Sample records for termita kalotermes neotermes
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Gilberto de Freitas
1945-10-01
Full Text Available 1 O A. descreve, no presente trabalho duas novas espécies de um novo gênero de flagelados (Metasaccinobaculus, colocado entre os Oxymo-nadidae, 2 Morfológicamente, caracterizam-se pela existência de um rostelo que juntamente com o aspecto geral e as esferas endoplasmáticas os aproxima dos oximonadideos, e pela presença de um axostilo ondulante dotado de movementos enérgicos, únicos responsáveis pela locomoção do protozoário. Os flagelos foram definitivamente perdidos. 3 No seu ciclo evolutivo o protozoário apresenta duas fórmas perfeitamente distintas: uma fórma jovem que nada livremente no fluido intes¬tinal do termita e uma fórma adulta, fixa pelo rostelo na parede do tubo digestivo do hospedeiro. A forma adulta e sacciforme, com um longo rostelo em cuja extremidade anterior existe um disco de fixação. O ectoplasma é espesso sobretudo na extremidade posterior, e o endoplasma cheio de esferas pardas. O componente cinético extranuclear é constituído por um axostilo ondulante muito cromófilo, por vêzes franjados nos bordos e preso a parede do corpo por uma estrutura tubular. Além desta organela, observa-se ainda dois sistema fibrilares. O primeiro é constituído de fibras rostelares e que ligam a porção ondulante do axostilo à extremidade do rostelo. O outro que denominamos fibrilas cromófobas independentes, nascem na extremidade do rostelo, percorrendo-o lateralmente em tôda a sua extensão e atingindo o corpo, onde se resolvem em feixes secundários que se espalham em todas as direções. O núcleo é formado de traves grosseiras de cromatina, formando um re¬tículo muito irregular. A forma jovem é muito menor, com rostelo e fibrilas cromófobas rudimentares. O axostilo ondulante relativamente muito desenvolvido, se fixa na extremidade posterior. Com o crescimento, este ponto vai-se deslocando em direção à região anterior do corpo. Nota-se perto do ponto de inserção, uma bainha de filamentos fin
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Micromorfología de nidos de termitas de la República Argentina
Cosarinsky, Marcela Irene
2003-01-01
La presente contribución representa el primer estudio micromorfológico de nidos de termitas neotropicales. Incluye un análisis comparativo de la micromorfología de termiteros de diferentes especies, del nido y suelo circundante, y de los diferentes sectores del nido. Asimismo, se comparan rasgos micromorfológicos que han sido descriptos en nidos de especies de África y Australia con los observados en especies de Argentina, y se describen rasgos nuevos. Las descripciones micromorfológicas incl...
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ALIMENTARY CANAL ANATOMY AND HISTOLOGY OF THE WORKER TERMITE NEOTERMES BOSEI
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LEKSONO EKOPURANTO HARIPRABOWO
2006-01-01
Full Text Available As social insects, termites live in a colony that consist of reproductive (drone and queen, and non-reproductive (soldiers and workers castes. Workers obtain their food directly from wood, humus, and other substances that contain cellulose. The objective of this study was to examine the alimentary canal of the Neotermes bosei workers. Observations of gut transverse section were carried out through the length, perimeter, and area of each alimentary canal region. The results showed that total length of N. bosei alimentary canal was 13.71+1.28 mm. The canal was divided into fore-, mid-, and hindgut which were 24, 28, and 48%, respectively of the gut total length. Two types of alimentary canal epithelial cells were found, i.e. the squamous and transitional cells. Areas covered with thick muscular tissues were crop, proventriculus, and rectum. Proventriculus was characterized with six large dentitions. There was no gastric caeca in N. bosei midgut, which commonly occurred in chewing insect. Secretory cells .wer e observed at proventriculus and ventriculus regions. Cardiac valve was found at the anterior end of ventriculus. Area with the largest outer perimeter was the rectum pouch. Enteric valve had three internal folds.
