The Role of Insects in Forensic Entomology

1. THE ROLE OF INSECTS IN FORENSIC
ENTOMOLOGY
Being a Term Paper Presentation (VMPE 800)
Presented to:
Staffs and Students of the Department of Veterinary
Parasitology and Entomology, Faculty of Veterinary Medicine
Ahmadu Bello University, Zaria.
By:
Akanni Azeez Olamide
(P13SCBS8070)
Lecturing Team: Prof. Natala
Dr. Ogo 1

2. WHAT IS FORENSIC ENTOMOLOGY?
INTRODUCTION
2

3.  Forensic Entomology is the use of the
insects, and their arthropod relatives
that inhabit decomposing remains to aid
legal investigations (Amendt et al, 2007).
INTRODUCTION
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4. SCOPE OF FORENSIC ENTOMOLOGY
INTRODUCTION CONT’D
4

5.  Medico-legal
 Urban
 Stored Product Insects
INTRODUCTION CONT’D
5
 Useful Insects in Forensic Entomology

6. HISTORY OF FORENSIC ENTOMOLOGY
INTRODUCTION CONT’D
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7. 7
INTRODUCTION CONT’D
 Early 13th Century
• Sòng Cí (Legal expert and Death Investigator’s
Report )
 13th – 19th Century
• Redi’s (1668) Experiment
• Linnaeus’ (1775) Development of Systematics
and Taxonomy
• Megnin’s (1894)Observation on Decomposing
Remains
 Stages of decomposition vs Speed vs
Environmental conditions

8. PRINCIPLES OF FORENSIC
ENTOMOLOGY
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9. PRINCIPLES OF FORENSIC ENTOMOLOGY
 Reliable information about;
•Insects Behaviour
•Growth
•Development
•Habit & Habitat
All of these gathered
over 2 and half centuries.
 Megnin’s Work on progressive stages of
decomposition (Insect Succession Method)
• Physical Changes of Decomposing Body
• Biochemical Changes and Insect Succession
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10.  What has been learned from the many studies on
insect succession is that the timing of the insect
groups can be variable given the following;
 Geographic location (which is a factor of
temperature)
 Season of the year
 Habitat
PRINCIPLES OF FORENSIC ENTOMOLOGY
 This insect succession method is used when remains
have been exposed for long periods of time, such as
for weeks or more
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11. PRINCIPLES OF FORENSIC ENTOMOLOGY
 This method can be very accurate, but not as
precise as the second method used for estimation of
the PMI.
Use of an Insect’s Known Growth and Development
Time
 Applied to the fly group (Diptera), but not
exclusively (Coleopterans can be used too)
 The underlying principle in using this method to
estimate PMI is that the blowflies (the gold standard
mostly used) will colonize immediately upon death 11

12. 12
PRINCIPLES OF FORENSIC ENTOMOLOGY
TABLE 1: Major family of flies (Dipterans) found on or near a carrion
Family Example Description
Calliphoridiae Blowfly (blue and green bottle flies)  Colonizes the carrion during early
stages of decomposition
 Often the most abundant larvae on
carrion
 Possess specific preference for
light intensity and temperature
being a poikilotherm.
Sarcophagidae Flesh Flies  Large in size
 Lays live larvae
 Larvae parasitizes blowfly maggot
 May also be present shortly after
death
Muscidae House Fly  Usually found during the last
stages of decomposition
Piophilidae Cheese skippers  Associated with late stage of
decomposition
Source: Self

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PRINCIPLES OF FORENSIC ENTOMOLOGY
TABLE 2: Different family of Coleopterans that colonizes a carrion
Source: Commons.wikimedia.org/wiki

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PRINCIPLES OF FORENSIC ENTOMOLOGY
Calliphoridiae: Caliphora vomitoria Sarcophagidae: Sarcophaga bercaea
Plate 1: Different groups/ families of insects that colonizes a carrion
Source:commons.wikimedia.org/wiki/Dipterans

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PRINCIPLES OF FORENSIC ENTOMOLOGY
Muscidae: Housefly Piophilidae: Cheese skipper
Plate 2: Different groups/ families of insects that colonizes a carrion
Source: Commons.wikimedia.org/wiki/Dipterans

