analytical capacity is insufficient to monitor a large number of samples and a wide range of antibiotics. The bioassay is a microbiological method developed by the health public agency (FSIS) of the United States Department of Agriculture (USDA) for the detection, identification and semiquantification of antimicrobial residues in cattle muscle. Objective: It was evaluated preliminary the bioassay for use as a test for the qualitative detection for monitoring and surveillance of four antimicrobials in cattle muscle, as contribution to the inocuity management system within the agreement framework about the application of Sanitary and Phytosanitary Measures; using some guidelines of the European Decision 2002/657/EC. Methods: The experimental protocol used fortified tissues with varying concentrations of penicillin G potassium, Oxytetracycline, erythromycin and streptomycin, as representatives of the four important families of veterinary antibiotics used in Colombia. To establish the performance criteria of the bioassay were prepared six replicates of each of the levels or concentrations tested for antimicrobial, including a level without fortification and five levels of lower antibiotic concentrations, equal and above MRL Maximum Residue Limit for each one of the tested antimicrobials. Results: The performance characteristics of method were preliminarily determined (specificity, detection limits and stability). The test showed excellent specificity (no false positive); detection limits were determined for the four antibiotics in relation to their respective Maximum Residue Limit MRLs: Beta-lactams (penicillin G =MRL), tetracyclines (Oxytetracycline =MRL), macrolides (erythromycin =MRL) and aminoglycosides (streptomycin >4 MRL); however, the sensitivity of bioassay for the streptomycin was unsatisfactory. Stability of the analytes in the matrix was adequate during the period evaluated. Conclusions: The preliminary bioassay method evaluated is applicable to the detection of a broad range of antimicrobial residues in bovine muscle at concentrations at the MRLs. [ABSTRACT FROM AUTHOR]

The genus Leptolyngbya comprises filamentous cyanobacteria that are important in rice fields. In the rhizosphere, cyanobacteria produce a variety of secondary metabolites such as auxins that are important in agriculture soil performance. To assess this, Leptolyngbya strain MMG-1, was isolated from the rhizosphere of rice plants and described. For this, the morphology of this strain was studied by light microscopy as well as by confocal laser scanning microscopy. Besides, the ability of this strain to synthesize an auxin-like bioactive compound was demonstrated under various culture conditions (different amounts of tryptophan; pH; different alternating light:dark periods; duration of the incubation). The auxin-like compound was extracted from the culture of Leptolyngbya strain MMG-1 and identified as indole-3-acetic acid (IAA) by thin layer chromatography (TLC) as well as by high performance liquid chromatography (HPLC). Our results showed that the strain required the precursor L-tryptophan for the synthesis of IAA. Leptolyngbya strain MMG-1 accumulated IAA intracellularly. The IAA secreted by Leptolyngbya strain MMG-1 was significantly correlated with the initial concentration of L-tryptophan in the medium, as well as with the duration of the incubation. The bioactivity of the secreted IAA was determined by its effect on the rooting pattern of Pisum sativum seedlings. The culture supernatant of Leptolyngbya strain MMG-1 stimulated the seedling lateral rooting, while it decreased root length. Hence, rhizospheric Leptolyngbya produced auxin under different conditions and affected the plants rooting pattern. Rev. Biol. Trop. 62 (3): 1251-1260. Epub 2014 September 01. [ABSTRACT FROM AUTHOR]