A study of forensically important Necrophgous Diptera in Kuwait.

Abstract

Medico-legal entomology is the use of insects in legal matters. Knowledge of the distribution, biology, ecology and behavior of insects found at a crime scene can provide information on when, where and how the crime was committed. Although
insects are known to have been used in the detection of crimes for a long time, there has been no great increase in the popularity of the subject until the last 30 years.
Forensic entomology is recognized in many countries as an important tool in legal investigations. Unfortunately, it has not received much attention in some parts of the world such as Kuwait and other Arab countries where the value of insect as indicators in criminal investigations has not been fully realised.
For forensic entomology to be effective in legal investigations, knowledge of local insect assemblages and their population dynamics is essential. This study was conducted to gather database information on necrophagous flies and their
succession on carrion using rabbits as experimental models. It allowed quantitative and qualitative comparisons to be made in four habitats (desert, urban, agriculture and coastal). In addition, the insects sampled from the carcasses were compared with those collected from human corpses as part of recent investigations in Kuwait.
Eleven families of necrophagous flies were collected at four habitats; the most important families to breed on carrions were Calliphoridae such as Calliphora vicina Robineau-Desvoidy 1830, Chrysomya albiceps (Wiedemann 1819), Chrysomya megacephala (Fabricius 1794) and Lucilia sericata (Meigen 1826), and Sarcophagidae such as Parasarcophaga ruficornis (Fabricius 1794), Sarcophaga Africa (Wiedemann), Wohlfahrtia nuba (Wiedemann 1830) and unidentified
Sarcophaga sp. which can used as forensic indicators to estimate the PMI. The most important species in respect to abundance and frequency were Chrysomya albiceps
and P. ruficornis.
There was a significant diversity of fly species between different habitats. Four stages of decomposition were observed (fresh, bloated, decay, and dry). The decomposition of carcasses in urban habitats was faster than that of other habitats. There was an interaction between decomposition of carcasses and colonization by insects and correlation between the stage of decay and the succession of insect families and
species arriving at a carcass. The decomposition was slower when the arrival of the insects was delayed. The abundance and diversity of flies increased with the onset of bloated and dry stages.
Of the 13 human case studies, 10 were male and 3 females; their ages ranged from few days (newborn) to 53 years. They were of different nationalities. The cause of death was either homicide, suicide, drug abuse, toxicity or abortion. The
necrophagous fly composition and their succession patterns obtained from real forensic cases showed a number of basic similarities to those observed on rabbit carcasses as experimental animals. The involvement of the study in legal
investigations helped determine the manner and cause of death in two cases and estimate the PMI in one case. Although this study was conducted in one season and for a short period, it adds to the known species richness in Kuwait as it recorded
several species of flies for the first time in Kuwait. The results provide additional information to forensic entomologists by having identified species that are associated with carrion in this region of the world. The study made the officials and the criminal investigation team aware of and familiar with forensic entomology, a step which may initiate future studies and interest in the application of insect evidence in legal
investigations.