Trophic Guild Structure of a Canopy Ants Community in a Mexican Tropical Deciduous Forest

Ants constitute a very important element in the canopies of tropical forest. The species richness, composition and diversity of ant canopy community in a tropical deciduous forest in the Pacific Cost of Mexico was studied. The sampling was performed by fogging method in a watershed of the Chamela Biological Station, Jalisco State, Mexico. Ants represented 0.5% of all invertebrates in the tree canopy of Chamela, and a total of 46 ant morphospecies from 17 genera were collected. Camponotus and Cephalotes contributed with 13 and 6 species respectively, and the most abundant ants were species of Crematogaster, Tapinoma, Cephalotes and Camponotus. Ant composition was broadly similar at the two sites, and on different canopy species, although significant differences in abundance were apparent for some individual ant species. The dominant guild in the canopy was the omnivourous in all study, but differences in guild trophic composition were recorded in each fogging. The ant community in the canopy of Chamela has shown low spatial variation, but the composition of ant species and trophic guilds have important seasonal variations, demonstrated variations in the exploitation of resources along the year, and vertical migrations of ant species from soil and shrub layer to canopy in the tropical deciduous forest

COMPARISON OF THE WORLDWIDE CAVE COLLEMBOLA AT THE GENERIC LEVEL 1

ABSTRACT: We present a comparison at the generic level of the cave Collembola fauna recorded around the world. Using the biogeographical provinces proposed by KEY WORDS: Diversity, cave, distribution, springtails, troglobites Caves represent a very peculiar environment, drawing the attention of many different kinds of research, including archaeology, biology, hydrology, geology and ethnology, and cultural aspects including legends and myths (Barr an

First Mexican species of the genus Cosberella (Collembola, Hypogastruridae)

A new species of Cosberella is described and illustrated from a temperate forest of Citlaltépetl formation, Veracruz State. It is characterized by the following combination of characters: Th I with 2 + 2 dorsal setae; 2 + 2 axial setae on Th II–III; two capitate tenent hairs on each leg; unguiculus half the length of unguis; unguis with tooth; six dental setae and Abd VI without anal spines. A key for the species of the genus is included

Composição e grupos funcionais de formigas epiedáficas (Hymenoptera: Formicidae) em agroecossistema irrigado e em áreas não agrícolas

The objective of this work was to evaluate the species composition and functional groups of ants in nonagricultural (NA) and in irrigated areas (S, seasonal irrigation; P, irrigation with well water; W, irrigation with wastewater) in an arid agricultural region in central Mexico, throughout 2005 and 2006. A total of 52,358 ants belonging to 6 subfamilies, 21 genera and 39 species was collected using pitfall traps. The species best represented in all plots were: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum and Dorymyrmex spp. NA plots recorded the highest density of ants. The highest values for diversity (H') and equitativity (J') were recorded in NA and P plots, while the lowest were recorded in W plots. Cluster analysis showed two different groups regarding species composition: NA-S and W-P. Functional groups recorded were: dominant Dolichoderinae, three species; subordinate Camponotini, five species; hot climate specialists, three species; tropical climate specialists, seven species; cold climate specialists, five species; cryptic species, one species; opportunists, six species; generalized Myrmicinae, nine species. Agricultural activity affects the structure of the ant community with epiedaphic forage, and the constant use of irrigation wastewater in conjunction with intense agricultural practices has negative effect upon species richness of epiedaphic ants.La composición y grupos funcionales de hormgias fueron determinados en zonas no agrícolas (NA) y en agroecosistemas con diferentes calidad de agua de irrigación (temporal =T; irrigado con agua de pozo = P; irrigado con agua residual=W), en una zona agrícila árida del centro de México, de 2005 a 2006. Un total de 52,228 hormigas pertenecientes a seis subfamilias, 22 géneros y 34 especies fueron colectadas. Los géneros mejor representados en todas las parcelas fueron Dorymyrmex, Forelius, Monomorium y Pheidole. Las parcelas NA registraron la mayor densidad de hormigas. Los valores más altos de diversidad y equitatividad se eocnetraron en las parcelas P, mientras que los valeoes más bajos estueiorn en las parcelas NA. Un análisis de cluster mostró que las parcelas NA plots son diferentes en composición de las parcelas agrícolas. Los grupos funcionales registrados fueron: Dolichoderinae Dominantes: 3 especies; Camponotini Subordinadas: 2 especies; Especialistas de Climas Cálidos: 3 especies; Especialistas de Clima Tropical: 8 especies; Especialistas de Clima Frío: 3 especies; Especies Crípticas: 1 especie; Oportunistas: 6 especies; Myrmicinae Generalizadas: 8 especies. La actividad agrícola afecta la estructura de la comunidad de hormgias con forrago edáfico y el uso constante de agua de irrigación tiene un efecto negativo sobre la riqueza de especies de las hormigas edáficas.O objetivo deste trabalho foi avaliar a composição de espécies e os grupos funcionais de formigas em áreas não agrícolas (NA) e em áreas irrigadas (S, irrigação sazonal; P, irrigação com águas de poço; W, irrigação com água residuária) em uma região agrícola de clima árido da região Central do México durante 2005 e 2006. Um total de 52.358 formigas pertencentes a 6 subfamílias, 21 gêneros e 39 espécies foi coletado por meio de armadilhas Pitfall. As espécies mais bem representadas em todas as parcelas foram: Forelius pruinosus, Pheidole obtusospinosa, Monomorium minimum e Dorymyrmex spp. As parcelas NA registraram a maior densidade de formigas. Os maiores valores de diversidade e equitatividade foram observados nas parcelas NA e P, e os menores, nas parcelas W. A análise de cluster mostrou Sgrupos funcionais registrados foram: Dolichoderinae dominantes, três espécies; Camponotini subordinadas, cinco espécies; especialistas de clima quente, três espécies; especialistas de clima tropical, sete espécies; especialistas de clima frio, cinco espécies; espécies crípticas, uma espécie; oportunistas, seis espécies; Myrmicinae generalizados, nove espécies. A a utilização água residuária, ena riqueza de espécies de formigas epiedáficas

