Thiago Izzo

Catasetum brasilandense, a new species from the Brazilian state Mato Grosso is described. This species was found in a difficult access area with rugged topography, in the municipality of Nova Brasilandia, in the vicinity of the Rio das Mortes. It is closely related to Catasetum gladiatorium, differing mainly by the labellum structure. Résumé Une nouvelle espèce de Catasetum, Catasetum brasilandense, est décrite. Originaire de l'état brésilien du Mato Grosso, cette espèce a été découverte dans une zone d'accès difficile, présentant une topographie accidentée, sur la commune de Nova Brasilandia, à proximité du Rio das Mortes. Elle est étroitement apparentée à Catasetum gladiatorium, s'en distinguant principalement par la structure du labelle.

Ants are ecologically dominant and have been used as valuable bio-indicators of environmental change or disturbance being used in monitoring inventories. However, the majority of inventories have concentrated on ground-dwelling ant fauna disregarding arboreal fauna. This paper aimed to list the ant species collected both on the ground and in the vegetation of the Parque Estadual do Cristalino, an important protected site in the center of the southern Amazon. Moreover, we compared the composition of the ground dwelling and vegetation foraging ants. Two hundred and three (203) species distributed among  23 genera and eight subfamilies were sampled, wherein 34 species had not yet been reported in the literature for Mato Grosso State. As  expected, the abundance and richness of ants was higher on the ground than in the understory. Also, the composition of the ant assemblages was different between these habitats (with only 20% occurring in both) indicating that complementary methods which include arboreal and terrestrial ants are indicated for efficient inventory. This study provides an inventory of the arboreal and ground ant fauna contributing to the knowledge and conservation of Amazonian ant fauna.

Nous avons étudié la composition de la faune des Scarabaeinae coprophages d’îles
fluviales sur la rivière Juruena, en Amazonie brésilienne méridionale, d’un point de vue d’une analyse taxinomique. Nnous
avons effectué des prélèvements sur sept îles et deux localités témoins situées sur les berges continentales du fleuves. Nous
avons récoltées 41 espèces. Toutes ces espèces sont largement distribués dans la forêt amazonienne. Neuf d’entre elles n’ont
été rencontrées que sur les îles, 24 ne l’ont été que sur le continent et seulement huit sont communes aux deux entités. La
faune des Scarabaeinae coprophages insulaires est composée principalement d’éléments de forêt várzea ou de lisière, sans
représentant du genre Eurysternus, et d’éléments de forêt primaire amazonienne. Ces résultats suggèrent que trois
paramètres modèlent la composition de la faune des bousiers en milieu insulaire fluvial: inondations et perturbations
associées, compétition pour les ressources (liée à la présence de primates) et potentiel de dispersion des différentes espèces.
En fonction du contexte et de l’âge de la formation des îles, ces trois paramètres revêtent une importance relative différente
selon les espèces. L’analyse plus en profondeur de ces paramètres nécessite la description précise de la communauté étudiée
d’un point de vue taxinomique.

We evaluated the taxonomic composition of Scarabaeinae dung beetles inhabiting fluvial islands in Juruena River,
southern Brazilian Amazon.We sampled seven islands and two localities on each side of the mainland.We collected 41 species,
all of which are widely distributed in the Amazon rainforest. Nine of these were exclusive to the islands, 24 were exclusively
found on the mainland while eight species were found in both the islands and the mainland. The insular dung beetle fauna is
mainly composed of typical species of várzea forest or edge forest/gap with the absence of Eurysternus and elements of primary
forest in the Amazon. This result suggests that three main processes are shaping these communities: flooding and associated
disturbance events, resource competition (presence of primates) and differential dispersal power among species. Depending on
the context and age of island formation all these processes could have different levels of importance. Specific questions regarding
these processes requires a previous knowledge of the taxonomic composition of these communities.

