Ecologia de comunidades de insetos associados à decomposição de Sus scrofa (Linnaeus) (Suidae) expostos em um igarapé de terra firme na Reserva Florestal Ducke, Manaus, Amazonas, Brasil

Abstract

In order to determine the pigs decompositors insects in fresh water environment, there were conducted four experiments, two in each season of the year (rainy season and less rainy season) for a period of two years (2008 and 2009), at the Reserva Florestal Ducke, Manaus, pects related to succession, richness, relative abundance and different stages of the pigs decomposition. In each experiment there were used three domestic pigs, Sus scrofa L. (Suidae), weighting approximately 43 kg each, and taken alive until the collection place to be killed by a gun shot in the frontal region of its head, and placed in three metallic jails, that were partially submerged in three different areas along the Barro Branco stream, keeping approximately 90m distance from eacho ther area. The collected taxons were 35.655 belonging to five orders, 20 families, 40 morphotypes and 56 species. Among the blowflies, Chrysomya albiceps (Wiedeman, 1830) was the most abundant species with 10,880 individuals, while the specie Peckia (Pantonella) smarti (Lopes, 1941) belonging to Sarcophagidae family presented 679 specimens. Six stages were completed during the decomposition of the carcass: the first stage was the SF (submerged fresh), adapted to PSF (partially submerged fresh), having the average decomposition cycle as of 19.5 days in the Less Rainy period of 2008 and 2009 and 24.5 days in the Rainy season of 2008 and 2009. The early floating, floating decay and bloated deterioration stages, presented more Diptera abundance. The rearing of eggs and larvae yielded the following species: Chrysomya albiceps (Wiedemann, 1830), Hemilucilia segmentaria (Fabricius, 1805), H. semidiaphana (Rondani, 1850), Chrysomya putoria (Wiedemann, 1830), Lucilia eximia (Wiedemann, 1819), Paralucilia paraensis (Mello, 1969), Paralucilia fulvinota (Bigot, 1877), Paralucilia pseudolyrcea (Mello, 1969) (Calliphoridae); Peckia (Pattonella) smarti (Lopes, 1941), Peckia (Pattonella) pallidipilosa (Curran & Walley, 1934), Peckia (Pattonella) intermutans (Walker, 1861) and Peckia (Peckia) chrysostoma (Wiedemann, 1830) (Sarcophagidae). Larvae Calliphoridae and Sarcophagidae were the major consumers of pig, some adults which the biology were studied in the region, shown favorable to be used as forensic indicator. In fourteen species of adult Calliphoridae only 9 (64%) were collected in the immature form, and in fifteen of Sarcophagidae, only 4 (26%), demonstrating the importance of studying the biology of the larvae of these species. Among the aquatic immature, only chironomids were collected and raised to adulthood and found feeding on the soft parts of the pig body tissue using the bones as shelter. According to the results obtained from immature created, it is possible to estimate the overflow time of a corpse involving river systems. These results may indicate that in both periods (less and rainy and seasons) differed only in relation to precipitation, possibly due to the regularity of high temperature and relative humidity, characteristic in the Amazon region. The climatic periods have not come to negatively influence the composition and abundance of species. Likewise, there was no influence of temperature and pH of the water on the decomposition of body partially submerged in the different periods studied.