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The first report of gynandromorphy in termites (Isoptera; Kalotermitidae; Neotermes koshunensis)
Miyaguni, Yasushi; Nozaki, Tomonari; Yashiro, Toshihisa
2017-08-01
This is the first report of gynandromorphy in Isoptera. An Asian dry-wood termite, Neotermes koshunensis (Shiraki) [Kalotermitidae], possessing both male and female phenotypic characteristics, was found on Okinawa Island, Japan. This deformed individual showed morphological and anatomical hermaphroditism in the abdomen. The right side of the seventh sternite was the female form and contained an ovary, while the left side was the male form and contained a testis. Genotypic analysis revealed that this individual was a genotypic bilateral chimera. These results suggested that the termite was a bilateral gynandromorph with a male left side and a female right side. As reported previously in other insects, double fertilization (by two sperms, one with an X and one with a Y chromosome) of a binucleate egg is the most likely mechanism that generated this genotypic bilateral chimera. N. koshunensis has the ability to reproduce through parthenogenesis, in which the secondary polar body is likely to be used for nuclear phase recovery. If the second polar body in this mechanism has high fertility and healthy embryogenic potential, like an egg nucleus, some of gynandromorphs might be produced by a side effect of parthenogenetic ability.
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Cecilia Lara Mantilla
2013-06-01
Full Text Available Título corto: Bacterias celulolíticas aisladas del intestino de termitas (Nasutitermes nigriceps Título en ingles: Cellulolytic bacteria isolated from termites’ gut (Nasutitermes nigriceps with probiotic characteristics and potential pasture degradationResumen: El objetivo de la presente investigación fue aislar bacterias celulolíticas del intestino de termitas (Nasutitermes nigriceps para determinar sus propiedades probióticas in vitro y su potencial en la degradación de pasto. Las termitas fueron tratadas con detergente antibacterial, separando y macerando luego, el intestino de las mismas en agua peptonada estéril. Diluciones de esta mezcla fueron inoculadas en cajas Petri con medio Luria Bertani (LB y Carboximetilcelulosa (CMC al 2%, incubando a 37º C por 24 horas, para luego revelar con Rojo Congo al 1%. Las bacterias que presentaron mayores halos de degradación fueron sometidas a tinción de Gram y a pruebas probióticas de temperatura, pH, salinidad y presencia de sales biliares, así como también a pruebas de antagonismo y degradación de pasto. Los resultados revelaron la presencia de 9 bacilos celulolíticos Gram (- de los cuales, los bacilos BTN7 y BTN8, presentaron los mejores halos de degradación, 12 y 14 mm de diámetro respectivamente, creciendo adecuadamente en las diferentes pruebas probióticas con densidades entre 106 y 108 UFC/ml; el porcentaje de degradación de materia seca fue de 39.73% y 36.10% en 48 y 72 horas respectivamente. Las pruebas bioquímicas API E (bioMérieux SA revelaron que los bacilos BTN7 y BTN8 pertenecen al género Enterobacter sp. Los anteriores resultados abren la posibilidad de emplear, estos microorganismos como aditivos en la alimentación de rumiantes, a fin de contribuir con un mayor aprovechamiento de pastos, y otros sustratos vegetales lignocelulósicos.Palabras claves: Probióticos, Maralfalfa (Pennisetum sp., microorganismos ruminales, lignocelulosa, Enterobacter
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Uchima, Cristiane Akemi; Tokuda, Gaku; Watanabe, Hirofumi; Kitamoto, Katsuhiko; Arioka, Manabu
2011-03-01
Neotermes koshunensis is a lower termite that secretes endogenous β-glucosidase in the salivary glands. This β-glucosidase (G1NkBG) was successfully expressed in Aspergillus oryzae. G1NkBG was purified to homogeneity from the culture supernatant through ammonium sulfate precipitation and anion exchange, hydrophobic, and gel filtration chromatographies with a 48-fold increase in purity. The molecular mass of the native enzyme appeared as a single band at 60 kDa after gel filtration analysis, indicating that G1NkBG is a monomeric protein. Maximum activity was observed at 50 °C with an optimum pH at 5.0. G1NkBG retained 80% of its maximum activity at temperatures up to 45 °C and lost its activity at temperatures above 55 °C. The enzyme was stable from pH 5.0 to 9.0. G1NkBG was most active towards laminaribiose and p-nitrophenyl-β-D-fucopyranoside. Cellobiose, as well as cello-oligosaccharides, was also well hydrolyzed. The enzyme activity was slightly stimulated by Mn(2+) and glycerol. The K(m) and V(max) values were 0.77 mM and 16 U/mg, respectively, against p-nitrophenyl-β-D-glucopyranoside. An unusual finding was that G1NkBG was stimulated by 1.3-fold when glucose was present in the reaction mixture at a concentration of 200 mM. These characteristics, particularly the stimulation of enzyme activity by glucose, make G1NkBG of great interest for biotechnological applications, especially for bioethanol production.