The conflict caused by large carnivore attacks on livestock constitutes a major threat to the conservation of carnivore species worldwide. The objective of this study was to determine what factors influence jaguar Panthera onca and puma Puma concolor attacks on cattle at a ranch in the Brazilian Pantanal. Cattle herds were monitored for 57 months, and data were collected for each recorded mortality event. The economic impact of predation was calculated. We parameterize a generalized linear model with negative binomial error distribution to model the influence of water levels of the Paraguay River, size of cattle herd and the age structure of the herd on the monthly number of cattle killed by big cats. Over half of all recorded herd mortality events were caused by large cat predation, resulting in a maximum 2.83% of the average annual herd size and representing an annual financial loss of US$22 400.00. A positive relationship was found between the frequency of monthly attacks and the water level of the Paraguay River, whereas a negative relationship was found between monthly attacks and proportion of adult cattle in the herd. Juveniles were taken more frequently than adults. Increased water levels caused the herd to concentrate on higher ground usually near forested areas, suggesting an increase in cattle vulnerability to predation. A greater proportion of adults in the herd may also increase the possibility for defensive behavior, likely resulting in greater protection of younger cattle. Understanding the factors that predispose cattle to predation by big cats contributes to the establishment of management strategies that may reduce losses and, ultimately, conflict.

ABSTRACT The benefits obtained by an organism when involved in a mutualistic interaction vary depending on environmental factors, as well as among the identity of the involved species. In this study, we showed that four ant species, Crematogaster brasiliensis, Allomerus octoarticulatus, and two unidentified Azteca species can be found associated to the myrmecophite Cordia nodosa in riparian forests in the South of Amazonia. This composition of ant-associated species is more similar in forests of Andean Amazon than in Central Amazonia. The colonization of an ant colony on C. nodosa seems to be vital in order to decrease herbivory, as increased the probability of a plant sets fruits. Moreover, even though we did not find significant differences in herbivory among plants colonized by different ant species, the probability of a plant produces fruits is much lower when it is colonized by Allomerus ants. Overall, this study shows that C. nodosa depends on ants to reproduce. However, based on other empirical studies across the Amazon, our results also suggest that Allomerus ants can act as flower castrator, acting as a parasite over its geographic range.

The benefits obtained by an organism when involved in a mutualistic interaction vary depending on environmental factors,
as well as among the identity of the involved species. In this study, we showed that four ant species, Crematogaster brasiliensis,
Allomerus octoarticulatus, and two unidentified Azteca species can be found associated to the myrmecophite Cordia nodosa
in riparian forests in the South of Amazonia. This composition of ant-associated species is more similar in forests of Andean
Amazon than in Central Amazonia. The colonization of an ant colony on C. nodosa seems to be vital in order to decrease
herbivory, as increased the probability of a plant sets fruits. Moreover, even though we did not find significant differences in
herbivory among plants colonized by different ant species, the probability of a plant produces fruits is much lower when it
is colonized by Allomerus ants. Overall, this study shows that C. nodosa depends on ants to reproduce. However, based on
other empirical studies across the Amazon, our results also suggest that Allomerus ants can act as flower castrator, acting as a parasite over its geographic range.

Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants' composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this "night-turnover" suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences.

We evaluated the reciprocal effects between foragers of the ants Camponotus crassus and of the stingless bees Trigona hyalinata on aggregations of the honeydew-producing treehopper Aetalion reticulatum. The interactions were observed in Bauhinia variegata ( ...

... padrões co-evolutivos envolvendo formigas e plantas. AGRAdeCIMentos Agradecemos à Fazenda São nicolau/onF-Brasil/Pegeout, por ceder as condições logísticas que tornaram possível a realização desse trabalho. Agradecimentos ao Prof. Dr. Rafael Arruda pelo apoio ...

Este guia não busca trazer uma revisão profunda sobre a biologia, ecologia e evolução das formigas. Na realidade, apresentamos de forma condensada informações básicas sobre esses temas que a maioria dos mirmecólogos (as pessoas que estudam formigas) devem conhecer. Muita informação importante ficou de fora, mas esse viés foi proposital. Foi a única forma que encontramos para enfatizar as chaves de identificação e os gêneros de formigas da forma que merecem, mantendo o guia em um tamanho razoável. Discutir em profundidade a biologia, ecologia e evolução das formigas que ocorrem no Brasil, fatalmente terminaria em um livro com mais de 2.000 páginas, e a mesma informação está disponível em outros livros especializados. Porém, mesmo com o viés dado, esperamos que o guia seja útil também para graduandos, pós graduandos e mesmo pesquisadores da área.

