Forensic Entomology

By: Melonye McCree

What is Forensic Entomology?

Forensic Entomology is the use of insects, and their arthropod relatives that inhabit decomposing remains to aid legal investigations.

What types of insects are found?

Flies are found and have great powers of dispersal and they rapidly discover bodies. Blow flies are the most common insects associated with the dead body. Beetles in both their immature and adult form can also be found on dead bodies, these usually occur at later stages of decomposition.

Estimating Time Since Death (PMI)

There are two methods to estimate death: 1) using successional waves of insects and 2) maggot age development.

Insect succession is used if the individual has been dead for a month or longer.

Information from the site

1) The vegetation (trees, grass, bush, and shrubs), 2) the soil type (rocky, sandy, and muddy), 3) the weather at the time of collection (sunny, cloudy)

Information Needed from the Body

1) If the body was covered or buried (and with what), 2) If there is an obvious cause of death, 3) If there are wounds on the body or body fluids (blood etc) at the scene

Limitations of Forensic Entomology

1. Time of death estimates depend on accurate temperature information, but local weather patterns can be variable and data may come from stations quite distant from the crime scene.

2. Forensic entomology relies on insect abundance. In winter, there are fewer insects and entomology's use is limited.

3. Since it takes time to rear insects, forensic entomology cannot produce immediate results.

4. Treatments (like freezing, burial or wrapping) that exclude insects can affect estimates.

5. Since chemicals can slow or accelerate growth, insect evidence may be affected by the presence of drugs in a corpse's system.