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Pillotinas and hollandinas: distribution and behaviour of large spirochaetes symbiotic in termites.
To, L; Margulis, L; Cheung, A T
1978-01-01
Pillotina spirochaetes have been observed in the hindguts of wood-eating cockroaches (Cryptocercus punctulatus), and in 25 out of 28 species of termites examined. They were especially abundant in 21 species of dry wood termites of the family Kalotermitidae, from Europe, North America and Australia. These included many species of Kalotermes and one or a few of the following: Glyptotermes, Bifidotermes, Neotermes, Ceratokalotermes, Paraneotermes, Cryptotermes, Porotermes, Marginitermes, Pterotermes, Zootermopsis, Reticulitermes, Coptotermes, Heterotermes, and nasutitermitids. Identifications of pillotinas were made on the basis of large size (0.5--2 micromtere in diameter, 50 to greater than 100 micrometers in length) and wave pattern; these were verified by electron microscopy in K. schwarzi, Pterotermes occidentis and others. Pillotinas were also present in all species of subterranean termites (Family Rhinotermitidae) examined, and in the most primitive Australian termite, Mastotermes darwiniensis (Family Mastotermitidae). They were not observed in damp wood termites (Family Hodotermidiae). Pillotinas are invariably associated with a rich, complex xylophagous microbial community composed primarily of motile prokaryotes, and hypermastigote and polymastigote flagellates. Some have been previously described by those primarily concerned with termite hindgut protozoa. Observations were made on their modes of behaviour, division, and microbial associates. A new genus of spirochaetes, Hollandina, is also described. It is distinguished from Pillotina by a smaller size and several ultrastructural features, but is otherwise closely related taxonomically. Evidence is provided to support Hollande and Gharagozlou's (1967) concept that the pillotinas and hollandinas deserve the taxonomic status of 'family' and that they should be classified with the cristispire siprochaetes a-cording to the scheme developed by Hovind-Hougen (1976). Spirochaetes are treated as a Phylum of the
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Chouvenc , Thomas; Su , Nan-Yao; Robert , Alain
2009-01-01
Seven termite species (Isoptera) from five families were tested for disease susceptibility against the entomopathogenic fungus Metarhizium anisopliae using a standard protocol: Mastotermes darwiniensis (Mastotermitidae), Hodotermopsis sjoestedti (Termopsidae), Hodotermes mossambicus (Hodotermitidae), Kalotermes flavicollis (Kalotermitidae), Reticulitermes flavipes and Prorhinotermes canalifrons (Rhinotermitidae), and Nasutitermes voeltzkowi (Termitidae). Our results showed a large diversity i...
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Víctor Hugo Serrano-Cardozo
2008-12-01
Full Text Available Ecology, morphology, and phylogeny contribute to the organization of lizard assemblages; however, the number of lizard assemblages for which detailed knowledge of closely related sympatric species is available is limited. We studied the diet of 3 sympatric species of lizards (Sceloporus gadoviae, S. horridus, and S. jalapae from arid tropical scrub forest in Puebla, Mexico. These species prey primarily on arthropods, mostly termites, ants, and beetles. Spring and summer rains caused an increase in available prey biomass. However, lizards continued using the same resources throughout the study. These 3 species of Sceloporus are similar in their diet, especially the smaller bodied species, S. gadoviae and S. jalapae. Termites are a very important food for the 3 species throughout the year and are a major resource during the rainy season, which is not consistent with the hypothesis that many lizards eat termites only in the dry season.La ecología, morfología y la filogenia contribuyen a la organización de los ensambles de lagartijas. Sin embargo, son pocos los estudios detallados sobre la organización de estos ensambles y más aún, con especies simpátridas. Estudiamos la dieta, reproducción y dimorfismo sexual de 3 especies simpátridas de lagartijas (Sceloporus gadoviae, S. horridus, and S. jalapae de un matorral árido tropical en Puebla, México. Estas especies se alimentaron de artrópodos; principalmente de termitas, hormigas y escarabajos. Las lluvias de primavera y verano causaron un incremento en la biomasa de presas; sin embargo, las lagartijas continuaron usando los mismos recursos. Las lagartijas fueron especialistas consumiendo presas en relación a su abundancia. Las 3 especies fueron similares en su dieta, especialmente las especies pequeñas S. gadoviae y S. jalapae. Las termitas son un importante recurso para estas 3 especies durante el todo año y la principal fuente alimenticia en la estación lluviosa, lo cual no es
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Laura Martínez-Tabche; Martha Romero Solís; Eugenia López López; Marcela Galar Martínez
1999-01-01
Actualmente en México son empleados los plaguicidas diclorodifeniltricloroetano (DDT) y clordano (CLO) para combatir la malaria y termitas. De 1990 a 1996 un total de 27 ton de DDT y 508 de CLO, en forma de productos técnicos, fueron importados. El objetivo de este estudio fue establecer una metodología para determinar el impacto ambiental que pueden producir estos compuestos sobre un embalse. El efecto tóxico del DDT y CLO fue evaluado sobre la actividad de la o-demetilasa (OD) y del acetilc...
