Improving geographic distribution data for a putatively extinct species, a test case with a disappeared fly.

Global biodiversity loss by anthropogenic impacts is an under-recognized form of global environmental change. Global defaunation is still poorly documented in the case of insects, showing a significant decrease in populations and diversity. The blowfly Neta chilensis (Walker 1837) is poorly known and presumed to be confined to southern-South America, with an unclear distributional pattern. It was last collected in 1984. We aimed, through Ecological Niche Models, to identify regions highly suitable for N. chilensis; to test the suitability of regions with doubtful records; to understand the impact that climatic change and human activities have had; and to identify regions with high chances to find it. We compiled 130 presence records from Argentina and Chile and 117 localities where it was sought but not found between 1987 and 2018. Results indicate that suitable conditions are restricted to southern and central Chile and to southwestern Argentina, that doubtful records are predicted in unsuitable areas, that N. chilensis occupies a narrow niche and that its decline is not mainly caused by climate changes but more probably to habitat loss and to the biological invasion. We identified two regions where the chances of finding the species are higher in the case that it is not extinct already.

Effect of Vegetation Types on Sarcophagidae (Diptera) in Ciervo de los Pantanos National Park, a Natural Remnant in a Highly Endangered Landscape.

Species diversity can be affected by the structure of vegetation, which may vary in height, density, and distribution of trees, shrubs, and other plant types, configuring different types of habitats. In this study, we evaluated the diversity of sarcosaprophagous Sarcophagidae communities inhabiting the remnant representative habitats protected in Ciervo de los Pantanos National Park: grasslands, forests, and wetlands. We hypothesized that the abundance and diversity of flesh flies would be higher in the grasslands and wetlands than in the forest patches. Samplings were carried out in each habitat type using baited traps during the four seasons in 2015, 2016, and 2019. We collected 585 sarcophagid flies of 17 species. Fifteen species were recorded in grasslands, twelve in the wetlands, and seven in the forests, Tricharaea (Sarcophagula) occidua (Fabricius) (Diptera: Sarcophagidae) being the most abundant (58.3% of the total sample). As expected, the highest abundance was recorded in grasslands whereas the lowest was found in forests. In addition, flesh fly abundance was affected by season. Sarcophagid assemblages differed between habitats and the overall dissimilarity was mainly explained by nestedness. This study provides important information about sarcosaprophagous sarcophagid flies in a little-studied protected natural area in Argentina, which is fundamental for their conservation and useful in forensic investigations.

Diversity and seasonal dynamics of an assemblage of sarcophagid Diptera in a gradient of urbanization.

Sarcophagid species inhabiting different locations in a rural-urban gradient were surveyed in the east central Argentine district of the Almirante Brown, Buenos Aires province. The main objectives of this research were to identify the most prevalent sarcophagid species and to describe community richness and diversity according to the degree of urbanization and the environmental variables measured in three locations within a rural-urban gradient sampled during two years from May 2005 to April 2007. Spatial and seasonal variations were the main factors involved in structuring the sarcophagid communities. Diversity was lower in urbanized areas than in rural ones. Bait and microhabitat preferences (sunny or shady places) and seasonal fluctuations were described for 17 sarcophagid species.

The population ecology of Muscina stabulans (Fallén) (Diptera: Muscidae), along an urban-rural gradient of Buenos Aires, Argentina.

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.

The population ecology of Muscina stabulans (Fallén) (Diptera: Muscidae), along an Urban-Rural Gradient of Buenos Aires, Argentina

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.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, 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 analyzed. 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.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, 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.