Forensic Entomology
FSC 462-662
Dylan Parry
Insect Ecologist Background: Dual PhD, Dept. of Entomology and Program in Ecology &
Evolutionary Biology from Michigan State University)
MS in Entomology (University of Alberta)
What is Forensic Entomology?
l  Application of insects to legal issues.
l  Several categories, for the most part, I’ll be talking
about medicocriminal forensic entomology.
l  Arthropods associated with crimes
l  Usually violent crimes such as murder, suicide, and rape,
l  Physical abuse and contraband trafficking.
l  Death investigations
l  Establishing timelines (time since death to time of discovery
(postmortem interval or PMI)
l  Movement of the corpse, manner and cause of death.
l  Association of suspects with the death scene
l  Detection of toxins or drugs → insect larvae
Brief History
l
l
l
Sung T’zu (1235)
l
First reference to forensic entomology
l
Use forensic entomology to solve a case of a long-dead
infant
Bergeret (1855)
Megnin (1894)
l
l
l
l
“La Faun des Cadavres: Application l’entomologie a la
Medicine Legale”
Hall 1948
l
Monograph on identification of blowflies
l
Rekindled interest in the technique, published series of
case histories
Nuorteva (1970’s)
Keh (1985), Smith (1986), Catts and Goff (1992)
l
Textbooks and reviews
Stages of Decomposition
l
A. Fresh Stage (Days 1-2)
l
l
B. Bloated Stage (Day 2-6)
l
l
Abdominal wall breaks allowing gasses to escape. Carcass
deflates.
D. Post-decay Stage (Days 10-25)
l
l
Putrefaction begins. Gasses produced by anaerobic bacteria
inflate the abdomen.
C. Decay Stage (Days 5-11)
l
l
Commences at death, ends when bloating is first evident.
Breakdown of protein and carbohydrates into simpler compounds
In dry habitats, remains are skin, cartilage, and bones. In wet
habitats, wet, viscous material in the soil under the remains.
E. Dry Stage (Days 25+)
l
Mainly bones and hair remain. Odor is primarily that of normal
soil and litter. Can last several months to years.
Functional roles of Insect Associates
of Cadavers
l
l
l
l
Obligate necrophages – examples, blowflies, some
beetles
Facultative necrophages – ants, cockroaches, some
flies, some beetles
Natural enemies of necrophages – yellowjackets, ants
Adventives – accidental species with no actual feeding
relationship with cadaver
Omnivores
“Oh my!...What a cute little
maggot!”
Predators /
Parasites
Necrophages
Adventives
Succession
A cadaver is a very rich but ephemeral resource
l  Competition intense among organisms, especially
in the early stages of decomposition.
l  Insect colonization of a corpse occurs in a
series of stages.
l
l
l
Different groups are adapted to different
decompositional stages of a corpse.
Thus, there is a fairly predictable sequence of
colonization
Major Groups of Necrophagous
Insects Associated with Cadavers
l
Flies
l
l
l
l
l
Early: Blowflies
Early: Flesh Flies
Early: House Flies
Late: Cheese Skippers
Beetles
l
l
Early/Mid: Carrion Beetles
Late: Dermestids
Succession and Decomposition
Khloe and Kim Kardashian
Snooki
“Paris”
Why Pigs?
Omnivorous
l  Physiologically similar
l  Hairless
l  Similar morphology
l
Succession
Fresh
1
Decay
4
2
Post-Decay
5
Bloated
3
Dry
6
Fresh Stage
l
l
Blowflies have detected the cadaver
Eggs are being laid, often around the eye,
nostrils, mouth, followed by anus or genital
openings
Eggs
Bloated Stage
l
l
l
l
Cadaver begins to swell and putrefy
Blowflies are still ovipositing
Flesh flies appear
Small maggots are feeding
Small
maggots
Flesh fly
Pig’s eye
Decay Stage
l
l
l
Adult blowflies no longer attracted.
Large masses of maggots feeding externally
and internally
Predators and parasitoids on maggots arrive
Post-Decay Stage
l
Cadaver is drying out. Large maggots are
leaving or have left
Dry Stage
l
l
Skin and bones
Insects with
the ability to
digest keratin
(clothes moths
and dermestid
beetles).
Housekeeping
l
l
l
l
l
Course Page
http://www.esf.edu/efb/parry/fsc 462_662_Home.htm
I will post all lecture/lab material as PDF’s which you can
download or read online.
I also use the page to post other material to accompany
lectures / labs
I don’t use Blackboard