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Energy Technology Data Exchange (ETDEWEB)
Abt, Birte; Han, Cliff; Scheuner, Carmen; Lu, Megan; Lapidus, Alla; Nolan, Matt; Lucas, Susan; Hammon, Nancy; Deshpande, Shweta; Cheng, Jan-Fang; Tapia, Roxane; Goodwin, Lynne; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, Natalia; Mavromatis, Konstantinos; Mikhailova, Natalia; Huntemann, Marcel; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Brambilla, Evelyne-Marie; Rohde, Manfred; Spring, Stefan; Gronow, Sabine; Goker, Markus; Woyke, Tanja; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C.; Klenk, Hans-Peter; Detter, John C.
2012-05-25
Spirochaeta coccoides Dröge et al. 2006 is a member of the genus Spirochaeta Ehrenberg 1835, one of the oldest named genera within the Bacteria. S. coccoides is an obligately anaerobic, Gram-negative, non-motile, spherical bacterium that was isolated from the hindgut contents of the termite Neotermes castaneus. The species is of interest because it may play an important role in the digestion of breakdown products from cellulose and hemicellulose in the termite gut. Here we provide a taxonomic re-evaluation for strain SPN1T, and based on physiological and genomic characteristics, we propose its reclassification as a novel species in the genus Sphaerochaeta, a recently published sister group of the Spirochaeta. The 2,227,296 bp long genome of strain SPN1T with its 1,866 protein-coding and 58 RNA genes is a part of the GenomicEncyclopedia of Bacteria and Archaea project.
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Energy Technology Data Exchange (ETDEWEB)
Yorio, Daniel; Cincotta, Daniel O; Camacho, Esteban F; Bruno, Hernan R; Boero, Norma L [Comision Nacional de Energia Atomica, General San Martin (Argentina). Centro Atomico Constituyentes
1999-07-01
The mixture of Al-U{sub 3}O{sub 8} is not in a state of chemical equilibrium, and at temperatures of between 850 degree C and 1000 degree C, it reacts exo thermally. This is known, in corresponding bibliography, as a 'Thermite reaction'. This mixture is used in the manufacturing of the plate-type fuel used in research reactors. It has been pointed out that the release of energy caused by this type of reactions might represent a risk in case of accidents in this type of reactor. Conclusions, in general, tend to indicate that no such risk exists, although no concrete assurance is given that this is the case, and this fact, therefore, leaves room for doubt. The objective of this paper is to provide an in-depth study of what happens to a fuel plate when it is subjected to thermite reaction. We will, furthermore, analyze the consequences of the release of energy generated by this type of reaction within the core of the reactor, clearly defining the problem for this type of fuel and this kind of reactor.