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PRINCIPLES OF FORENSIC ENTOMOLOGY
Plate 3: Typical lifecycle of a blowfly /dipterans
Source:commons.wikimedia.org

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PRINCIPLES OF FORENSIC ENTOMOLOGY
Staphylinidae: (Rove Beetles) Silphidae: Carrion Beetles/Sexton Beetles
Source (1&2): Serajo and Michael K. Oliver, Ph.D

18. USES OF INSECT IN FORENSIC
ENTOMOLOGY
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19. 19
USES OF INSECT IN FORENSIC ENTOMOLOGY
 Estimation of Time Since Death/Post Mortem Interval
(PMI)
• The primary application of insects answering
questions in death investigation is to estimate when
the victim died (Rodriguez, 1989)
•This possibility exists due to the insects being the very
first organisms to colonize dead animals.

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Days after death House fly Blow fly Flesh fly Skipper fly
1 EGG LARVAE
2 EGG LARVAE LARVAE
3 EGG LARVAE LARVAE
4 LARVAE LARVAE LARVAE
5 LARVAE LARVAE LARVAE EGG
6 LARVAE LARVAE LARVAE EGG
7 LARVAE LARVAE LARVAE LARVAE
8 LARVAE LARVAE LARVAE LARVAE
9 LARVAE LARVAE LARVAE LARVAE
10 LARVAE LARVAE PUPA LARVAE
11 LARVAE LARVAE PUPA LARVAE
12 PUPA LARVAE PUPA LARVAE
13 PUPA LARVAE PUPA PUPA
14 PUPA PUPA PUPA PUPA
15 PUPA PUPA PUPA PUPA
16 PUPA PUPA PUPA PUPA
17 PUPA PUPA PUPA PUPA
18 PUPA PUPA PUPA
19 PUPA ADULT ADULT
20 PUPA
TABLE 3:Developmental stages of seral wave of flies that colonizes carrion and
their key indication of time of death.

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Temperature(oF)
House fly Blow fly Flesh fly Skipper fly
55o Delayed 4 Delayed 4.5 Delayed 4 Delayed 3
65o Delayed 4 Delayed 3 Delayed 2 Delayed 1
80o Accelerated 1 Accelerated 2 Accelerated 1.5 Accelerated 1
85o Accelerated 3 Accelerated 4 Accelerated 3 Accelerated 2
USES OF INSECT IN FORENSIC ENTOMOLOGY
Table 4: Various temperature ranges and their effects on development of flies
which may affect estimation of time of death.

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 Estimation of Location or Point of Death.
USES OF INSECT IN FORENSIC ENTOMOLOGY
• Another application of entomology is using the ranges
of a specific insect species’ geographic distribution
(where it lives) to establish from where a body
originated
• Case Study 1: California
• Case Study 2: Belgium

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 Identification of Area of Trauma in Extensively
Decomposed Body
USES OF INSECT IN FORENSIC ENTOMOLOGY
• Carrion insects (primarily blowflies) can be used to
identify areas of trauma on badly decomposed remains
when major changes have taken place in the
appearance of the soft tissues on the body

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 Entomotoxicology
USES OF INSECT IN FORENSIC ENTOMOLOGY
• The maggots may be used to determine the presence
or absence of drugs when human body tissues are too
badly decomposed to do toxicology on the tissue
remains
•Role of Chitin in trapping residue of controlled
drugs
•Case study 3: involving using puparial cases

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Identification of Suspect/Criminal
USES OF INSECT IN FORENSIC ENTOMOLOGY
• Techniques for analyzing molecular DNA structures of
insects for species identification and the human DNA in
insects that feed on humans have recently been
developed
• Case study 4: Rapist
• Maggots feeding on decomposing humans have been
tested for human DNA and found to retain testable levels

26. CONCLUSION
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 From the elucidated uses of insects in forensic
entomology above, it is obvious that forensic
entomology is an interesting aspect of entomology with
useful application to investigation and in aiding justice.
Despite the enormous usefulness, little or no work is
done in Nigeria and Western Africa as a whole,
therefore, I the justice department will be better
enhanced and the people better served if this branch of
science can be utilized.
CONCLUSION

28. THANK YOU FOR LISTENING!!!
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