Forensic entomology uses insects and other arthropods to help solve legal issues and criminal investigations. The presence, species, development stage, and lifecycle of insects on a corpse can help estimate time of death and postmortem interval. Key insects like flies, beetles, and skippers follow predictable patterns when colonizing a body over different decomposition stages. Forensic entomologists collect and analyze these insects and use temperature data to estimate postmortem interval and provide other evidence to help determine the circumstances of death.

1. Significance of Insects in Forensic
Entomology
Present By
Logeswaran V
2020505014
ENT 504 CLASSIFICATION OF INSECTS
(1+1)

4. • Forensic entomology is the application and
study of insects and other arthropods biology
to legal issues, especially in a court of law.
• These insect colonizers can be used to estimate
the time of death i.e., time interval between
death and corpse discovery, also called
Postmortem Index (PMI), movement of the
corpse, manner and cause of death and
association of suspects at the death scene.

5. • Sung Tz'u (1235 AD) – Chinese “death investigator” wrote
“The Washing Away of Wrongs”.
• First forensic entomology case recorded -
A murder by slashing occurred in a village, and the local
death investigator was ordered to solve the crime. The
investigator had all villagers bring their sickles to one spot
and lay them out before the crowd. Flies were attracted to one
of the sickles, probably because of invisible remnants of tissue
still remaining on it, and the owner subsequently broke down
and confessed to the crime.

6. Historical Landmarks in Forensic Entomology

7. Bernard Greenberg is regarded as the father
of modern Forensic Entomology.

8. What do Forensic Entomologists
Do?
• Forensic Entomologists apply their knowledge of
entomology to provide information for criminal
investigations.
• A forensic entomologist’s job may include:
– Identification of insects at various stages of
their life cycle, such as eggs, larva, and adults.
– Collection and preservation of insects as
evidence.
– Determining an estimate for the postmortem
interval or PMI using factors such as insect
evidence, weather conditions, location and
condition of the body, etc.
– Testifying in court to explain insect-related
evidence found at a crime scene.

9. • Flies and beetles follow a life cycle that allow
scientists to estimate how long a body has been
deceased.

10. Examples of Diptera (Flies)
Flesh Fly
(Sarcophagidae)
Striped thorax
Blow & Greenbottle Flies
(Calliphoridae)
Metallic thorax and abdomen
House Fly
(Muscidae)
Cheese Skipper
(Piophilidae)
Early Stage
Decomposition
Late Stage
Decomposition
Life Cycle of a
Calliphoridae Fly

11. Blue/Green bottle Flies
Blow flies
Family: Calliphoridae
•Blowflies often are an attractive blue-green, metallic
color, leading to the common English names, blue-bottles
and green- bottles.
•They can pick up faint traces of the odor of decay from
up to 20 km away and lay their eggs in a suitable corpse.
•Blow flies are one of the first insects to arrive at a
cadaver– they prefer fresh, moist flesh

12. Life cycle of Blow fly
It takes approximately 14-16 days from egg to adult depending on the temperatures
and humidity levels at the location of the body.

13. Flesh Flies
Family: Sarcophagidae
• Flesh flies arrive early at a crime scene and often
lay their eggs in open wounds on mammals.
Adults are most common at corpses in the early
stages of decomposition when the corpse is moist.
Common House Flies
Family name: Muscidae

14. Cheese Skipper
Family name: Piophilidae
• Cheese flies are attracted to the cheesy odor which
emanates from a corpse during the later stages of
decomposition ( 3 to 6 months after died), particularly
when the body is undergoing butyric fermentation.
• They are also common pests of cheeses.
Cheese Skippers have
been found in coffins
buried up to 3 m deep
and in corpses up to 10
years old.

15. Examples of Coleoptera (Beetles)
Carrion Beetles (Silphidae)
Adults & larvae feed on fly larvae
Early to Late Stage Decomposition
Late Stage Decomposition
Rove Beetles
(Staphylinidae)
Predator of fly eggs
Early Stage Decomposition
Hide Beetles
(Scarabidae)
Usually the last to arrive
Clown Beetles
(Histeridae)
Predator of fly eggs
Ham & Checkered Beetles
(Cleridae)
Predator of flies & beetles;
also feed on dead tissue Skin Beetles (Dermestidae)
Feed on dried skin & tissues

16. Carrion Beetles
Family name: Silphildae
• The first beetles arrive at a corpse soon after the
body begins to putrefy.
• In contrast to the flies, beetles have chewing
mouthparts and can manage tougher foods than the
semi-liquid material.
• The early arrivals tend to be predatory adults that feed
on fly larvae.
• There are over 200 species in this family, but the
ones that eat dead flesh are those that belong to the
subfamily Necrophorinae.

17. Rove Beetles
Family name: Staphylinidae
 They eat the fauna residing on and in a corpse.
 Adults are early visitors to a corpse and they feed
on larvae and eggs of all species of fly.
Hide Beetles
Family name: Dermistidae
 Late-arriving species tend to be specialist
scavengers which feed on tougher parts like
skin and tendons as the body dries out.

