Tetramorium notomelanum sp. n. is described from the Tehuacán Valley, state of Puebla, México. Its distribution and relation with other species of the tortuosum-group is discussed. The new species of Tetramonium is described from workers, and distinguished from others of the group by several characters: i) black coloration of the body; ii) size: T. notomelanum sp. n. is smaller than T. hispidum (Wheeler), T. mexicanum Bolton and T.spinosum (Pergande), but larger than T. bicolorum Vásquez-Bolaños and T. placidum Bolton; iii) length of the hairs of the dorsal of the head are equal to the diameter of eye; iv) the length of the hairs on the scape and tibiae less than the width of the appendage where they are located. This is the second species of the tortuosum group of Tetramorium found in the State of Puebla, and the fourth recorded in Mexico.

Los colémbolos son fragmentadores importantes de la hojarasca, presentan diferentes patrones de distribución a lo largo de un gradiente altitudinal. El objetivo del presente trabajo es determinar la diversidad y distribución de Collembola en el volcán Iztaccíhuatl. Para ello, se realizaron cuatro muestreos, a lo largo de un año en cuatro pisos altitudinales (I=2 753, II=3 015, III=3 250 y IV=3 687m.s.n.m.) y se calcularon los índices de diversidad de Shannon, equitatividad de Pielou y dominancia de Simpson, para compararlos mediante una prueba de t modificada. Los resultados muestran al piso III como el más diverso, y la mayor equitatividad se encuentra en el II. Además, se hallaron diferencias significativas entre los pisos II-III (t0.01, 187=4.11, p<0.05) y entre III-IV (t0.01, 187=3.8, p<0.05). Para las fechas de recolección no obtuvimos diferencias significativas (t0.01, 187=2.71, p<0.05). Al final encontramos que la temporalidad no incrementa la diversidad (estadísticamente), por consiguiente, condiciones como la altitud, vegetación y heterogeneidad geográfica crean microambientes, para protegerse de inclemencias ambientales. El piso I es el más homogéneo, seguida por el II y el III, además hallamos que los sitios más diversos son aquellos de pendientes menos pronunciadas.

Distribution and diversity of springtails (Hexapoda: Collembola) on the altitudinal gradient of a temperate forest in Mexico. Mountain ecosystems have shown slow mineralization activity due to weather conditions, and to some groups with arthropods with special roles. The Collembola is an important group for litter fragmentation, showing different distribution patterns. The objective of the present study was to determine the diversity of Collembola along a volcano altitudinal gradient. For this, four sampling expeditions evaluated four altitudinal levels (I=2 753, II=3 015, III=3 250 and IV=3 687 masl) in Iztaccihuatl Volcano, from November 2003, and March, June and August 2004. Shannon diversity (H’), Pielou evenness (J’) and Simpson dominance (1/λ) indices were calculated. The similarity between the associations of springtails between the sampling sites was evaluated by a cluster analysis using the Pearson correlation coefficient, as distance and the unpaired arithmetic averages (UPGMA) as amalgamation method. A total of 24 075 springtails, distributed in 12 families, 46 genera and 86 species was collected. The higher species abundance was found at the altitudinal area II. The lowest diversity value was recorded in IV, while the higher diversity values were found in III. Significant differences between Shannon indices were found between zones II-III (t0.01, 187=4.11, p<0.05) and between III-IV (t0.01, 187=3.8, p<0.05) according to modified t-test. When considering sampling dates, no significant differences were found. The dendrogram showed that in composition the level I is more homogeneous throughout the year. In conclusion, a statistically significant seasonal variation in springtail abundances was not found, but it was observed that, the lower altitude (I) resulted more homogeneous along the studied period, followed by level II and III. There is a particular assemblage of springtails community in each altitudinal area studied; in general, the sites with low slope resulted more diverse in Collembola communities. These results show that there are important factors such as altitude, vegetation type and microhabitat heterogeneity that may affect the distribution of springtails communities along an altitudinal gradient. Rev. Biol. Trop. 59 (1): 315-327. Epub 2011 March 01.

