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La presente investigación tuvo como objetivo conocer el índice verde y la disponibilidad de parques en las alcaldías de mayor densidad poblacional en la Ciudad de México. Fue realizado mediante un análisis cuantitativo sobre bases de datos poblacionales proporcionados por el Instituto Nacional de Estadística y Geografía (INEGI) y Consejo Nacional de Población (CONAPO) para 2017 y 2020. El índice verde y la disponibilidad se calcularon mediante el geoprocesamiento de las áreas verdes correspondientes a parques de acuerdo con el Levantamiento de Áreas Verdes del 2017, considerando el portal de datos abiertos del gobierno de la Ciudad de México. Los datos geoestadísticos, fueron ajustados mediante la agrupación de polígonos y recálculo de áreas, no modificando la vectorización original. Los resultados indican que la alcaldía de Iztapalapa es la que mayor disponibilidad de parques tiene (259) y el mayor índice verde de áreas verdes en parques con un valor de 1.64 m2hab-1. Iztacalco, que es la alcaldía con mayor densidad de población registra un índice de 0.2 m2hab-1. Lo anterior refleja la enorme necesidad que existe de abrir espacios verdes recreativos a efecto de equilibrar la densidad de población con su índice verde en parques.

Melanaphis sacchari Zehntner (Hemiptera: Aphididae) is currently the most destructive pest insect of the sorghum crop (Sorghum bicolor L. Moench) and has caused economic losses worldwide. Strategies using natural products such as plant extracts can offer alternatives for the control of this pest. In this investigation, we evaluated the insecticidal effect of the hexane extract of Ricinus communis L. and Momordica charantia L. seeds on M. sacchari in contact bioassays. The results showed that the extract of R. communis presented a mortality rate of 100% in 48 h at 10,000 ppm, while M. charantia presented 80% in 72 h, at 10,000 ppm. Gas chromatography—mass spectrometry (GC–MS) identified the major compounds as squalene in R. communis (51.57%) and linalool oxide in M. charantia (30.45%). The hexanic extracts of these plant species could be considered an ecologically friendly alternative to control this pest, given the use of synthetic chemical insecticides.

Some botanical extracts affect the cellular immune system of insects by interfering with normal hemocyte function. This gives rise to diminution in cellular immunity and causes a decrease in insect...

The biological activity of extracts from Trichilia americana (Sesse and Mocino) T.D. Penn. (rind), Carica papaya L., Jatropha curcas L., Ricinus communis L., and Lupinus campestris Schldl. & Cham. (seeds), at 1% and 5%, were evaluated on neonates of Copitarsia decolora Guenée in ingestion bioassays. The plants that caused the highest percentage of larval mortality were T. americana at 1% and 5%, and Carica papaya at 5% with 98% and 100% and 100%, respectively. Trichilia americana was the plant with higher toxicological properties against C. decolora. Extracts in hexane, ethyl acetate, acetone, and methanol from T. americana were then evaluated at 10, 100, 300, and 1,000 ppm also in ingestion bioassays against C. decolora. Extracts of ethyl acetate and acetone at 1,000 ppm recorded the highest percentages of larval mortality of C. decolora (90% and 55%, respectively). In addition to larval mortality, feeding on T. americana extract also decreased mean larval weight, prolonged duration of the larval stage, resulted in malformed pupae and adults, and affected adult fertility and fecundity. Finally, these extracts were evaluated in a toxicity model, for which the crustacean Artemia salina Leach was used. The ethyl acetate, acetone, and hexane extracts showed no toxicity to A. salina, while the methanol extract caused 30% mortality, which is considered to be slightly toxic. Based on the results obtained, T. americana is a species with insecticidal and insectistatic activity against C. decolora and can be considered as a potential insecticide for the management of this or other insect pests.

Castor bean (Ricinus communis) seeds contain ricinine, an alkaloid with insecticidal and insectistatic activities. Elicitation with salicylic acid (SA) has proven to stress R. communis and might modify the ricinine concentration. The aim of this study was to evaluate the concentration of ricinine in the bagasse of seeds from R. communis elicited with exogenous SA under greenhouse conditions. Plants were grown and divided into five groups, which were sprayed with SA and drench with 50 mL 60 days after sowing with concentrations of SA (0, 100, 300, 600 and 900 µM). Clusters were mixed and separated according to the treatment, and dried. The seeds were ground, the oil was extracted by Soxhlet with hexane, and then the bagasse was extracted with methanol. Ricinine was determined by HPLC. Elicitation did not change the plant height or diameter, the control group had 9.17 µg mL−1 of ricinine, and the concentrations followed a hormesis curve with the peak at 300 µM of SA that had a ricinine concentration of 18.25 µg mL−1. Elicitation with SA might be a cost-effective technique to increase ricinine from R. communis bagasse.