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Energy Technology Data Exchange (ETDEWEB)
Gosswald, K.; Kloft, W. [Institute of Applied Zoology, University of Wurzburg, Federal Republic of Germany (Germany)
1963-09-15
One of the most important aspects of social insects, such as ants, honey-bees and termites, is their tendency to trophallactic food exchanges, which can be studied well by the use of labelled food. In comparative studies we found the most rapid rate of exchange in honey-bees, but extreme differences were observed among the different sub-families of ants, which must be taken in consideration in case of tracer field-experiments. The greatest tendency towards trophallactic exchanges was found in the sub-family Camponotinae. Ants of the genus Formica, especially Formica polyctena Foerst, and related polygenous and polycalous species known to be imoortant factors in die preventive biological control of forest insect pests, were intensively analysed. It was found that the rate of food exchange within one nest is conditioned by temperature, time, number of individuals and saturation. Another question is whether food exchanges also take place between the different nests of ant-colonies of the same species. By labelling single nests with radioactive food we were able to find intensive food exchanges with different nests in the colony, up to distances of 200 m. We obtained similar results in three different colonies and in different years. The existence of such long-range food exchanges is very important for the estimation of the regulating effect on insect pests of useful Formica species, since these exchanges prevent die quick saturation of any nest through local mass-infestation of insects in their predating area. It was shown bv the tracer experiments that the collected food flows in most of the surrounding nests of the ant-colony: thus colonies of those useful wood-ants act as a complex system with high ecological effectiveness. Using labelled food, we studied in termites (Kalotermes flavicollis Fabr.) which stages and castes are capable of direct feeding or are receptors of stomodeally or proctodeally given trophallactic food. Pseudoworkers are most effective. We also
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Análisis cualitativo y cuantitativo de árboles urbanos de un barrio de Bauru, São Paulo, Brasil
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Renan Borgiani
2016-12-01
Full Text Available El rápido crecimiento de las ciudades ha dado lugar a varios problemas ambientales. Buscando minimizar estos problemas, la arborización en el medio urbano pasó a ser indispensable y se considera un parámetro de calidad de vida de la población. En este contexto, el presente estudio tuvo como objetivo diagnosticar la situación de la arborización urbana en el barrio Jardín Brasil en Bauru, São Paulo, Brasil, a través de un levantamiento cualitativo y cuantitativo de las especies arbóreas presentes. Fue posible registrar 23 familias y 41 especies en un total de 510 individuos de los cuales 11 estaban muertos. El barrio tiene una diversidad relativamente baja y la mayoría de las especies encontradas son exóticas (60,98%. Las especies más comunes son: Licania tomentosa (31,87%, Caesalpinia peltophoroides (11,16%, Lagerstroemia indica (9,56%, Murraya paniculata (6,57% y Terminalia catappa (5,98%. Gran parte de los problemas encontrados son el resultado de no planificar la silvicultura urbana, lo que termina generando conflicto con el cableado eléctrico y la construcción. Entre tanto, fueron pocos los casos de conflictos con el alumbrado público y las señales de tránsito. Se destacó también el gran número de individuos arbóreos atacados por termitas y hormigas (59,34%. Investigaciones como ésta son útiles para la toma de decisiones y la planificación de los árboles urbanos de una ciudad.
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Sergio Alberto Curti-Díaz
2012-01-01
Full Text Available Veracruz, México, contaba con 36,166.36 ha plantadas con limón ‘Persa’ (Citrus latifolia Tan. en 2010, que produjeron 437,460.80 toneladas de fruta con un valor de 1,196.9 millones de pesos. Dado que los portainjertos influyen en el desarrollo vegetativo, producción y calidad de los frutos cítricos, en función de la especie de portainjerto, tipo de suelo y clima donde se cultiven, se comparó el comportamiento agronómico del limón ‘Persa’ de 11 años de edad, injertado en citrange Carrizo, citrumelo Swingle y en los limones Volkameriana y Rugoso, plantado a 4 x 6 m, en un suelo arcilloso, delgado y fuertemente ácido (pH 4.5. Se registraron las dimensiones del árbol, producción, eficiencia productiva y calidad de fruta de ocho cosechas, durante junio de 2008 a julio de 2009. Se obtuvieron los siguientes resultados relevantes: a Carrizo, Swingle y Volkameriana indujeron menor altura y volumen de copa que Rugoso, pero la conformación de copa del limón ‘Persa’ fue más ancha que alta, con todos ellos, b El rendimiento de fruta por árbol fue mayor con Rugoso, pero su eficiencia productiva igualó a la obtenida con Carrizo y Swingle, c Carrizo, Rugoso y Swingle indujeron mayor volumen de fruta con calidad de exportación (Estados Unidos, sin presentar diferencias entre ellos en cuanto a los calibres comerciales de la fruta producida, y d El comportamiento agronómico de Carrizo y Swingle, en cuanto a vigor, porte, eficiencia productiva, calidad de fruta y tolerancia a las termitas, ofrece mayores ventajas para cultivar limón ‘Persa’ en suelos de sabana.