Se describen y comparan los patrones de abundancia de colémbolos de hojarasca y suelo de dos cuencas hidrológicas de la Estació n de Biología Chamela (EBCh, UNAM) en Jalisco, México, con base en colectas mensuales durante un año. Esta localidad, donde el tipo de vegetación dominante es la selva baja caducifolia, presentó un año de precipitación pluvial atípico durante los muestreos realizados, con la mayor cantidad de lluvia durante enero. El muestreo de ambos biotopos fue aleatorio, los núcleos fueron de igual tamaño (95 cm²) y se procesaron in situ mediante embudos de Berlese. Adicionalmente, se cuantificaron diferentes variables edáficas. Se analizó el efecto de los factores cuenca, biotopo y estacionalidad sobre la abundancia de las familias de Collembola. Mediante análisis de conglomerados (AC) se exploran las relaciones faunísticas entre los ensamblajes, y mediante análisis de correspondencia canónica (ACC), las relaciones entre los ensamblajes y las variables fisicoquímicas del suelo. Se obtuvieron 24.253 colémbolos pertenecientes a trece familias. Las más abundantes fueron Isotomidae, Entomobryidae, Hypogastruridae y Sminthuridae. El AC mostró mayor similitud entre biotopos que entre cuencas, mientras que en el ACC la variable más importante para explicar la distribución y abundancia de los Collembola fue la humedad.

The abundance patterns of leaf litter and soil springtails (Hexapoda: Collembola) from two hydrological watersheds of the Chamela Biological Statión (EBCh, UNAM) in Jalisco, México are described and compared based on monthly sampling over one year. This locality, where the dominant vegetatión is tropical dry forest, had an atypically high rainfall during the sampling period, with the greatest amount of rain during January. Sampling in both biotopes was random, the areas sampled were of the same size (95 cm²), and these were processed in situ using Berlese funnels. In addition, different edaphic characteristics were quantified. The effect of watershed, biotope and seasonality factors on the abundance of Collembola families was analysed. Using Cluster Analysis (CA), the faunistic relationships between the assemblages were explored, and using Canonical Correspondence Analysis (CCA) the relationships between assemblages and the physico-chemical variables of the soil. A total of 24.253 Collembola were obtained, belonging to 13 families. The most abundant were Isotomidae, Entomobryidae, Hypogastruridae and Sminthuridae. The CA showed more similarity between biotopes than between hydrological watersheds, while in the CCA the most important variable to explain the distributión and abundance of the Collembola was humidity.

En respuesta a la necesidad de dar valor agregado a la leche producida en los municipios de Salamina, Aranzazu y Viterbo, del departamento de Caldas, se formuló un proyecto con el objetivo general de desarrollar quesos madurados con destino a los mercados nacional e internacional. Para ello, inicialmente se realizó un estudio de caracterización físico-química de la leche cruda proveniente de esos municipios, encontrándose que los estándares de calidad como densidad (1.030-1.033 g/l), extracto seco total (11.30%), y extracto seco desengrasado (8,30%) de la leche de los dos primeros se hallan en el rango considerado normal para la elaboración de quesos. Posteriormente, se desarrollaron los procesos productivos de los quesos Cammembert, Cheddar, Emmental, Gruyere y Gouda, en la Unidad Tecnológica de alimentos, de la Universidad de Caldas, bajo un diseño experimental de preexperimento con una sola medición y utilizando las técnicas validadas actualmente para su elaboración; dichos procesos fueron analizados con las características sensoriales y la evolución de los fenómenos de maduración (cambios de proteólisis y lipólisis). Entre los resultados obtenidos se destaca la estandarización de los procesos para quesos Cammembert, Cheddar y Gouda, que alcanzaron las mayores preferencias sensoriales y una maduración óptima verificada mediante parámetros como grado de acidez, grado de maduración, acidez, porcentaje de proteína y humedad. De esta manera se pudo comprobar que es factible desarrollar algunos quesos madurados con leches procedentes de los municipios del norte de Caldas y transferir los resultados a sus centros de acopio para darle un mayor valor agregado a la producción de leche cruda a nivel semiindustrial.

