Synthesiomyia nudiseta (van der Wulp, 1883) is a synanthropic muscid found in tropical and subtropical zones around the world. The larvae of this species are a secondary agent of myiasis with necrophagous habits and play an important role in forensic entomology, as they are used as an indicator of post-mortem interval. Adults can be considered vectors of etiological agents such as Escherichia coli and Shigella dysenteriae. Due to its ability to adapt to different environmental conditions, its high dispersal capacity (shown by its introduction to Europe), its predatory habits in the last larval stage and the difficulty of identifying it, a very important goal is to update our knowledge about this species. Therefore, the main objective of this paper is to review the identification, geographical distribution and biology of this species in order to provide better support to investigations involving this fly.
The larval development of Chrysomya albiceps and Lucilia sericata is a well-known and valuable tool for estimating the postmortem interval (PMI). The third instar larvae of Ch. albiceps are facultative predators of the larvae of other necrophagous dipterans, and this behaviour is undoubtedly an important factor to consider. Both species are found together during human autopsies in Spain and other parts of Europe, where they cohabit, so a precise knowledge of their larval coexistence data is essential. The aim of this study is to investigate their coexistence and the intraguild predation of Ch. albiceps on L. sericata under experimental conditions and in real case reports. To analyse intra- and interspecific competition, four densities were used under controlled abiotic conditions [25ºC, 60-70% RH and 12:12 (D:N)]. The experimental data were compared with data corresponding to their coexistence in natural conditions, so annual activity and forensic case reports for both species were studied. The results indicate that the mortality of immature specimens in both species, the preimaginal developmental time, and adult size were affected by competition. In natural conditions, adult coexistence during the spring-summer period was confirmed. The simultaneity of the two species colonising human corpses is frequent in the studied area, with Ch. albiceps being the dominant species, and L. sericata the relevant species for estimating the minimum postmortem interval.