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Forensic Entomology

Masters degree in Psychology, Minor in forensics, dedicated to making the mental health stigma dissipate as quickly as possible.

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Forensic Entomology: The study of crime bugs

Forensic Entomology is one of the most interesting branches of the investigative forensic discipline. Entomology is defined as the study of insects and forensics is defined as scientific tests and techniques used in the detection of crime (Merriam-Webster 2021). When combining these two schools of science you get a Forensic Entomologist. These professionals study the death and decay that bugs have on once living tissue over time. Using these techniques they cannot only tell how long a body has been decomposing but also if the body was killed in a region.

There are three different areas of Forensic Entomology; medicolegal, urban, and stored product pests. Medicolegal is known as the criminal component as it deals with bugs that feed or reproduce in human remains and are known as necrophagous (Forensic 2021). Using perfected techniques, the forensic entomologist observes, records, and collects samples of the insects from the body. By analyzing the development stages of the larvae and adults, they can determine the time a body has been deceased. Depending on the situation, there have been cases where insects from another region have been found on a body which led them back to the place where the murder was commited. While this is the most important area when it comes to criminal forensics, there are many other factors that affect the results. Weather is the number one affector of accuracy when it comes to determining death. This is because hot scorching conditions or wet soggy conditions can change the amount of insects present and the state of development. A body that is left in the hot sun will draw more insects than one that is in a frozen climate (Joseph 2011). It can also be difficult if the body is wrapped in something, burned beforehand, or buried. A body laying in the exposed air would be prone to more insect activity than one buried in the dirt, however, there would be more worm activity in the body underground. All of these factors must be considered when establishing a time of death. There are five stages of development (Joseph 2011):

  1. Fresh Stage (1-2 days) - cellular breakdown occurs attracting insects
  2. Bloated Stage (2-7days) - Putrefaction begins and gases are produced causing the corpse to inflate and the temperature to rise. Odor becomes apparent.
  3. Decay Stage (5-13days) - the abdominal wall is penetrated resulting at the end of the bloated stage. The smell is horrid and detectable from a distance. Internal temperature rises 14 degrees above ambient.
  4. Post Decay (10-23days) - most tissue has been consumed. Very little hair, cartilage, and tissue remain. Bone is exposed and adult insects begin to leave the corpse.
  5. Remains (18-90+days) - when only nearly bone remains and the remaining tissue is dried. Insect adults are no longer present and the larvae population dwindles.

The urban component focuses on insects that feed on the living and dead paying particular attention to the markings the insect makes in the skin. This area of forensics has components of both civil and legal crimes and is commonly used to dispute apartment infestations by determining where the infestation occurred (Forensics 2021).

The Stored Pest component focuses on insects that are found in food. These are the cases you hear about in the news when insects are found in food supplies served to the general public. While there are legal limits to how many insects are permitted in a batch of product, when a story hits the news, a whole team of forensic entomologists investigates how the bugs got in, where they nested, how to prevent future occurrences, etc (Forensics 2021).

There are multiple challenges when it comes to upholding the law in terms of evidence. Firstly, as mentioned previously the weather holds a great deal of influence over the reproduction and development of insects. They also have issues with retaining original samples. Since insect lives are relatively short and court cases take a notoriously long time, there are chances that the original insects from the case are no longer able to be tested from the degradation of their corpses. While documentation can solve most of these problems there are rare occasions where testing needs to be redone and the sample is too degraded to work with (Joseph 2011). This affects the 6th amendment rights of the defendant who has a right to a speedy trial, but we all have experienced the system not being so speedy.

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This discipline is able to be called as an expert witness on almost all things dealing with insects. However, cases have gone against the entomologist if he wasn’t able to act professionally. This could be restating sentences without further depth, failure to submit all documentation, being too candid, etc (Hall 2010). With a discipline as gruesome as insects consuming human flesh, I am not sure how one could be candid.

Forensic Entomology. (n.d.). Crime Museum. Retrieved April 9, 2021, from

Hall, R. D. (2010). The Forensic Entomologist as an Expert Witness [PDF].

Joseph, I., Mathew, D. G., Sathyan, P., & Vargheese, G. (2011). The use of Insects in Forensic
Investigations: An Overview on the Scope of Forensic Entomology. Journal of Forensic
Dental Sciences, 3(2), 89–91.

Merriam-Webster. (n.d.). Entomology. In dictionary. Retrieved April 08,
2021, from

Merriam-Webster. (n.d.). Forensic. In dictionary. Retrieved April 08,
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