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Insect Larvae May Help Detectives Track Down The Perpetrators Of Sex-Related Murders

Insect Larvae May Help Detectives Track Down The Perpetrators Of Sex-Related Murders

Most of us know that forensic scientists use certain insects that are present at a murder scene to gather evidence, and to determine when a murder occurred. This type of investigation is known as forensic entomology. The job of a forensic entomologist is very unpleasant, but also very important to solving a murder case. Recently Murdoch University forensic researchers have discovered a new method of identifying perpetrators of sexually motivated murders. Normally, after a person is found murdered, their bodies are examined and all fluids present on the victim’s body are gathered on a cotton swab before being placed into a plastic bag as evidence. These cotton swabs can often reveal the DNA in semen. Once the DNA is gathered, determining who commited the sexually motivated murder is easy. However, collecting bodily fluids, such as semen, on cotton swabs is not perfect, as the semen normally degrades after three days. Once the semen sample has degraded, the DNA contained within the sample is gone, and the sample becomes worthless. Luckily, the forensic researchers from Murdoch University have found a more ideal alternative to cotton swabs, and it happens to be the larvae from carrion flies of all things.

A small-scale study has demonstrated that human DNA can be preserved for up to twelve days after carrion larvae begin to feed on biological substances. Retrieving high quality DNA samples that are in good condition is necessary for creating a proper profile. Gathering genetic information from biological fluids that are left behind at a crime scene is often difficult, and this is especially true for semen, as it degrades rapidly. When graduate student, Laura Nutton, compared the quality of DNA from semen collected on a cotton swab with the DNA from semen contained within larvae, she found that the larvae kept the DNA in semen in tact for the longest period of time. This was only a small-scale study, so further studies will have to be conducted in order to gain a better understanding of the preservative potential of the carrion larvae. However, this method of DNA sampling seems promising.

Do you think that other types of larvae can be harvested in order to preserve certain biological fluids?