Although several studies have shown that ants can recognize chemical cues from their host plants in ant-plant systems, it is poorly demonstrated in ant gardens (AGs). In this interaction, ant species constantly interact with various epiphyte species. Therefore, it is possible to expect a convergence of chemical signals released by plants that could be acting to ensure that ants are able to recognize and defend epiphyte species frequently associated with AGs. In this study, it was hypothesized that ants recognize and differentiate among chemical stimuli released by AG epiphytes and non-AG epiphytes. We experimentally simulated leaf herbivore damage on three epiphyte species restricted to AGs and a locally abundant understory herb, Piper hispidum, in order to quantify the number of recruited Camponotus femoratus (Fabricius) defenders.

Page 1. Journal of Tropical Ecology (2004) 20:675–682. Copyright © 2004 Cambridge University Press DOI: 10.1017/S0266467404001749 Printed in the United Kingdom Leaf damage induces ant recruitment in the Amazonian ant-plant Hirtella myrmecophila ...

Modeling clays have been used in several ecological experiments and have proved to be an important tool to variables control. The objective of our study was to determine if fruit color in isolated and grouped displays influences the fruit selection by birds in the field using artificial fruits. Data were collected in six plots distributed homogeneously in 3 km long trails with a minimum distance of 0.5 km. We used a paired experimental design to establish our experiments, so that all treatments were available to the local bird community in each plot. Overall, red was more pecked than brown and white. Isolated red and brown displays were significantly more pecked than others display. Even though our study was conducted in small spatial scales, artificial fruits appeared to be efficient in register fruit consumption attempts by bird. Although inconclusive about selective forces that sharp the dynamics of fruit color polymorphisms and choice by frugivorous birds, our findings corroborate recent studies wherein birds showed preferences by high- over low-contrast fruit signals.

Modeling clays have been used in several ecological experiments and have proved to be an important tool to variables control. The objective of our study was to determine if fruit color in isolated and grouped displays influences the fruit selection by birds in the field using artificial fruits. Data were collected in six plots distributed homogeneously in 3 km long trails with a minimum distance of 0.5 km. We used a paired experimental design to establish our experiments, so that all treatments were available to the local bird community in each plot. Overall, red was more pecked than brown and white. Isolated red and brown displays were significantly more pecked than others display. Even though our study was conducted in small spatial scales, artificial fruits appeared to be efficient in register fruit consumption attempts by bird. Although inconclusive about selective forces that sharp the dynamics of fruit color polymorphisms and choice by frugivorous birds, our findings corroborate recent studies wherein birds showed preferences by high- over low-contrast fruit signals.

Este trabalho lista os gêneros de formigas coletados tanto no solo quanto na vegetação do Parque Estadual Cristalino, MT, Brasil. Também traz o número de morfoespécies para cada um dos gêneros identificados, o local de ocorrência e informações complementares quanto à distribuição e biologia.
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This work lists the genera of ants collected both on the ground and in the vegetation of Parque Estadual Cristalino, MT, Brazil. Also, we provided information on the number of species by genus, occurence and information about the distribution and biology.

Adarilda Petini-Benelli is currently developing her PhD research project "Phylogeny of Catasetum and gender monograph for Mato Grosso" under the guidance of Thiago J. Izzo (Mato Grosso Federal University - UFMT) and Eric C. Smidt (Paraná Federal University - UFPR). While she is not done with her research, Petini-Benelli - in collaboration with other authors - is presenting the preliminary results through the publication of field guide #767 Orchidaceae, genus Catasetum - Mato Grosso, BRASIL (http://fieldguides.fieldmuseum.org/guides/guide/767).
This 5-page field guide is the first one published on our web page presenting native species of Mato Grosso State with photos showing sexual dimorphism which is a major feature of the genre and photos of 40 species that are part of the Endangered IUCN status red list (look for the orange circle under the photo number)