The biodiversity inventory is an urgent task for insect conservation. Particularly, the urban green spaces (non-built-up areas) within urban environments are a fundamental element to the maintenance and restoration of biodiversity. We describe the diversity of saprophagous Calyptratae in three urban green spaces: a private garden, an urban park, and a natural reserve in Buenos Aires City, Argentina, and we compare the presence of native and cosmopolitan species. A total of 14,688 specimens were collected, representing 62 species. The flies were captured by netting them on attractive baits, rotten viscerae of chicken and dog faeces. The three most abundant species, Cochliomyia macellaria, Tricharaea (Sarcophagula) occidua, and Chrysomya albiceps, represent 81.70 % of the total sample. Native species represented a 67.24 % of the total sample and presented an increase in terms of richness in larger and less modified spaces. Cosmopolitan species treated as "global homogenizers" were identified.

El inventario de la biodiversidad es una tarea urgente para la conservación de los insectos. En particular, los espacios verdes urbanos (áreas sin edificaciones) dentro de entornos urbanos son un elemento fundamental para el mantenimiento y restauración de la biodiversidad. Se describe la biodiversidad de los Calyptratae saprófagos en tres espacios verdes urbanos: un jardín privado, un parque urbano, y una reserva natural en la Ciudad de Buenos Aires, Argentina, y se compara la presencia de especies cosmopolitas y nativas. Un total de 14.688 especímenes fueron colectados, representando 62 especies. Las moscas fueron capturadas con red de mano sobres cebos de atracción, vísceras de pollo en descomposición y heces caninas. Las tres especies más abundantes, Cochliomyia macellaria, Tricharaea (Sarcophagula) occidua, y Chrysomya albiceps, representan el 81,70 % de la muestra total. Las especies nativas representan 62,24 % de la muestra total y muestran un incremento en términos de riqueza en espacios más grandes y menos modificados. Se identificaron las especies cosmopolitas tratadas con "homogenizadores globales".

The false stable fly, Muscina stabulans (Fallén), was surveyed along an urban-rural gradient at Almirante Brown, Buenos Aires province, Argentina. Samples were taken at monthly intervals from May 2005 to April 2007. Hourly captures of adult flies (10:00 am - 04:00 pm) were taken at each sampling date with a hand net. The baits used were 250 g of rotten cow liver and 250 g of fresh dog faeces exposed in shaded and sunny areas. The entire sample accumulated 358 specimens. The number of specimens captured during the second year was higher than in the fi rst year. Muscina stabulans was more abundant at urban-suburban sites. Females showed significant preferences for cow liver. We caught more specimens in shaded areas. The hourly activity increased toward the afternoon at the three sites. The present work was the first ecological study related to a muscid species in Argentina.

We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond, Costanera Sur Reserve, Buenos Aires, Argentina. The usage of different floating plants by immature instars and their overwintering was analized. The percentage of usage of the available floating macrophytes (Pistia, Limnobium, and Salvinia) by the larvae and pupae was studied. Also, we defined positivity (P+) as the percentage of plants with immature instars for each plant genus on a monthly basis. Ma. immature instars were captured throughout the year and Pistia was the resource most commonly exploited by the mosquitoes. The percentage of fourth-instar larvae and pupae on Pistia roots with respect to total immature instars captured was assessed on a monthly and seasonal basis. The proportion of fourth-instar larvae and pupae from both species of Mansonia on water lettuce roots, showed significant differences between months and seasons. Our results suggest that the populations of Ma. indubitans and Ma. titillans in Macáes Pond, survive during winter mainly as fourth-instar larvae.