O objetivo desse trabalho foi estudar estágios de vida de Chrysomya megacephala em uma arena circular permitindo a dispersão larval pós-alimentar combinada a partir do centro das larvas de C. megacephala e C. albiceps. Para determinar a localização de cada pupa a distância a partir do centro, a profundidade e o peso foram coletados. Do total de larvas soltas as fêmeas de C. albiceps se enterraram mais profundamente que os machos, alcançando uma profundidade de 10,74 cm. Apesar dessa diferença, as larvas de C. megacephala apresentaram resultado em média maiores para todas a variáveis, particularmente a distância, a qual foi 16,02 cm para essa espécie e 12,30 para C. albiceps. Além disso, as larvas de C. albiceps predaram 30 larvas de C. megacphala durante esse processo em ambos os experimentos. Esses estudos podem ser utilizados em Entomologia forense porque a estimativa do Intervalo Pós Morte (IPM) é um dos aspectos mais importantes em medicina legal e a não consideração das larvas que dispersam mais longe ou se enterram mais podem levar a uma subestimativa do IPM.

The aims of this work was to study the life stages of Chrysomya megacephala in a circular arena allowing the combined radial post-feeding dispersal from the center of the arena of C. albiceps and C. megacephala larvae. To determine the location of each pupa, the distance from the center, the depth and weight of each pupa formed were analyzed. For the larvae of C. albiceps, females released buried deeper than males, reaching an average depth of 10.74 cm and C. megacephala larvae presented greater average results than C. albiceps for all variables, particularly distance, which was 16.02 cm for this species and 12.30 cm for C. albiceps. C. albiceps larvae preyed on 30 C. megacephala larvae in both experiments. These results could be used in forensic entomology because the evaluation of Post Mortem Interval (PMI) was one of the most important aspects of legal medicine, and it could be underestimated if the older dispersing larvae or those that dispersed longer and faster or deeper, were not taken into account.

Moscas-varejeiras usam substratos discretos e efêmeros para nutrição larval. Após a exaustão do suprimento de comida, as larvas dispersam na procura por locais para pupação na outros recursos de alimento em um processo conhecido como dispersão larval pós- alimentar. Nesse estudo, alguns dos aspectos mais importantes desse processo foram investigados em larvas de moscas-varejeiras Chrysomya megacephala expostas a uma variação de ciclos luz: escuro (LD) (0:24h, 12:12h e 24:0h) e incubadas em tubos cobertos com vermiculita. Para cada pupa, o peso corpóreo e a profundidade de enterramento foram determinados. Testes estatísticos foram usados para examinar a relação entre profundidade de enterramento e o peso corpóreo e o fotoperíodo a que esse enterramento ocorreu. O estudo do comportamento de enterramento na dispersão larval pós-alimentar pode ser útil para estimar o intervalo pós-morte (IPM) em cadáveres humanos em medicina forense.

Blowflies use discrete, ephemeral breeding sites for larval nutrition. After exhaustion of the food supply, the larvae disperse in search of sites to pupate or to seek other sources of food in a process known as post-feeding larval dispersal. In this study, some of the most important aspects of this process were investigated in larvae of the blowflies Chrysomya megacephala exposed to a variety of light: dark (LD) cycles (0:0 h, 12:12 h and 24:0 h) and incubated in tubes covered with vermiculite. For each pupa, the body weight and depth of burrowing were determined. Statistical tests were used to examine the relationship of depth of burrowing and body weight to photoperiod at which burrowing occurred. The study of burial behavior in post-feeding larval dispersing can be useful for estimating the postmortem interval (PMI) of human corpses in forensic medicine.

Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or to additional food source, process referred as postfeeding larval dispersal. Some of the most important aspects of this process were investigated in Chrysomya megacephala, utilizing a circular arena to permit the radial dispersion of larvae from the center. To determinate the localization of each pupa, the arena was split in 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farther are those with higher weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI) for human corpses in medico-criminal investigations.