The main objective of the study was to identify chemical compounds of extract of acetone of shell + almond (EACA) and nut of almond (EAA) of Jatrofa curcas and evaluate bioactivity against Copitarsia decolora in laboratory and greenhouse conditions. In ingestion experiments, extracts at 250, 500, 1,000, 1,500, and 2,000 ppm were mixed into artificial diet. Checks were artificial diet mixed with a botanical insecticide Margosom® 0.3% EC (active ingredient [AI] 250 ppm, azadirachtin), and diet plus only water. EAA at 250 and 1,000 ppm inhibited larval weight and prolonged larval development of C. decolora. EAA at 500 ppm and EACA at 1,500 ppm caused most deformation in pupae and adults. As many as 50% of C. decolora larvae occurred with EAA at 500-. EAA was the most active extract in laboratory tests and later evaluated at 250, 500, and 1,000 ppm applied to cabbage plants infested with C. decolora larvae in a greenhouse. Two checks were cabbage (Brassica oleracea var. capitata) plants without extract (water only) and pyrethroid insecticide (Alfadex® AI 21.29% cypermethrin) at 500 ppm. Gas chromatography-mass spectrometry (GC-MS) analysis of the acetonic extract of Jatropha curcas seed identified oleic acid as the major compound. EAA at 1,000 ppm and Alfadex were most effective at protecting cabbage plants from attack by larval C. decolora.

Resumen Introducción: Montanoa tomentosa es un recurso fitogenético con propiedades medicinales utilizada en México. A pesar de su relevancia para la botánica, la información específica sobre la distribución de sus taxa infraespecíficos y los factores ambientales que influyen en su desarrollo aún es limitada. Objetivo: Informar sobre la distribución geográfica potencial y las variables ambientales asociadas a los nichos ecológicos de dos subespecies de M. tomentosa(M. tomentosa subsp. tomentosa y M. tomentosa subsp. xanthiifolia), dentro del territorio mexicano. Métodos: Se elaboró una base de datos con registros de herbario. Posteriormente, se realizó una búsqueda sistemática in situ de plantas de ambas subespecies entre octubre 2015 y marzo 2016 durante la época de floración-fructificación. Se realizaron recorridos exploratorios en los estados de Guanajuato, Querétaro, Hidalgo, Ciudad de México, Estado de México, Puebla, Oaxaca y Chiapas. Un total de 181 plantas fueron ubicadas y georreferenciadas. La base de datos se complementó con los nuevos registros (un total de 314). Se generaron tres modelos de idoneidad del hábitat (complejo de M. tomentosa, M. tomentosa subsp. tomentosa y M. tomentosa subsp. xanthiifolia) con el software MaxEnt, el cual estima la probabilidad de distribución de especies a partir de datos georreferenciados y características ambientales como predictores, mediante el logaritmo de máxima entropía y el método bayesiano. Resultados: De 22 variables ambientales utilizadas como predictores, cinco (estacionalidad de la temperatura, isotermalidad, temperatura máxima del mes más cálido, precipitación del trimestre más cálido y precipitación del trimestre más lluvioso) contribuyeron con 70.2 % de la estimación total. El modelo arrojó una distribución potencial de 77 688 km2 aproximadamente, 4 % del territorio de la república mexicana. Ambas subespecies crecen a una altitud entre 500 y 2 500 m. Las heliófilas se asocian a vegetación xerófila y a veces se localizan en la periferia de bosques o enclavadas en claros de bosques templados y subhúmedos, pero no habitan en las regiones áridas y semiáridas del norte del país. Conclusiones: La estacionalidad de la temperatura, isotermalidad y temperatura máxima del mes más cálido determinan la distribución de la especie. La precipitación en el trimestre más cálido y la precipitación en el trimestre más lluvioso definen el hábitat entre M. tomentosa subsp. tomentosa y M. tomentosa subsp. xanthiifolia. Estos hallazgos aclaran las preferencias ecológicas y la delimitación de los taxa infraespecíficos de M. tomentosa. Abstract Introduction: Montanoa tomentosa is a phytogenetic resource with medicinal properties used in Mexico. Despite its botanic relevance, the specific information of infraespecific taxa distributions and the environmental factors that influence their development is still limited. Objective: To report the potential geographic distribution and the environmental variables associated to ecological niches of two subspecies of M. tomentosa (M. tomentosa subsp. tomentosa and M. tomentosa subsp. xanthiifolia) in the Mexican territory. Methods: A database of herbarium records was created, an in situ systematic search of both subspecies was carried out from October 2015 to March 2016, during the flowering-fruiting season. After that, exploratory tours (Guanajuato, Querétaro, Hidalgo, Mexico City, State of Mexico, Puebla, Oaxaca and Chiapas) were realized. A total of 181 individuals were sampled and georeferenced, generating new records for the database upgrading. Three habitat suitability models (M. tomentosa complex, M. tomentosa subsp. tomentosa and M. tomentosa subsp. xanthiifolia) were generated using the MaxEnt software. These software estimates the probability of species distribution using geo-referenced data and environmental characteristics as predictors, through the maximum entropy logarithm and the Bayesian method. Results: From 22 environmental variables used as predictors, five (seasonality of temperature, isothermality, maximum temperature of the warmest month, precipitation of the warmest trimester and precipitation of the wettest trimester) contributed 70.2 % of the total percentage contribution. The model showed a potential distribution of 77 688 km2, approximately 4 % of the Mexican Republic territory. Both subspecies grew between 500 and 2 500 m. They were associated to xerophilous and heliophiles vegetation, sometimes they were located in the periphery or embed in openings of temperate and sub-humid forests too. They were not present dry regions from the North of the country. Conclusions: Temperature seasonality, isothermality and maximum temperature of the warmest month determine the distribution of the species. Precipitation of the warmest quarter and precipitation of wettest quarter defines the habitat between M. tomentosa subsp. tomentosa and M. tomentosa subsp. xanthiifolia. These findings clarify the ecological preferences and delimitation the infraspecific taxaof M. tomentosa.

