Seasonality of insect succession and pig carcass decomposition in a natural forest area in southeastern Brazil

In this study, successional patterns, relative abundance of larvae and adul ts of sarcosaprophagous insects, carcass decay, diversity and seasonality o f species, and their potential as forensic indicators were studied. Four ex periments were carried out in each season in a natural area of southeastern Brazil. Two pigs (Sus scrofa L.) were used in each experiment and were exp osed to sunlight and shade, respectively. The Calliphoridae outnumbered the Sarcophagidae in specimens collected and reared from the carcasses. More i nsects were collected from carcasses exposed to the sun, while a larger num ber of specimens were reared from those in the shade. Temperature and rainf all influenced the stages of carcass decay and insect activity and abundanc e. Chrysomya albiceps was the most abundant species in all four experiments . The carcasses were used as a protein source and substratum for ovipositio n. The dark putrefaction and fermentation stages yielded more flies than th e other stages. These results show that flies are important in carcass deca y and are, therefore, also of forensic importance. Seven species can be con sidered valuable forensic indicators in Southeastern Brazil. However, only three species were useful as forensic indicators in wooded areas: P. interm utans, H. segmentaria, and H. semidiaphana.