Determinants of ant species spatial distribution in habitats from central Argentina

A great challenge in ecology is to link patterns in nature with the factors that determine species coexistence and community structure. In general, these patterns have been associated with different environmental conditions and species traits. The coexistence of ant species could be affected by the availability of food and nesting resources, which depend on vegetation diversity and structural complexity. In this study, we attempt to reproduce, through null models, the properties of ant community structure in areas with different physiognomy of vegetation associated to different wildfire regimes. The null model construction considered ant traits such as occurrence frequency, body size, and nest type; and site characteristics such as vegetation height and extra-floral nectar availability, and their combinations. The null models were compared to observed species segregation and nestedness patterns. Ant species were more aggregated in space than expected by chance. Vegetation height and extra-floral nectar availability were included in the most successful models in predicting ant segregation and aggregation pattern. Furthermore, ants’ body size was enough to reproduce the nestedness of species distribution in sites. Our results suggest that under post-fire conditions, habitat complexity, resource availability and species traits such as body size may be the determinants of ant community structure

The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and hostuse efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure

Species-Area Relationships Are Controlled by Species Traits

The species-area relationship (SAR) is one of the most thoroughly investigated empirical relationships in ecology. Two theories have been proposed to explain SARs: classical island biogeography theory and niche theory. Classical island biogeography theory considers the processes of persistence, extinction, and colonization, whereas niche theory focuses on species requirements, such as habitat and resource use. Recent studies have called for the unification of these two theories to better explain the underlying mechanisms that generates SARs. In this context, species traits that can be related to each theory seem promising. Here we analyzed the SARs of butterfly and moth assemblages on islands differing in size and isolation. We tested whether species traits modify the SAR and the response to isolation. In addition to the expected overall effects on the area, traits related to each of the two theories increased the model fit, from 69% up to 90%. Steeper slopes have been shown to have a particularly higher sensitivity to area, which was indicated by species with restricted range (slope  = 0.82), narrow dietary niche (slope  = 0.59), low abundance (slope  = 0.52), and low reproductive potential (slope  = 0.51). We concluded that considering species traits by analyzing SARs yields considerable potential for unifying island biogeography theory and niche theory, and that the systematic and predictable effects observed when considering traits can help to guide conservation and management actions

Anuran stomach contents from six localities of Colombian dry forest

The Dataset contains species names, localities, individual's size and their stomach contents of anuran species inhabiting six localities of Colombian dry forest

Keystones In A Tangled Bank

Ecological network studies highlight the importance of individual species to community conservation.335607514491451Watts, D.J., Strogatz, S.H., (1998) Nature, 393, p. 440Buchanan, M., (2002) Nexus: Small Worlds and the Groundbreaking Science of Networks, , Norton, New YorkPascual, M., Dunne, J.A., (2006) Ecological Networks: Linking Structure to Dynamics in Food Webs, , Oxford Univ. Press, New YorkWaser, N.M., Ollerton, J., (2006) Plant-Pollinator Interactions: From Specialization to Generalization, , Univ. of Chicago Press, ChicagoStouffer, D.B., Sales-Pardo, M., Sirer, M.I., Bascompte, J., (2012) Science, 335, p. 1489Aizen, M.A., Sabatino, M., Tylianakis, J.M., (2012) Science, 335, p. 1486Pocock, M.J.O., Evans, D.M., Memmott, J., (2012) Science, 335, p. 973Milo, R., (2002) Science, 298, p. 824Stouffer, D.B., Bascompte, J., (2010) Ecol. Lett., 13, p. 154Sabatino, M., Maceira, N., Aizen, M.A., (2010) Ecol. Appl., 20, p. 1491Paine, R.T., (1969) Am. Nat., 103, p. 91Kaartinen, R., Roslin, T., (2011) J. Anim. Ecol., 80, p. 622Novotny, V., (2010) J. Anim. Ecol., 79, p. 1193Lewinsohn, T.M., Prado, P.I., Jordano, P., Bascompte, J., Olesen, J.M., (2006) Oikos, 113, p. 17

Susceptibility of larvae of Aedes aegypti (Linnaeus) (Diptera: Culicidae) to entomopathogenic nematode Heterorhabditis bacteriophora (Poinar) (Rhabditida: Heterorhabditidae)

Aedes aegypti (Linnaeus) (Diptera: Culicidae) es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) en larvas de A. aegypti se registró por primera vez bajo condiciones de laborato - rio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1). Los juveniles infectivos (JIs) utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae). La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito . Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti , se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida

Uniting pattern and process in plant-animal mutualistic networks: a review

BACKGROUND: Ecologists and evolutionary biologists are becoming increasingly interested in networks as a framework to study plant–animal mutualisms within their ecological context. Although such focus on networks has brought about important insights into the structure of these interactions, relatively little is still known about the mechanisms behind these patterns. SCOPE: The aim in this paper is to offer an overview of the mechanisms influencing the structure of plant–animal mutualistic networks. A brief summary is presented of the salient network patterns, the potential mechanisms are discussed and the studies that have evaluated them are reviewed. This review shows that researchers of plant–animal mutualisms have made substantial progress in the understanding of the processes behind the patterns observed in mutualistic networks. At the same time, we are still far from a thorough, integrative mechanistic understanding. We close with specific suggestions for directions of future research, which include developing methods to evaluate the relative importance of mechanisms influencing network patterns and focusing research efforts on selected representative study systems throughout the world

Susceptibilidad de larvas de Aedes aegypti (Linnaeus) (Diptera: Culicidae) al nematodo entomopat\uf3geno Heterorhabditis bacteriophora (Poinar) (Rhabditida: Heterorhabditidae)

Aedes aegypti (Linnaeus) (Diptera: Culicidae) is a vector of etiological agents of yellow fever and dengue. An alternative to chemical control of this vector is the use of biological agents. Entomopathogenic nematodes are effective in pest control. The infectivity and life cycle of an Argentinean isolate of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) on Aedes aegypti larvae is registered for the first time under laboratory conditions. For each experimental unit, 30 second-instar larvae were exposed to 8 nematode doses (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1). The infective juveniles (IJs) used were multiplied on Galleria mellonella (Lepidoptera: Pyralidae). The infective continuity of IJs obtained from A. aegypti was tested applying the nematodes in a 100:1 dose on mosquito larvae. Larval mortality rates ranged from 0% to 84%. The larval mortality, the number of nematodes developed inside mosquito larvae and the number of new IJs increased with the increase of the nematodes dose. The results indicated that H. bacteriophora is able to infect A. aegypti larvae, and these nematodes can develop and produce new IJs, allowing the continuity of its life cycle.Aedes aegypti (Linnaeus) (Diptera: Culicidae) es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) en larvas de A. aegypti se registró por primera vez bajo condiciones de laboratorio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1). Los juveniles infectivos (JIs) utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae). La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito. Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti, se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida.Fil: Peschiutta, María Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Universidad Nacional de la Patagonia Austral; ArgentinaFil: Cagnolo, Susana Raquel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Almirón, Walter R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; Argentin