The repeated application of synthetic insecticides has the potential to induce insecticide resistance. Plant extracts are a good source of bioinsecticides, as these extracts often have several bioactive compounds, thus reducing the occurrence of resistance. The genus Trichilia (Meliaceae) is distributed widely in Mexico and it is a sustainable source of bioactive compounds because their bark is shed annually and may be collected without harming the tree. This research evaluated the effect on mortality, weight, larval and pupal duration, fecundity, and fertility of Copitarsia decolora Guenee (Lepidoptera: Noctuidae) when fed with a diet supplemented with different concentrations of hexane, ethyl acetate, acetone, methanol, and aqueous extracts of the Trichilia americana Sesse & Moc., Trichilia hirta L., and Trichilia havanensis Jacq. (Meliaceae) bark. All the extracts provoked a dose-response effect on the variables evaluated. The hexane extract of the 3 species was lethal to the larval stage, with the hexane extract of T.americana being the most toxic of the 3 species, followed by that of T. hirta. The aqueous extract of T. hirta displayed an insecticidal effect on the early instars. The ethyl acetate extracts of T. americana and hexane extracts of T. hirta inhibited growth and induced mortality. The extracts reduced fecundity and fertility of the insect. Extracts of T. americana reduced reproductive potential to a greater extent than did T. hirta and T. havanensis. This research suggests that bark extracts of T. americana, T. hirta, and T. havanensis are a sustainable source of biomolecules. ResumenLa aplicacion repetida de insecticidas sinteticos tiene el potencial de inducir resistencia a los insecticidad. Los extractos de plantas son una buena fuente de bioinsecticidas, ya que estos extractos a menudo tienen varios compuestos bioactivos, lo que reduce la apariencia de resistencia. El genero Trichilia (Meliaceae) esta ampliamente distribuido en Mexico y es una fuente sustentable de compuestos bioactivos ya que su corteza se desprende anualmente y puede recolectarse sin danar el arbol. Este trabajo evaluo el efecto sobre la mortalidad, peso, duracion de larvas y pupas, fecundidad y fertilidad de Copitarsia decolora Guenee (Lepidoptera: Noctuidae) al ser alimentadas con una dieta suplementada a diferentes concentraciones de extracto hexanico, acetato de etilo, acetonico, metanolico y acuoso de corteza de Trichilia americana Sesse & Moc., Trichilia hirta L., y Trichilia havanensis Jacq. (Meliaceae). Todos los extractos provocaron un efecto de dosis respuesta sobre las variables evaluadas. El extracto de hexano de las 3 especies fue letal para el estadio larval, siendo el extracto de T. americana el mas toxico de las 3 especies seguido por el de T. hirta. El extracto acuoso de T. hirta ocasiono un efecto insecticida en los primeros instares. Los extractos de acetato de etilo de T. americana y hexano de T. hirta inhibieron el crecimiento y provocaron mortalidad. Los extractos redujeron la fecundidad y la fertilidad del insecto. Los extractos de T. americana redujeron el potencial reproductivo en mayor medida que T. hirta y T. havanensis. Esta investigacion sugiere que los extractos de corteza de T. americana, T. hirta, y T. havanensis son una fuente sustentable de biomoleculas.View this article in BioOne