Foraging Activity and Trophic Spectrum of Red Ant Pogonomyrmex barbatus

Foraging strategies can be influenced by many factors such as abundance, availability, and toxicity of the resources. In arid zones, the distribution and productivity of plants also act as additional factors that affect foraging strategies. Twenty colonies of Pogonomyrmex barbatus ants were studied in an arid zone of central Mexico to evaluate the trophic niche breadth in two sites with contrasting productivities in terms of their diversity and amount of resources during two seasons. The results suggest that when the resources are abundant as in the rainy season, the trophic niche breadth is reduced in sites with high productivity and, in the same sites, the trophic niche breadth increases when the resources are limited as in the dry season. In contrast, the trophic niche breadth is similar in both conditions of resource availability (i.e., rainy and dry seasons) at sites with low productivity. During the dry season, populations of P. barbatus showed a similar foraging behavior in sites with high and low productivity. Thus, the particular characteristics of a site can significantly affect the foraging strategies of the ants in those environments

Diversity and dynamics of microarthropods from different biotopes of Las Sardinas cave (Mexico)

aBstract an ecological study of the microarthropod communities from las sardinas cave was undertaken. Four different biotopes were studied over the course of a year: bat guano, litter, soil under the chemoautotrophic bacteria colonies and as a control, plain soil without litter or guano. a total of 27,913 specimens of a total of 169 species were collected. analysis of Variance (anoVa) showed that there is a significant effect of biotope on the recorded density, and the post hoc Tukey's test showed that guano is the most different biotope with the highest value of density recorded. The interaction between season and biotope variables was not significant. In the most extreme case, 99 percent of the microarthropods in soil under chemoautotrophic bacteria were mites, mainly in the family Histiostomidae

Diversidade de colêmbolos (Hexapoda) de acordo com o gradiente de altitude

The objective of this work was to elevate gradient effect on diversity of Collembola, in a temperate forest on the northeast slope of Iztaccíhuatl Volcano, Mexico. Four expeditions were organized from November 2003 to August 2004, at four altitudes (2,753, 3,015, 3,250 and 3,687 m a.s.l.). In each site, air temperature, CO2 concentration, humidity, and terrain inclination were measured. The influence of abiotic factors on faunal composition was evaluated, at the four collecting sites, with canonical correspondence analyses (CCA). A total of 24,028 specimens were obtained, representing 12 families, 44 genera and 76 species. Mesaphorura phlorae, Proisotoma ca. tenella and Parisotoma ca. notabilis were the most abundant species. The highest diversity and evenness were recorded at 3,250 m (H' = 2.85; J' = 0.73). Canonical analyses axes 1 and 2 of the CCA explained 67.4% of the variance in species composition, with CO2 and altitude best explaining axis 1, while slope and humidity were better correlated to axis 2. The results showed that CO2 is an important factor to explain Collembola species assemblage, together with slope and humidity.O objetivo deste trabalho foi avaliar o efeito do gradiente de elevação na diversidade de Collembola, em uma floresta temperada no Vulcão Iztaccíhuatl, México. Quatro expedições foram organizadas de novembro 2003 a agosto 2004, em quatro altitudes (2.753, 3.015, 3.250 e 3.687 m). Em cada local foram medidas a temperatura, a concentração de CO2 e a umidade do ar, além da inclinação do terreno. A influência de fatores abióticos na composição da fauna foi avaliada nos quatro locais de coleta, por meio da análise de correspondência canônica. Coletaram-se 24.028 espécimes, distribuídos em 12 famílias, 44 gêneros e 76 espécies. Mesaphorura phlorae, Proisotoma ca. tenella e Parisotoma ca. notabilis foram as espécies mais abundantes. A diversidade e a equitabilidade mais elevadas foram registradas a 3.250 m (H' = 2.85; J' = 0.73). A análise canônica mostrou que os eixos de correspondências 1 e 2, juntos, explicam 67.4% da variação na composição específica, em que o CO2 e a altitude explicam melhor o eixo 1, ao passo que a inclinação e a umidade estão mais bem relacionadas ao eixo 2. Os resultados mostraram que o CO2 é um fator importante para explicar o agrupamento das espécies de Collembola, juntamente com a inclinação e a umidade

Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning