Introduction to Forensic Entomology
Entomology is a branch of science that studies insects (from the Latin words – entomonmeaninginsect and logosmeaningknowledge). The insect group has the largest number of species compared to other animals or plants. To date, there are around one million species of insects recorded. The actual number is not known as there are still many species yet to be recorded. The importance of entomology can be viewed in the role insects play either directly or indirectly in human lives.
Forensic entomology applies knowledge of insects to forensic work. It was applied for the first time in the 13th century and the science grew rapidly in the 19th century. Forensic entomology has contributed greatly in the estimate of the time since death and location of death in a decomposed body or one that is infested with insects.
The importance of Forensic Entomology
The science of forensic entomology can be used to estimate the time since death, to determine the locus of death, the cause of death and poisoning as a causative agent of death (analysis of larvae for poisons and DNA testing).
Insects that can be recovered from a corpse can be grouped into 4 types: Necrophages, Omnivores, Parasites and Predators, and Incidentals. The Necrophages are the first stage colonizers, the first species to breed on a corpse. This includes the blowfly and the beetle. During the Omnivores stage, the corpse will attract insect species like ants, wasps and other species of beetles.
The Parasites and Predators stage is the stage where the immature blowfly will be colonized by beetles, adult blowflies and hornets. In the last stage which is the Incidentals stage, insects such as centipedes and spiders will breed on a dead body as their natural habitat. For all these four stages, the time and location of death can be investigated by analysing the type of species that have bred on the dead body as well as their life cycle.
Of all the species that are attracted to a corpse, the most important insect is the blowfly. Its life cycle is as follows: egg ? larvae ? pupa ? adult blowfly. There are three stages of the larvae and each stage has a certain lifespan that can be used in analysing the time since death.
Forensic entomology in Malaysia
In Malaysia, the science of forensic entomology is growing rapidly through new analytical techniques and ongoing research. There are government agencies with laboratories that offer forensic entomology services such as the Institute for Medical Research (IMR) and Universiti Kebangsaan Malaysia. The types of insects that are found on a dead body will be collected and sent to these laboratories to be analysed as to the species and its life cycle. It is best to collect insects, larvae or eggs at the location where the dead body is found to obtain the best estimate of the time since death. However, weather conditions and the ambient temperature can affect the life cycle of an insect. The ambient temperature needs to be recorded at the location where the dead body is found. Humidity levels will also affect the type of insects colonizing a corpse.
|Last Reviewed||:||21 April 2014|
|Writer||:||Mohd Hilmi b. Saidin|
|Translator||:||Tengku Aisyah Yuhanis bt. Tengku Ngah|
|Accreditor||:||Dr. Mohamad Azaini b. Ibrahim|