Los agricultores se enfrentan a problemas fitosanitarios de graves riesgos, generalmente se asume que el incremento del nitrógeno (N) en la planta aumenta las poblaciones de patógenos. El estudio se llevó en invernadero para conocer los efectos de las variables agronómicas de la espinaca (Spinacia oleracea L.) variedad Python F1, así como la respuesta que hay en la oviposición de las hembras y el daño que ocasionan larvas de Spodoptera exigua. Se fertilizó con fertilizante mineral a base de solución nutritiva Steiner (100%, 50%), y con biofertilizantes de lixiviado de conejo (3%) y compost de cachaza (1:1 v/v). Por medio del programa ImageJ® se calculó el área dañada de las hojas y para la dinámica de área foliar el PROC NLIN utilizando modelos logísticos. Se realizó un análisis estadístico para las variables agronómicas, oviposición y daños en espinaca usando prueba de Tukey (p≤ 0.05). Los resultados mostraron diferencias en el peso fresco de la planta (PSP) y la raíz (PFR), la mayor área foliar fue el tratamiento de compost de cachaza y solución Steiner completa SN (100%), no se observaron diferencias en los tratamientos a 45 y 60 días después de la emergencia. En cuanto a Spodoptera exigua se encontraron diferencias en el número de masas de huevos a 24 h (NMHP24), en peso de las larvas (PL), número de hojas dañadas (NHD) y área de la hoja dañada (AHD). El lixiviado de conejo puede ser una alternativa como biofertilizante para una producción orgánica en espinaca.

Longhorn beetles (Coleoptera: Cerambycidae) feed during their larval stage on wood from recently dead or diseased trees and may have a wide variety of hosts. However, reports of larval hosts for Cerambycidae could be misinterpreted from field observations. The use of freshly cut branches to attract longhorn beetles is a method that provides reliable information about which hosts they use. This study reports new records of larval hosts of longhorn beetles in the tropical dry forest of San Andres de la Cal, Morelos, Mexico. In the study area, species of woody plants were sampled, from each of which sections of branches were cut and left exposed to local field conditions for two months to attract beetles. Branches were later collected and placed in emergence chambers. A total of 26 species of Cerambycidae emerged from the branches of 51 species of woody plants of the families Apocynaceae, Araliaceae, Burseraceae, Celastraceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Juglandaceae, Malpighiaceae, Malvaceae, Moraceae, Oleaceae and Rubiaceae. For all 26 cerambycid species, we found previously unreported hosts, and for nine species, the hosts we report are the first recorded in the literature. The nine species whose host relationships have not been previously reported are: Euderces basimaculatus Giesbert & Chemsak 1997; E. pulcher (Bates, 1874); Elytroleptus grandis Linsley 1935; Neocompsa puncticollis asperula (Bates, 1885); Acanthoderes (Pardalisia) lacrymans (Thomson, 1865); Olenosus serrimanus Bates, 1872; Oreodera brailovskyi Chemsak & Noguera, 1993; O. copei McCarty, 2001 and Spliaenothecus picticornis Bates, 1880.

La J. curcas es una planta que se cultiva a nivel mundial de forma convencional, utilizando insumos artificiales, ante esta situación, es necesario generar tecnología de producción sustentable. El objetivo de esta investigación fue evaluar el efecto de biofertilizantes comerciales y enraizador químico, en variables morfológicas y de rendimiento en jatropha. El experimento se llevó a cabo en junio-diciembre de 2013, en el campo experimental de la Universidad Tecnológica de Izúcar de Matamoros (UTIM); los productos evaluados fueron: Azofer® (Azospirillum), Micorrizafer® (micorriza del género Glomus), Tricovel® (Trichoderma) y enraizador químico Rooting® (auxinas y citocininas). Se utilizó un diseño bloques completos al azar con 12 repeticiones. Resultó que el enraizador Rooting® fue el más activo, por generar el mayor número de ramas laterales, mayor número de racimos con fruto maduro, frutos maduros por planta y el peso de las semillas por planta; de los biofertilizantes, la mezcla de Azospirillum + Trichoderma, generó mayor rendimiento (número de frutos maduros por planta y peso de semilla por planta), por lo que dicha mezcla es una alternativa en la producción sustentable de jatropha.

espanolEn cualquier Universidad del Mundo, el modelo de ensenanza-aprendizajeva transformandose, respondiendo a las necesidades actuales y al desarrollomismo de la Ciencia y la Tecnologia. Ahora surgen las demandas deaprender de una manera interdisciplinaria, de lograr una cooperacion entrelas diferentes ciencias, para abrir nuestro campo de conocimiento hacia nuevoshorizontes como las formas de aprender el conocimiento de una formaintegral. Pero este cambio en el esquema de aprender el conocimiento nose realiza de una manera sencilla, porque existe una reticencia por parte delos profesores y de los alumnos a mejorar su conocimiento, porque tienenel ideal de un modelo de aprendizaje preestablecido conforme a las normasde las instituciones educativas y al modelo de produccion existente. Estosmodelos de aprendizaje de conocimiento no concuerdan con diversas ideasy pensamientos. Los alumnos tienen dos opciones, negar todo contactocon sus propias ideas o la segunda opcion, pueden realizar una defensa desus concepciones, para sufrir el rechazo o la discriminacion por sus modosde pensar. Solo nos queda un camino, y es el de fomentar la tolerancia. EnglishIn any University of the World, the teaching-learning model is transformed, responding to the current needs and the development of Science and Technology itself. Now the demands to learn in an interdisciplinary way, to achieve cooperation between the different sciences arise, to open our field of knowledge towards new horizons as the ways of learning the knowledge of an integral form. But this change in the scheme of learning knowledge is not done in a simple way, because there is reluctance on the part of teachers and students to improve their knowledge, because they have the ideal of a pre-established learning model according to the norms of educational institutions and the existing production model. These models of learning of knowledge do not agree with diverse ideas and thoughts. Students have two options, deny all contact with their own ideas or the second option, can make a defense of their conceptions, to suffer rejection or discrimination by their ways of thinking. We only have one way, and it is to promote tolerance.

"The center of origin and domestication of Jatropha curcas L. is Mexico. This crop can be affected by several phytopathogenic fungi and insect pests that diminish the quality of the seeds. The aim of this study was to evaluate the antagonistic and enthomopathogenic activity of rhizospheric bacteria (B. subtilis, B. mojavensis, B. thuringiensis and Lysinibacillus sphaericus) against Fusarium verticillioides and Leptoglossus zonatus. The antagonistic activity of rhizobacteria was evaluated against F. verticillioides by dual culture technique on potato dextrose agar. Moreover, the effect of B. thuringiensis and L. sphaericus was evaluated on the mortality and development of L. zonatus. The results demonstrated that rhizobacteria inhibited the mycelial growth (26 to 55 %) and affected the hyphal morphology of F. verticillioides regardless of the culture medium and cultivation time tested. B. mojavensis (40.4 to 54 %), L. sphaericus (39.6 to 55 %) and B. subtilis (38.5 to 50%) caused the highest percentages of inhibition. On the other hand, B. thuringiensis and L. sphaericus showed no enthomopathogenic activity because they did not affect the mortality or development of L. zonatus."

