Abstract The order Coleoptera is considered second highest in forensic importance in criminal cases involving violent death, because members of this order increase in richness and abundance as the decomposition process progresses. We present here the first Forensic Entomology (FE) case in Brazil where the carrion beetle, Oxelytrum discicolle (Coleoptera: Silphidae), was used to estimate the minimum post-mortem interval (m-PMI) in a forensic case. A female corpse, at an advanced stage of decomposition, was found on a deserted highway near Brasília/Brazil. The corpse was removed from the site, and insect samples were collected on and inside the corpse at the Forensic Medicine Institute of the Federal Police, following the specific FE protocols. The m-PMI was estimated considering two techniques, the pre-appearance interval (PAI) and the accumulated degree-days (ADD). The development stage of the larvae of O. discicolle allowed investigators to propose that this species was part of an earlier colonization, soon after death, with total length and prothorax width compatible with third instar larvae. Adult females of O. discicolle oviposited on the corpse at least 20 days before it was removed from the site where it was found, thus characterizing the m-PMI. This is the first case in which information on the development of the O. discicolle was used in a criminal investigation in Brazil.

ABSTRACT The intra-puparial development of the blowflies Cochliomyia macellaria (n = 310) and Lucilia cuprina (n = 470), was studied under controlled conditions in laboratory. The 3rd instar larvae were reared until they stopped feeding, and the pre-pupae were separated according to the size in larval length and degree of pigmentation and of the cuticle. We observe a set of five continuous events or phases: (1) pupariation, (2) larva-pupa apolysis, (3) cryptocephalic pupa, (4) phanerocephalic pupa and (5) pharate adult. The total time of the intra-puparial development, larva-pupa apolysis to pharate adult, lasted for 120 h (5 days) to C. macellaria and 210 h (8.75 days) to L. cuprina.

Desenvolvimento intra-pupal de fêmeas de Chrysomya albiceps (Wiedemann) (Diptera, Calliphoridae) A cronologia e as mudanças morfológicas que ocorrem durante o desenvolvimento intra-pupal de Chrysomya albiceps são descritos com base em 254 espécimes criados em laboratório. As larvas foram obtidas a partir os ovos postos por uma única fêmea. As pré-pupas foram separadas de acordo com a redução do comprimento larval, o grau de pigmentação e esclerotização da cutícula, depois da formação das pupas, 10 indivíduos foram fixados em solução de Carnoy e conservados em etanol 70%, e 10 indivíduos foram fixados a cada 3 horas, até completar as primeiras 24 horas (n = 80), os demais indivíduos foram fixados a cada seis horas até a hora 90 (n = 110), quando 54 fêmeas haviam emergido. As pupas foram imersas em de ácido fórmico a 5% por 48 horas e mantidos em etanol 70%, e então dissecados e analisados. C. albiceps mostrou quatro estágios intra-pupais, que foram descritos e comparados com aqueles descritos para Musca domestica, Calliphora erythrocephala, Sarcophaga bullata, Cuterebra tenebrosa, Oestrus ovis e Dermatobia hominis. Quatro estágios de desenvolvimento podem ser descritos: (1) apólise da larva-pupa, depois de três horas; (2) a pupa criptocefálica, depois de seis horas, (3) a pupa fanerocefálica, depois de nove horas, e a pupa farada após nove horas. O adulto farado está completamente formado após 81 horas.

Intra-puparial development of the females of Chrysomya albiceps (Wiedemann) (Diptera, Calliphoridae). The chronology and morphological changes that take place during intra-puparial development of Chrysomya albiceps is described based on 254 specimens reared in the laboratory. Larvae were obtained from the eggs laid by a single female. The pre-pupae were separated according to the reduction of larval length and the degree of pigmentation and sclerotization of the cuticle. After pupation, 10 individuals were fixed in Carnoy's solution and preserved in 70% ethanol, 10 individuals were fixed every 3 hours up to complete the first 24 hours (n = 80), the remaining individuals were fixed every six hours up to the 90th hour (n = 110) when 54 females emerged. The pupae were immersed in 5% formic acid for 48 hours and maintained in 70% ethanol, and then dissected and analyzed. C. albiceps shows four intra-puparial stages, each of which were described and compared with those described for Musca domestica, Calliphora erythrocephala, Sarcophaga bullata, Cuterebra tenebrosa, Oestrus ovis and Dermatobia hominis. Four developmental stages may be described: (1) the larva-pupa apolysis, after three hours; (2) the criptocephalic pupa, after six hours; (3) the phanerocephalic pupa, after nine hours; (4) the pharate pupa, after nine hours. The pharate adult is completely formed after 81 hours.

A morfologia e o tempo de desenvolvimento pós-embrionário de Chrysomya megacephala (Fabricius) criada em condições de laboratório e em dieta de carne bovina, foi descrita e comparada ao de outras espécies. Os parâmetros analisados foram à duração dos instares larvais e a morfologia. Para isso as larvas foram fixadas e preservadas em intervalos de tempo de 2 horas, desde a eclosão das larvas até a 50ª hora, a fim de se determinar o tempo de desenvolvimento de cada estágio. O tempo total de desenvolvimento larval para C. megacephala foi de 98 horas, com média de comprimento 15,51 mm. Essa espécie tem comportamento necrobiontófago e de importância sanitária e médico-legal, usada na estimativa do intervalo post-mortem em investigação criminal.

Morphology and duration of the post-embryonary development of Chrysomya megacephala (Diptera: Calliphoridae) in laboratory conditions. The morphology and developmental time of the post-embryonic stage of Chrysomya megacephala (Fabricius) reared in laboratory on a beef diet, is described and compared to those of other blow-flies species. The parameters analyzed were the duration of the larval stages and the morphology. Larvae were fixed and preserved at 2 hours intervals, from larval eclosion until the 50th hour of life, in order to determine the duration of each stage. The total period of larval development in C. megacephala was 98 hours and their mean length was 15.51 mm. This species presents a necrobiontophagous behavior and has sanitary and medico-legal importance, being used for estimating postmortem interval in criminal investigations.