How CSIs Use the Field of Forensic Entomology
Have you ever wondered why Grissom remained so obsessed by insects? In many episodes, he picks through a body, holds up a tiny insect captured with his tweezers and breaks someone’s alibi by refuting the timeline. Does it really work that way? The answer is “kind of.”
Grissom uses a field called forensic entomology to break alibis and establish realistic timelines, especially time of death. In forensic entomology, the scientist uses the insects and arthropods inhabiting a decomposing body as a means of determining the Post Mortem Interval (PMI), what a victim consumed before dying and of refuting abuse by a human.
Types of Forensic Entomology
In science, these three areas of entomology are called medicolegal, urban and stored product pests. Medicolegal entomology studies the necrophagous or carrion insects feeding on and found on or in human remains. Urban entomology studies insects feeding on the dead and living. Scientists study skin markings and compare them to the bites of insects. Some insect bites can get mistaken for physical abuse by another human being. Stored product pests entomology studies the insects found in food and liquids typically involving cases of food contamination.
Speed of Bug Development
The medicolegal applications get used the most often. The investigators study the development of the insects on a decomposing body. Adult insects circle a body until they decide on a suitable area to lay eggs. The egg grows into the larval or maggot stage in which it does most of the eating. Next it grows into pupa stage, then adult. Each of these stages of development require a specific time period to reach. This helps date activity occurring to the body although weather conditions can influence this.
If you visit the CSI exhibit, one of many Las Vegas attractions for kids that teaches while you play, you can come enjoy a hand-on edutainment experience and learn more about forensic entomology.