We studied the insecticidal effect of plant extracts against larvae of Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae), an important pest of Agavaceae. In the bioassays, the organic extracts of Argemone mexicana L. (Ranunculales: Papaveraceae), Allium sativum L. (Asparagales: Amaryllidaceae), Bursera grandifolia (Schltdl.) Engl. (Sapindales: Burseraceae), Chenopodium ambrosioides L. (Caryophyllales: Amaranthaceae), Prosopis laevigata (Willd.) M. C. Johnst. (Fabales: Fabaceae), and Tagetes erecta L. (Asterales: Asteraceae), which were individually incorporated into artificial diet at 500 ppm, were fed to 1st instars. The variables studied were larval, pupal, and adult weight, and larval and pupal mortality. The extracts of A. sativum, A. mexicana, P. laevigata, T. erecta, and B. grandifolia reduced larval weight by at least 50%. The greatest larval mortality was caused by the extracts of A. mexicana (53%), A. sativum (43%), and T. erecta (43%), whereas the greatest mortality of pupae was caused by extracts of T. erecta. The results suggest that A. mexicana, A. sativum, and T. erecta extracts have the greatest potential for insecticidal activity against S. acupunctatus. ResumenSe estudio el efecto insecticida de extractos vegetales en contra de larvas de Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae), plaga importante de Agavaceas. Se realizaron bioensayos de ingestion empleando individualmente los extractos organicos de Argemone mexicana L. (Ranunculales: Papaveraceae), Allium sativum L. (Asparagales: Amaryllidaceae), Bursera grandifolia (Schltdl.) Engl. (Sapindales: Burseraceae), Chenopodium ambrosioides L. (Caryophyllales: Amaranthaceae), Prosopis laevigata (Willd.) M. C. Johnst. (Fabales: Fabaceae) y Tagetes erecta L. (Asterales: Asteraceae), todos ellos a una concentracion de 500 ppm. Los extractos se incorporaron en una dieta artificial, sobre la cual se colocaron larvas del primer estadio del insecto. Las variables evaluadas fueron peso y mortalidad del insecto. Los extractos de A. sativum, A. mexicana, P. laevigata, T. erecta y B. grandifolia, inhibieron en un 50 por ciento el peso larval con respecto del testigo. Los extractos que provocaron mortalidad en larvas fueron: A. mexicana (53%), A. sativum (43%) y T. erecta (43%). Asi mismo, T. erecta fue la especie que produjo la mas alta mortalidad de pupas. Estos resultados permiten posicionar a A. sativum y a T. erecta como las especies mas promisorias con actividad bioinsecticida en contra de S. acupunctatus. View this article in BioOne

En esta investigacion evaluamos la actividad insecticida de una fraccion acuosa de tallos de Serjania schiedeana Schltdl. (Sapindaceae) (FASs), a concentraciones de 250, 500, 1,000, 1,500, y 2,000 ppm, en laboratorio e invernadero en plantas de maiz sobre larvas neonatas de Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Los resultados de los bioensayos de laboratorio mostraron que a los 14 dias el FASs a 250 y 1,500 ppm inhibio 50 y 20% el peso larval del insecto. La FASs en todas sus concentraciones ocasiono una mortalidad larval superior a 50% y una mortalidad total de larvas + pupas del 100%, excepto a 500 ppm. En el invernadero, a partir del dia siete las plantas de maiz asperjadas con FASs a 250 y 2,000 ppm disminuyeron el dano de las larvas en mas del 18%. Un perfil fitoquimico de la FASs, resulto positivo para alcaloides, flavonoides y taninos, estos compuestos podrian tener relacion con el efecto insecticida contra S. frugiperda. Los resultados demuestran que la FASs puede ser considerada para el desarrollo de nuevos insecticidas botanicos y posiblemente ser considerados en el control integrado de plagas.

En este estudio se evaluo el efecto de cuatro niveles de nitrato de potasio (KNO3: 5, 10, 15 y 20 meq L-1) en la produccion de ricinina mediante un sistema semi-hidroponico, y la actividad insecticida del extracto metanolico obtenido de hojas de Ricinus communis L contra larvas de Spodoptera frugiperda Smith. El extracto metanolico se uso para la obtencion del alcaloide, y con el se evaluo su actividad biologica contra larvas de S. frugiperda. La relacion dosis/respuesta demostro una alta correlacion positiva (R2 = 0.92, P ≤ 0.05) entre la concentracion de nitrogeno en la solucion hidroponica y el porcentaje de ricinina en las hojas. Lo mismo se observo (R2 = 0.94, P ≤ 0.05) entre el contenido de nitrogeno foliar y el porcentaje de ricinina. El uso de KNO3 como fuente nitrogenada incremento la produccion de ricinina y tambien afecto la mortalidad larval de S. frugiperda. Las LC50 determinadas para S. frugiperda fueron de 13,469.12, 15,754.34, 16,046.11 y 18,155.75 mg mL-1 para los extractos metanolicos obtenidos de hojas de plantas crecidas en las concentraciones de nitrogeno de 20, 15, 10 and 5 meq L-1 respectivamente. El incremento en la concentracion de ricinina al aumentar la concentracion de nitrogeno en la solucion hidroponica al indica que esta tecnica puede utilizarse para mejorar la produccion de este alcaloide y con ello elevar su capacidad de proteccion contra S. frugiperda

Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) (fall armyworm) is a pest native to the Americas that affects a variety of crops. Its control is based on chemical insecticides. However, this practice has been associated with changes in the susceptibility of pests to various insecticides. The use of plant products represents an eco-friendly alternative. The objective of this work was to evaluate the larvicidal activity of the chloroform extract of Senna crotalarioides (Kunth) H.S. Irwin & Barneby (Fabaceae) to control S. frugiperda. The chloroform extract of S. crotalarioides caused significant larval mortality, and reduced pupal weight and adult emergence. The analysis by gas chromatography coupled with mass spectrometry (GC-MS) revealed the presence of 22 compounds in the chloroform extract of S. crotalarioides leaves, with the straight-chain aliphatic fatty alcohol 1-octacosanol as the main component. This study revealed that the leaves of S. crotalarioides synthesize long chain alcohols, which increased the mortality of S. frugiperda in its larval stage, including the pupal stage. The extract also caused a decrease in the S. frugiperda pupal weight. The potential use of the chloroform extract obtained from S. crotalarioides and its principal chemical constituent is proposed as a promising alternative to control S. frugiperda.

The agave snout weevil Scyphophorus acupunctatus Gyllenhal (Coleoptera: Curculionidae) is an ubiquitous insect and the main pest of blue tequila agave, Agave tequilana Weber, and other agaves. This study reports the repellent effect of the hydroethanolic extract of the castor oil plant, Ricinus communis L. (Euphorbiaceae) wild and ‘Mirante’ cultivar on the adult's behavior. Females and males visited untreated agave tissue more frequently than agave tissue treated with R. communis extracts. Insects visited agaves treated with seed extracts more frequently than those with leave extracts; therefore leaves of R. communis deserve a closer look to identify their properties and gauge their potential use as a repellent.

Phyllophaga obsoleta Blanchard is a key pest in Mexican agriculture. Its chemical communication dynamics are partially known. A system of monitoring based on sex pheromones helps reduce the amount of damage it can cause as “white grubs.” To identify the sex pheromone requires many individuals, especially virgin females. Meridic diet and check diet were used to rear larvae. Both substrates were supplied with food for first- and second-instar larvae of P. obsoleta. The effect of each diet on larval survival, weight, and instar transition was evaluated. On Day 175, the meridic diet resulted in more larval weight gain and faster development into third instars than did the check diet. The meridic diet is effective for rearing P. obsoleta in a laboratory.

Bitter lupins (Lupinus spp.) are not used as a protein source because of their toxicity. However, they may have alternative uses as potential sources of natural insecticides. Quinolizidine alkaloids (QA) of three Mexican Lupinus species (Fabaceae): L. montanus (HBK), L. stipulatus (Agardh) and L. aschenbornii (Schauer), were analyzed by capillary Gas Chromatography-Mass Spectrometry. Sparteine was found in high amounts in both L. montanus and L. aschenbornii while the major alkaloids in L. stipulatus extract were aphylline and an epiaphylline-like compound. Alkaloid extracts were tested for their insecticidal activity using larvae of the Fall Armyworm, Spodoptera frugiperda (Smith); (Lepidoptera, Noctuidae) as a model pest. We compared LD50 values and mean weight of caterpillars fed with alkaloid extracts of the three species studied with those of sparteine, a widespread QA found in various lupin species. Extracts of L. montanus and L. aschenbornii were found to be as effective as sparteine and extracts L. stipulatus were found to be the most toxic against the larvae of S. frugiperda. This suggests that the various QA act differently on caterpillars, and could be used to control Spodoptera populations.

