RESUMO
The succession of carrion fauna and the decomposition stages were studied in summer for two years in open pastures of the Department of Paysandú, Uruguay (32°21'5â³S; 58°3'37â³). Each year, three pig carcasses (Sus scrofa) were placed in wire mesh cages, 100 m apart from each other. Each carcass was surrounded by pitfall traps, and a modified Malaise trap was placed above. Daily samplings were carried out to collect the insects present in the carcasses and the traps, and body and environmental temperatures were measured. The composition of carrion entomofauna and the decomposition patterns were markedly similar in both sampling years. The decomposition process was rapid, that is, the time to reach the remains stage was 7 days in all treatments, both years. The mosaic nature of decomposition was observed. Both Chrysomya albiceps (Wiedemann) and Cochliomyia macellaria (Fabricius) behaved as primary invaders of the carcasses, although the former species and its larvae were dominant. The first adult blow flies emerged after 6 days. The remains stage was characterized mainly by both adults and larvae of Dermestes maculatus. This preliminary study represents the first contribution to the knowledge of cadaveric succession in Uruguay. Its seasonal replication supports the succession pattern obtained.
Assuntos
Besouros/fisiologia , Dípteros/fisiologia , Comportamento Alimentar/fisiologia , Entomologia Forense , Mudanças Depois da Morte , Animais , Umidade , Larva/fisiologia , Suínos , Temperatura , UruguaiRESUMO
Experiments were conducted to study the life cycle of Dermestes maculatus and to establish the total developmental time and the developmental time of immature stages, in relation with six different temperatures. We also analyzed the variations in size, morphology, and other indicators of temporal variation during life cycle of D. maculatus, in relation with temperature. One hundred larvae were selected per experiment, reared individually. The remaining larvae were reared to evaluate and establish temporal variations among the instars (length, cephalic width, and dry weight). In all trials, survivorship was greater than 50% and seven larval instars were found. Data of the average developmental time of immature stages and of the total cycle, at different temperatures, are provided. This is of relevance when estimating particularly, a minimum PMI. No relation between morphometric parameters and temperature was found, suggesting that other random factors may have been involved. Thus, this indicates that the method of isomegalen diagrams could not be used for calculating PMI.
Assuntos
Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Temperatura , Animais , Entomologia , Ciências Forenses , LaboratóriosRESUMO
The aim of this work was to study taphonomic marks that cadaveric coleopteran can produce under controlled conditions. To evaluate this, pig trotters were initially exposed to adults of Dermestes maculatus De Geer at 21 ± 5°C and a 12:12-h day/night cycle. Observations were made and photographs taken every 4-5 days for 9 months. When feeding and reproducing, D. maculatus produced, in both adult and larvae stages, different types of marks such as holes, striations, scratches, and pits in several kinds of tissue such as integumental, connective, and muscular, in both their fresh and dried stages. Bite marks were also evident. The results in this study provide not only taphonomic but also biological and forensic information. This is the first time that this kind of experiment has been performed.