Page 8 - Natures Witness Entomology

Pre-Lab

Solutions

Background Procedure

1. What is the role of a forensic entomologist in 6. What should you record on your Species
a homicide investigation? Separation sheet?
The forensic entomologist can determine the Characters that are between two flies of
time of death if the bodies have already cooled different species but the same life stage.
to the ambient temperature.

7. How many individuals from the sample
2. Why are insects important when determining collected from the decedent will you identify?
post mortem interval (PMI)? Ten
If the body is exposed, the predictable
growth rates of many insects can be used to
determine the post mortem interval. 8. How will you determine the species and life
stage of these individuals?
3. What is an instar? You will use the characters identified and
An instar is a larval growth stage characterized written on the Species Separation sheet, as
by the larvae shedding a smaller cuticle and well as those on the Fly Life stage chart.
forming a larger one.

4. What are some factors that may delay fly
oviposition?
If the decedent is located in an enclosed area
inaccessible to flies, or if the decedent died
during night-time or during a cold period, flies
will not lay eggs immediately.

5. Flies develop at predictable rates. What
measure is used to make this prediction?
Degree-hours, degree-days, or another
measure of temperature-time.

8 THE MYSTERY OF LYLE AND LOUISE