The damage caused by the fall armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) to vegetative-stage maize cultivated with chemical nitrogen fertilizers, vermicompost, and Carica papaya L. (Caricaceae) seed extract was estimated. Each shoot was infested with one first instar larva of S. frugiperda . The variables measured included the percentage of germination, length of the second and fifth leaves, stem diameter and plant height, and the estimation of damage caused by S. frugiperda larvae on maize. The results indicated that vermicompost helped seed germination on a relation 3:1 from black soil and vermicompost, the emergence was 100%, while the emergence with black soil was 80%. The ammonium sulfate increased the length of the second and fifth leaves 89.6% and 160.4% respectively, augmented the stem diameter and the plant height 290.2% and 13.3% respectively, respect to water treatment. The exogenous nitrogen sources stimulate S. frugiperda to cause more damage to the plant, the treatment urea showed 70% of damage, with phosphonitrate 62.3% and with ammonium sulfate 51.8%, when were evaluated without aqueous seed extract of C. papaya . Ammonium sulfate + aqueous extract of C. papaya seeds showed the lowest insect damage to maize with 29.6%. Se estimo el dano causado por el gusano cogollero del maiz Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) durante la etapa vegetativa de maiz cultivado con fertilizantes nitrogenados quimicos, vermicomposta, y extracto acuoso de semillas de Carica papaya L. (Caricaceae). Cada brote se infesto con una larva de primer instar de S. frugiperda . Las variables evaluadas incluyen el porcentaje de germinacion. Las variables respuesta fueron el porcentaje de emergencia, longitud de la segunda y quinta hoja, diametro de tallo y altura de la planta; asi como la estimacion de dano causado por larvas de S. frugiperda al maiz. Los resultados indicaron que la vermicomposta ayudo a la emergencia de la semilla, en una relacion 3:1 de suelo con vermicomposta alcanzo 100% de emergencia, mientras que solo con suelo, la emergencia fue de 80%; el sulfato de amonio incremento el tamano de la segunda hoja y quinta hoja 89,6 y 160,4% respectivamente, aumento el diametro de tallo y la altura de la planta 290,2 y 13,3%, respecto al tratamiento donde solo se aplico agua. Las fuentes de nitrogeno estimularon que S. frugiperda ocasionara mas dano a la planta, el tratamiento con urea presento 70% de dano, con fosfonitrato 62,3%, con sulfato de amonio fue de 51,8% sin extracto acuoso de semillas de C. papaya . El tratamiento con sulfato de amonio + extracto acuoso de semillas de C. papaya registro el menor dano del insecto al maiz con 29,6%.

Biological Activity / Caricaceae / Maize / Plant Extracts / Toxicity

Se evaluó el efecto tóxico de semillas de las variedades Mamey, Maradol, Amarilla y Hawaiana de C. papaya sobre larvas de S. frugiperda. El polvo de las semillas de C. papaya se incorporó al 10 y 15 % a una dieta artificial. Los resultados mostraron que los polvos de las cuatro variedades en sus dos concentraciones m ataron todas las larvas pero a diferente tiempo. En los tratamientos al 15 %, todas las variedades resultaron ser muy tóxicas ya que ocasionaron una mortalidad corregida de 90 % a las 72 h. Al 10 %, las variedades Mamey, Amarilla y Maradol produjeron una mortalidad corregida del 90 % a las 96 h mientras que en la var. Hawaiana fue menor al 75 % en el mismo tiempo. La mortalidad del testigo fue del 3.33%.

Mortality and growth inhibition effect of Trichiliahavanensis, Annona cherimola, and Carica papaya seed powders were evaluated on Scyphophorus acupunctatus Gyll. (Coleoptera: Curculionidae). Seeds of T. havanensis and C. papayaat 15% were very toxic to S. acupunctatus, causing 100 and 90% larval mortality. Seed powder of A. cherimola killed 63% of the weevils. All powders inhibited the weight of the insect. Annona cherimola was the most effective, decreasing the weight of larvae, pupae, and adults 98.5, 40.6, and 45.0%. These results show that T. havanensis, C. papaya, and A. cherimola seed powders have the potential to control the S. acupunctatus weevil.

The present study shows that natural products from Carica papaya can be considered as a valid alternative to control pests in agriculture. The insecticide properties of the seed extracts of four cultivars of C. papaya (Maradol, Mammee, Yellow and Hawaiian) were added to an artificial insect diet. Bioassays were conducted with hexanic, acetonic and methanolic extracts at concentrations of 10, 100 and 1000ppm. All tests were performed with the first larval stage of Spodoptera frugiperda. The response variable was insect mortality. Extracts from seeds of the Maradol, Mammee and Yellow cultivars of C. papaya, followed by extracts from seeds of the Hawaiian cultivar, applied at concentrations of 10, 100 and 1000ppm, were toxic on S. frugiperda larvae (50-70% corrected mortality rate). The acetonic extracts of the Maradol and Mammee cultivars at 10ppm were the most effective, causing mortalities of 73.6 and 62.8% of the larvae, respectively.