Responding to the need to provide added value to milk produced in the towns of Salamis, Aranzazu and Viterbo in the Caldas department, a project was formulated with the overall objective of developing the production of ripened cheeses destined for domestic and international markets. The physicochemical characteristics of raw milk from these municipalities were thus studied initially, finding that standards regarding milk quality and density (1.030-1.033 g / l), total dry extract (11.30%) and defatted dry extract (8.30%) for the first two came within the range considered normal for cheese-making. Subsequently, Camembert, Cheddar, Emmental, Gruyere and Gouda cheese-making processes were developed in the University of Caldas' Food Technology Unit, using an preexperimental design having a single measurement and using techniques currently validated for ripened cheese preparation. Such processes were analysed for the sensory characteristics and evolution involved in ripening (proteolysis and lipolysis changes). Standardising Camembert, Cheddar and Gouda cheese production should be stressed among the results as they eventually complied with the highest sensory preferences and optimum ripening as verified by parameters such as degree of acidity, ripeness and protein and moisture percentage. It was thus found feasible to develop some ripened cheeses from milk produced in the northern municipalities of Caldas and transfer the results to its collection centres for providing greater added value to raw milk production at semiindustrial level.

Se presentan datos sobre la estructura de la comunidad de colémbolos en musgos corticícolas, de un bosque de encino y abetos en la vertiente NW del Volcán Iztaccíhuatl, Estado de México, México. El estudio comprendió cuatro muestreos (noviembre de 2003, marzo, junio y agosto de 2004), realizados en tres altitudes I: 2 750 m; II: 2 930 m y III: 3 350 m snm. En cada altitud, se calculó la riqueza de especies (S), los índices de diversidad de Shannon (H’), Equitatividad de Pielou (J’) y, dominancia de Simpson (<IMG SRC="/img/revistas/rbt/v56n2/signo3.jpg" WIDTH=20 HEIGHT=14>). Se utilizó un análisis de varianza de dos vías (ANOVA) para evaluar el efecto de la altitud y fecha de muestreo, sobre la densidad total de los colémbolos. El número total de especies fue de 24, variando de 13 para la altitud mayor a 17 en la menor. La mayor densidad se encontró a mayor altitud. Americabrya arida y Willowsia mexicana fueron las especies dominantes, y se encontró un efecto positivo significativo de la altitud sobre sus densidades. La mayor similitud entre comunidades de acuerdo con el índice de Sörensen se presentó entre las altitudes II y III, con un 59%.

Structure of the Collembolan community (Hexapoda: Collembola) in bark mosses along an altitudinal gradient of a subhumid forest in Mexico. The structure of the community of moss springtails on oak and fir bark in the forests at the NW slope of iztaccíhuatl Volcano, State of Mexico, is analyzed. The study included four samplings (November 2003, March-June-August 2004), carried out in three altitudes I: 2 750 m, II: 2 930 and 3 250 m a.s.l. Calculated indexes were: species richness (S), Shannon’s diversity index (H’), Pielou’s evenness index (J’) and Simpson dominance (<IMG SRC="/img/revistas/rbt/v56n2/signo3.jpg" WIDTH=25 HEIGHT=14>). An ANOVA of two way test was used to evaluate the effect of altitude and sampling date on the total density of the springtails. The total number of species was 24 (altitude I=17, altitude II=14, altitude III=13). The greatest density was at altitude III and the highest species richness at altitude I. Americabrya arida and Willowsia mexicana were dominant. There is a positive significant effect of altitude on their density. The highest Sörensen similarity between communities was 59 % ( altitudes II and III). Rev. Biol. Trop. 56 (2): 739-748. Epub 2008 June 30.