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Vertical Distribution of Termites on Trees in Two Forest Landscapes in Taiwan.
Li, Hou-Feng; Yeh, Hsin-Ting; Chiu, Chun-I; Kuo, Chih-Yu; Tsai, Ming-Jer
2016-03-25
Termites are a key functional group in the forest ecosystem, but they damage trees. To investigate the termite infestation pattern on the whole tree, we cut 108 blackboard trees,Alstonia scholaris(L.) R. Br., and 50 Japanese cedars,Cryptomeria japonica (L. f.) D. Don, into sections. The bark surface and cross sections of the tree trunk were examined along the axes. A high percentage of blackboard trees (92.6%) was infested by fungus-growing termites,Odontotermes formosanus(Shiraki), but damage was limited to the bark surface at a 2-m height. The infestation rate of dampwood termites,Neotermes koshunensis(Shiraki), was only 4.6% (5/108), and all infestations were associated with trunk wounds.N. koshunensiswas found at significantly higher portion of a tree thanO. formosanus Among 50 Japanese cedars, 20 living trees were not infested by any termites, but 26 of the 30 dead trees were infested by subterranean termites,Reticulitermes flaviceps(Oshima), which excavated tunnels in the trunk. The infestation rate at basal sections was higher than that at distal sections. Only one Japanese cedar tree was infested by another dampwood termite,Glyptotermes satsumensis(Matsumura). The two dominant termite species,O. formosanusandR. flaviceps, had subterranean nests and infested trees from bottom up. The two primitive termitesN. koshunensis andG. satsumensishad low infestation rates and are most likely to infest trees by alates from top down. The niche segregation in trees of three termite families, Kalotermitidae, Rhinotermitidae, and Termitidae, was distinct. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Cecilia Lara Mantilla
2013-01-01
Abstract: The objective of this research was to isolate cellulolytic bacteria from the gut of termites (Nasutitermes nigriceps to determine their probiotic properties in vitro and its potential in degrading grass. Termites were treated with antibacterial detergent, then their intestine was separated and macerated in sterile peptone water. Dilutions of this mixture were inoculated in Petri dishes using Luria Bertani (LB method and carboxymethylcellulose (CMC 2%, incubated at 37 ° C for 24 hours, and then revealed with 1% Congo Red. Bacteria with higher degradation halos were subjected to Gram staining and probiotic temperature tests, pH, salinity and the presence of bile salts, as well as antagonism and degradation of grass tests. The results revealed the presence of 9 Gram (- cellulolytic bacillifrom which the bacilli BTN7 and BTN8, showed the best degradation halosof 12 and 14 mm in diameter respectively, growing suitably in the different probiotic tests with densities between 106 and 108 CFU / ml, the degradation percentages of dry matter was 39.73% and 36.10% within 48 and 72 hours respectively. Biochemical tests API E showed that (bioMérieux SA bacilli BTN8 and BTN7 belong to the genus Enterobacter sp. The above mentioned results open the possibility of using these organisms as additives for ruminants feeding, in order to contribute to a better use of pasture, and other lignocellulosic vegetal substrates. Key words:Probiotics, Maralfalfa (Pennisetum sp., ruminal microbes, lignocellulose, Enterobacter.
