0.05). It has been demonstrated that most of the species found in native vegetation occur also in the eucalypt plantations, although these ones present a drastic diminution of the species density, suggesting that the ant regional richness do not depend on the complexity of the habitat, because the cerrado ant fauna is well conserved in the eucalypt plantations, contradicting most of the literature on this subject.]]>

Bioindicadores ambientais: insetos como um instrumento desta avaliaçãoAtividades agrícolas, florestais e do setor imobiliário vêm, ao longo do tempo, modificando ambientes ecologicamente estruturados. As consequências são drásticas e, por isso, faz-se necessária a busca por ferramentas e instrumentos para diagnosticar e monitorar a diversidade biológica desses locais. Os insetos têm-se destacado como potenciais organismos bioindicadores e isso se deve ao fato de apresentarem grande capacidade perceptiva, no que se refere a alterações do meio ambiente, principalmente por seu apurado sistema sensorial, que lhes permite qualificar condições ambientais em determinadas situações e, ainda, quantificar danos causados ao meio. Um dos problemas que podem ser associados a este setor é a falta de padronização e definição de protocolos de coleta e avaliação da biodiversidade, para que esses resultados possam ser analisados e extrapolados para diferentes ambientes antropizados. Neste trabalho, é contextualizada a importância da entomofauna como bioindicadora, em ecossistemas. Palavras-chave:Biodiversidade, bioindicadores, impacto ambiental, insetos.

ABSTRACT. SPECIES RICHNESS OF SOlL ANT FAUNA lN AN EUCALYPT PLANTATION ANO A SECONO GROWTH FOREST. This investigation was conducted to compare the soil ant fauna of an eucalypt plantation to that of a second growth forest; both areas located in the Zona da Mata of Minas Gerais, Brazil. Tuna lish, honey and cracker baits were used to collect ants along a transect and pitfall traps wcre distributed in central 900 m 2 of each site. A total of 64 species belongi ng to 26 genera were collected in the 12 weekly samples; 54 species were captured in the torest and 45 in the Eucalyplus grandis plantation. A total of eight species presented frequencies above 10% in at least one area. Species richness was higher in the second growth fores!. Additional studies should be considered for further generalizations ofthe results. KEY WORDS. Brazilian atlantic forest, eucalypt, second growth forest, soil ant fauna

Leaf‐cutting ants are highly polyphagous insects, but some plants escape their attack due to the presence of secondary metabolites that are toxic to the ant–fungus symbiosis. Previous studies have demonstrated that the terpenoid β‐eudesmol extracted from Eucalyptus species (Myrtaceae) is responsible for the deleterious behavior in colonies of leaf‐cutting ant species. The objective of this study was to evaluate the effect of β‐eudesmol on workers of the leaf‐cutting ant Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae). This chemical caused behavioral modification in the colonies, leading to mutilation and death of workers. It is suggested that β‐eudesmol interferes with colony nestmate recognition. As a consequence, colony cohesion may be disrupted by β‐eudesmol what could be used as an additional control tactic against this important pest ant.

Impact of Formicid Granulated Baits on Non-Target Ants in Eucalyptus Plantations According to Two Forms of Application ABSTRACT-The effect of localized and systematic use of granulated bait for cutting ant control was assessed on a community of non-target ants in eucalyptus in the municipality of Bom Despacho, Minas Gerais State, Brazil. The ants were collected in Winkler traps on three occasions: eight days before bait distribution, eight and sixty days after distribution by removing the mirmecofauna from 50 1-m 2 samples of litter. A total of 102 species was collected belonging to six sub-families. The seven most frequent ant species were analyzed in more detail to assess more precisely the consequences of insecticide treatments. The study showed that systematic control caused negative and more prolonged impact on the ant community than localized control.