18. Determination of PMI
• PMI means Postmortem Interval (the time between
death and the discovery of the body).
• Determination of PMI is based on two major
principles:
1. SUCCESSION 2. LIFE CYCLE OF FLY

19. Calculating PMI from
Accumulated Degree Hours (ADH)
From To Temp Hours ADH Total
Egg 1st Instar 70° F 23 1610 1610
1st Instar 2nd Instar 70° F 27 1890 3500
2nd Instar 3rd Instar 70° F 22 1540 5040
3rd Instar Pupa 70° F 130 9100 14140
Pupa Adult Fly 70° F 143 10010 24150

20. Five Stages of Decomposition Fueled by
Insect Activity.
• Fresh
• Bloat
• Decay
• Post-decay
• Dry (skeletal)

21. 1.Fresh Stage
• Begins at death. Flesh flies, blow flies, ants
eating fly eggs and predatory wasps. First sign
of bloating due to putrefaction by anaerobic
bacteria.

22. 2.Bloat (Days 2-7)
• Swells due to gases Produced by bacteria.
• Temperature rise of the corpse
• Flies still present
Pig carcass in the bloat stage of
decomposition

23. 3.Decay (Days 5-13): • Gases subside,
decomposition fluids
seep from body.
• Bacteria and maggots
break through the skin.
• Predatory beetles such as
rove and hister beetles are
attracted
• Unpleasant odor
• Larvae beginning to
pupate.
• Corpse reduced to about
20% of it’s original mass.
Pig carcass in the decay stage
of decomposition

24. 4.Post-Decay (Days 10-23):
Pig carcass in the post-decay stage
of decomposition
Carcass reduced to hair,
skin, and bones.
Fly population reduced and
replaced by other arthropods.
Hide beetles are dominant
in dry environments.
Mite and predatory beetle
populations increase.

25. 5.Dry (Skeletal) (Days 18-90):
Does not always occur
especially if corpse is in a wet
region.
Maggots will stay longer and
hide beetles will not appear.
In wet environments the hide
beetles are replaced with
reduviid insects.
The corpse is reduced to at
least ten percent of the original
mass.
In the last stage (Skeletal
Stage), only bone and hair
remain.
Pig carcass in the dry/remains stage of
decomposition

26. Entomotoxicology is the analysis of drugs and toxins
on the development rate of carrion feeding insects.
Insect tissue or remnants are collected from
decomposing bodies and in their surroundings can be
used as alternate specimens for toxicological analyses,
when the blood, urine or internal organs are not
available.
In such badly decomposed bodies, fly larvae and their
remnants can also be used as a credible substrate for
toxicological analysis when poisoning is suspected.

27.  Fine paintbrush for collecting eggs and Spoons for collecting maggots.
 Fine and medium forceps (for collecting adults and the more fragile
immature insects)
 Hand net for catching flying insects
 Ethanol (70%) for storing dead specimens
 Protocol sheets for writing down what specimens were collected.
 Labels
 Vials and storage boxes of different sizes for preserving living and dead
insects
 Sawdust or tissue paper for handling eggs and living larvae in vials or
storage boxes
 Shovel and Robust plastic bags for soil samples and leaf litter
 Thermometer for measuring the body and ambient temperatures, as well
as the larval mass temperature
 Camera for photographic evidence.

29. Significance of Forensic Entomology
 The presence of insects on the body that are not found in
the area suggests the body was moved, and may indicate
the type of area where the murder took place.
 If the insect cycle is disturbed, it may suggest that the
killer returned to the scene of the crime.
 The entomologist may be able to estimate the date of death
and possibly the date of the return of the killer.
 If maggot activity occurs away from a natural opening, this
may indicate a wound. For example, maggots on the palm
of the hands suggest defence wounds.
 If maggots feed on a body with drugs in its system, those
chemicals accumulate and may be detected.
 If an insect is found from a specific site, it may place a
suspect at the scene of a crime.
 If insects are found on a living individual (often young
children or seniors), it may indicate neglect or abuse.

30. Limitations of Forensic Entomology
 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.
 Forensic entomology relies on insect abundance.
In winter, there are fewer insects and entomology's
use is limited.
 Since it takes time to rear insects, forensic
entomology cannot produce immediate results.
 Treatments (like freezing, burial or wrapping) that
exclude insects can affect estimates.

31. Conclusion
• Forensic entomology can make a highly effective
contribution to criminal investigations, but in
order for it to be of robust evidential value strict
protocols should be followed with regard to
collection and preservation of insect evidence,
subsequent analysis and reporting.
• Ideally this should be conducted by an
appropriately qualified forensic entomologist or
under the guidance of such.

32. References
• Journal of forensic dental science.
• B. r. Sharma, Forensic science in criminal
investigation & Trials.
• Dayananda, R. & J. Kiran, 2013. Entomotoxicology.
International Journal of Medical Toxicological
Forensic Medicine, 3(2):71-74.
• Dr Dorothy Gennard - Forensic Entomology_ An
Introduction-Wiley (2007)