1. What bugs can tell us about the dead…….
Forensic Entomology
What bugs can tell us about the dead…….

2. What the insects can tell us….
Flies and beetles follow a life cycle that allow scientists to estimate how long a body has been dead
Post Mortem Interval (PMI) is the time that has elapsed since the person died and can be estimated by observing the insect evidence on the body.

3. Fly Life Cycle

4. PMI is established by ….. Observing what life cycle stages are present
Larva passes through 3 stages called instars which are identified and used to determine the PMI
Need to know some larva anatomy to be able to identify the correct instar

5. Fly Larva Anatomy
The anterior end of the larva contains mouth hooks which are used to tear at the flesh of the

6. Fly Larva Anatomy
On the posterior end is the structure that the larva breathes through called spiracles

7. Spiracles
The number of slits in the spiracles helps to identify the age of the larva
The shape of the spiracles will differ for various species

8. Fly Life Cycle Information
life-cycle-of-a-blowfly/
Stage
Approximate Size
Color
1st appears
Duration
Characteristics

9. Factors that affect Insect Development
Temperature
Moisture
Wind
Time of day
Season
Exposure to elements
Variations among individual insects
Use of insects to predict time of death is only an estimate!
All environmental variations must be recorded at time of collection!!!!!

10. What about in the ocean under water?
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