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Georgina Erra
2016-01-01
Full Text Available En esta contribución se da a conocer el primer registro de termiteros fósiles para la región Mesopotámica de Argentina, y su disposición espacial, al tiempo que se discuten sus afinidades taxonómicas e implicancias paleoambientales. Las estructuras fósiles pertenecen a nidificaciones de insectos sociales atribuibles a miembros de la Familia Termitidae, y se ubican en la zona de contacto entre la base de la Fm. Toropí/Yupoí (Pleistoceno tardío y el tope de la Fm. Ituzaingó (Mioceno tardío-Plioceno. Se las identifica en los alrededores del Arroyo Toropí (28°36’ S y 59°02’ W, Departamento Bella Vista, provincia de Corrientes. El estudio de las nidificaciones y su disposición espacial se realizó en cinco campos de termiteros mediante su relevamiento y descripción morfológica. La morfología de las estructuras estudiadas coincide claramente con la de los nidos de termitas, en donde resulta característica una fuerte muralla externa. La caracterización de campo, yacencia, desarrollo, frecuencia, tamaños e interrelaciones de los termiteros fósiles y actuales sugieren una estrecha similitud con montículos del género Cornitermes. La morfología presente muestra también cierta semejanza con Tacuruichnus farinai, descripta para el Piso/Edad Marplatense (Plioceno de la región Pampeana. Por otro lado, el análisis fitolítico indicó que las cantidades y las morfologías fitolíticas son semejantes tanto en los termiteros actuales como en los fósiles. Desde un punto de vista paleoambiental, la abundancia de estos termiteros en el contacto entre las mencionadas unidades indicaría la existencia de suelos bien desarrollados, con abundante vegetación graminosa y condiciones húmedas y cálidas con estacionalidad marcada.
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Laura Martínez-Tabche
1999-12-01
Full Text Available Actualmente en México son empleados los plaguicidas diclorodifeniltricloroetano (DDT y clordano (CLO para combatir la malaria y termitas. De 1990 a 1996 un total de 27 ton de DDT y 508 de CLO, en forma de productos técnicos, fueron importados. El objetivo de este estudio fue establecer una metodología para determinar el impacto ambiental que pueden producir estos compuestos sobre un embalse. El efecto tóxico del DDT y CLO fue evaluado sobre la actividad de la o-demetilasa (OD y del acetilcolinesterasa (AchA del cladócero Daphnia magna al exponerla a diferentes concentraciones de los insecticidas disueltos en el agua de tres sitios de la presa Ignacio Ramírez (PIR. El efecto del agua contaminada con los insecticidas sobre la actividad de la AChA y OD, así como la CL50, fueron utilizadas como indicadores de exposición para determinar los lugares más contaminadas de la PIR. Las características fisicoquímicas del agua así como la biodiversidad de los sitios en estudio de la presa fueron considerados. Los resultados obtenidos demuestran que la estación cercana a la compuerta exhibe un potencial de toxicidad, ya que las actividades enzimáticas fueron modificadas. Se sugiere utilizar las actividades de AchA y OD del cladócero para evaluar la toxicidad de un cuerpo de agua contaminado por insecticidas organoclorados.Chlorodiphenylnitrichloroethane (DDT and chlordane (CLO are currently used in Mexico to control malaria and termites. From 1990 to 1996 a total of 27 ton of DDT and 508 of CLO were imported. We establish a methodology to determine their environmental impact in a Mexican dam (Ignacio Ramírez. The toxic effect of DDT and CLO were evaluated on the o-demethylase (OD and acethycholinesterase activities (AchA of the cladoceran Daphnia magna exposed to different concentrations of the insecticides solved in water from three sites. Their effect on the AchA and OD activities, and so the CL50 were used as exposure bioindicators to
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Madang A Dasbak
2012-03-01
maíz (Zea mays L., de polinización abierta e híbrido en cultivos regulares por 2 anos (2005-2006 seguido por un ratoon por 1 ano (2007. Termitas (Odontotermes badius, grillos (Gymnogryllus lucens y saltamontes variegado (Zonocerus variegatus fueron las plagas de plántula del cultivo, causando dano mínimo. Infestaciones con Clavigralla spp. fueron altas en el estado reproductivo causando 24% y 29% de dano seminal en cultivos regular y de poroto gandul ratoon. El maíz suprimió la incidencia de la plaga y el dano a las vainas y semillas de poroto gandul pero redujeron significativamente (P < 0,01 el rendimiento de grano en los cultivos de poroto gandul en 2005 y 2006, pero no en ratoon en 2007. Los genotipos de poroto gandul difirieron significativamente (P < 0,05 en incidencia de la plaga al estado de vaina en cultivos regular y ratoon y en rendimiento de grano (P < 0,01 bajo el cultivo regular. El rendimiento de granos de los cultivos de poroto gandul ratoon fue aproximadamente 60% de aquel del cultivo regular. Los genotipos ICPL 161 e ICPL 87 se recomendaron para adopción por los agricultores basados en tolerancia a las plagas y alto rendimiento de granos o como idiotipos en programas de hibridación de poroto gandul.