This study aimed to evaluate the ant fauna in three different land-use systems: pasture, eucalyptus plantation and secondary forest, in southeastern Brazil. The ant fauna was collected with standardized pitfall traps. Forty-seven ant species were collected, belonging to 24 genera and six subfamilies. The total ant species richness was significantly higher in secondary forest (29 species) and eucalyptus plantation (25 species) when compared to the pasture (17 species), with no significant difference between the secondary forest and eucalyptus plantation. The species composition differed significantly between the three land-use systems. The frequency distributions of ant guilds in eucalyptus plantation and secondary forest differed significantly from the frequency in the pasture. The results demonstrated the importance of natural forests for the conservation of biological diversity of the Atlantic Forest, but they also indicated that eucalyptus plantations, with native understory plants, can harbor considerable ant diversity.

Este trabalho teve como objetivo avaliar a riqueza, a diversidade, a abundância e a composição da fauna de formigas em oito propriedades rurais com cultivo orgânico e oito com cultivo convencional, no município de Paraíba do Sul (RJ). Instalaramse em cada área cultivada 15 armadilhas tipo pitfall para a coleta das formigas. Amostraram-se 48 espécies de formigas no total, pertencentes a sete subfamílias e 23 gêneros. A riqueza nos cultivos convencionais foi de 29, e nos cultivos orgânicos, 38. Os valores médios de riqueza e diversidade de espécies e a abundância média foram maiores nas áreas com cultivo orgânico do que nos cultivos convencionais. O número de espécies cultivadas, a profundidade de cobertura vegetal morta e a temperatura estiveram entre as variáveis que mais afetaram a mirmecofauna. A composição de espécies de formigas variou significativamente entre áreas com cultivo convencional e orgânico (ANOSIM, R = 0,6099, p < 0,01). Os resultados corroboram a realidade de que a prática da agricultura orgânica constitui uma alternativa relevante aos cultivos convencionais, por promover a manutenção da biodiversidade local.

Urban Agriculture (UA) has emerged as an alternative capable of fostering sustainable relations among the economic, social and environmental spheres in cities. It consists of growing and processing traditionally rural food products in urban zones in consonance with the environmental considerations to promote sustainability. This study set out to analyze the interactions of agricultural activities and the urban ecosystem. A review of the literature and a case study of an Urban Agriculture program developed in the metropolitan area of the city of Rio de Janeiro showed that Urban Agriculture provides considerable ecosystem services, generates income, increases biodiversity conservation and fosters social inclusion, functioning as a mechanism for achieving equilibrium among the components of the urban ecosystem.

It is generally assumed that the choice of oviposition sites in arthropods is affected by the presence of food for the offspring on the one hand and by predation risk on the other hand. But where should females oviposit when the food itself poses a predation risk for their offspring? Here, we address this question by studying the oviposition behaviour of the predatory mite Amblyseius swirskii in reaction to the presence of its counterattacking prey, the western flower thrips Frankliniella occidentalis. We offered the mites a choice between two potential oviposition sites, one with and one without food. We used two types of food: thrips larvae, which are predators of eggs of predatory mite but are consumed by older predator stages, and pollen, a food source that poses no risk to the predators. With pollen as food, the predators preferred ovipositing on the site with food. This might facilitate the foraging for food by the immature offspring that will emerge from the eggs. With thrips as food, female predators preferred ovipositing on the site without thrips. Predators that oviposited more on the site with thrips larvae killed more thrips larvae than females that oviposited on the site without food, but this did not result in higher oviposition. This suggests that the females killed thrips to protect their offspring. Our results show that predators display complex anti-predator behaviour in response to the presence of counter-attacking prey.

The effects of pupal period and age on calling behavior of virgin females of Pseudaletia sequax were determined. Calling behavior of groups of females of similar age of pupation was observed every 10 min for six calling days. Females were considered calling when they assumed a characteristic position: wings and abdomen elevated, displaying the ovipositor and presumably releasing pheromone. Calling behavior was discontinuous. Females with a shorter pupal period took more time to start calling than females with a longer pupal period and called for a longer period. On the first day of calling, females took more time to initiate calling, on average during the seventh hour of the scotophase, whereas on the second day of calling, most females initiated calling during the fifth hour of the scotophase. On subsequent days of calling, the average time to initiate calling changed to the fourth hour of the scotophase. The mean time of calling per day decreased significantly with the number of days since first calling, and the mean number of calling bouts increased with days since first calling.