Houseflies speaking for the conservation of natural areas: a broad sampling of Muscidae (Diptera) on coastal plains of the Pampa biome, Southern Brazil

ABSTRACT The Brazilian Coastal Plain of the Pampa Biome (CPPB), has suffered fragmentation caused by resource extraction and cattle raising. In turn, conservation proposals are needed to prevent the anthropisation of Pampa natural areas. The first step towards conservation proposals by using insects is fauna inventories, providing data support for legislators. Thus, we undertook a regional and broad-scale sampling survey to investigate the diversity of Muscidae flies in protected and non-protected areas of CPPB. In addition, we carried out an ecological guild diversity analysis as a metric approach of bioindication. The Muscidae sampling resulted in 6314 specimens, 98 species taxa in 31 genera. Based on diversity estimators, our sampling represents 70-86% of all muscids of CPPB. The highest diversity occurs in Pelotas streams (non-protected) and Taim Ecological Station (a huge protected area). Despite the fact these areas are more diversified and present more predatory muscid species than others, invasive species associated with livestock were observed at a higher level, providing evidence of the impact of livestock proximity to protected areas. Based on biological characters of Muscidae species and ecological guild analysis, we were able to identify: (i) high diversity of carnivorous species associated with forested and more preserved areas and (ii) a high level of a few saprophagous species as indicator of anthropisation process. In general, our results represent a significant step towards understanding Muscidae in Southern Brazil, and we demonstrate how the population ecology of muscid flies supports data to conservation proposals.

Insects of forensic importance from Rio Grande do Sul state in southern Brazil / Insetos de importância forense do Rio Grande do Sul, sul do Brasil

The experiment was conducted throughout the year 2005, at the Universidade Federal de Pelotas campus. The objectives of the study were to analyze the decomposition of rabbit (Oryctolagus cunniculus L.) with mean weight 2.67 Kg carcass and describe the interaction of insects acting on it, as well as the insect's potential use in legal medicine. We collected 5.239 insect specimens; 1.827 of them were obtained from larvae collected from carcasses and reared. The specimens were identified and 20 species were of forensic importance. The species Lucilia eximia (Wiedemann, 1819) and Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae) were better indicators of post-mortem interval (PMI) because they occurred in all seasons and were the first to reach the carcass. Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805) (Diptera, Calliphoridae), Muscina stabulans (Fallén, 1817) and Synthesiomyia nudiseta (Wulp, 1883) (Diptera, Muscidae) can disclose death time because they occur only in certain months of the year. Oxyletrum discicolle (Brullé, 1840) (Coleoptera, Silphidae) and Dermestes maculates De Geer, 1774 (Coleoptera, Desmestidae) were found in advanced stages of decomposition.

Durante todas as estações do ano de 2005 foi conduzido um experimento em uma área do campus da Universidade Federal de Pelotas. O objetivo do estudo foi analisar a decomposição de carcaças de coelho (Oryctolagus cunniculus L.) pesando 2,67 Kg em média e descrever como os insetos atuam na decomposição e seu possível uso na medicina-legal. Foram coletados 5.239 espécimes; 1.827 foram obtidos a partir da criação de imaturos coletados na carcaça. Foram identificadas 20 espécies com importância forense. As espécies mais propícias para serem usadas com indicadoras de intervalo post-mortem (IPM) são Lucilia eximia (Wiedemann, 1819) e Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae) por terem sido encontradas em todas as estações de coleta e por serem uma das primeiras espécies a chegar à carcaça. Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805) (Diptera, Calliphoridae), Muscina stabulans (Fallén, 1817) e Synthesiomyia nudiseta (Wulp, 1883) (Diptera, Muscidae) são espécies que podem indicar época da morte, pois ocorrem em meses específicos do ano. Oxyletrum discicolle (Brullé, 1840) (Coleoptera, Silphidae) e Dermestes maculatus De Geer, 1774 (Coleoptera, Desmestidae) são encontrados em estágios avançados de decomposição.