foresnic entomology

7/28/2019 Foresnic Entomology

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An IntroductionForensic entomology is the study ofinsects and other arthropods in a

legal context. The applications arewide-ranging, but the most frequentis to determine the minimum time

since death (minimum post-morteminterval, or PMI) in suspicious deathinvestigations.


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This is done by identifying the age ofthe insects present on a humancorpse, which can provide a

Relatively precise estimate incircumstances where pathologistsmay only be able to give a broad

approximation.


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The fundamental assumption is thatthe body has not been dead forlonger than it took the insects to

arrive at the corpse and develop.Thus, the age of the oldest insects onthe body determines the minimum

PMI.


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Female (left) and male (right) adults of the

common bluebottle blowflyCalliphora vicina


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Two examples of this are:1. A body discovered in the summer insouthern England had suffered

extensive burns, making thepathologists interpretation of theconventional post-mortem changes in

the body very difficult. Ageing theblowfly larvae on the body indicated

that the first flyeggs had been laid on

the body six days before.


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Witnesses subsequently testifiedthat the fatal fire was observed onthe night before the estimated day

of egg-laying.


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2. A body discovered in late winter innorthern England was well preservedbecause of the cold temperatures, and

pathological evidence suggested thatthe person had died two to threeweeks before. In contrast, insect

evidence suggested that the personhad died more than two months

before the body was discovered.


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This was consistent with otherevidence and was accepted by the

coroners court.

Life cycle of a calliphorid fly (clockwise from bottom left):adults, eggs, first instar larvae, second instar larvae, third

instar larvae, puparia containing pupae


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*What is Forensic Entomology?Forensic Entomology is the use ofthe insects, and their arthropod

relatives that inhabit decomposingremains to aid legal investigations.The broad field of forensic

entomology is commonly brokendown into three general areas:medicolegal, urban, and stored

product pests.


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The medicolegal section focuses onthe criminal component of the legalsystem and deals with thenecrophagous (or carrion) feedinginsects that typically infest humanremains. The urban aspect deals withthe insects that affect man and hisimmediate environment.


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This area has both criminal and civilcomponents as urban pests may feedon both the living and the dead.

Urban pests are of great economicimportance and the forensicentomologist may become involved in

civil proceedings over monetarydamages.


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a) Forensic anthropology is th

application of the science of physicalanthropology and human osteology inlegal setting, most often in criminal cases

where the victim's remains are in thadvanced stages of decomposition.forensic anthropologist can assist in th

identification of deceased individualswhose remains are decomposed, burned,

mutilated or otherwise unrecognizable.
http://en.wikipedia.org/wiki/Physical_anthropologyhttp://en.wikipedia.org/wiki/Physical_anthropologyhttp://en.wikipedia.org/wiki/Osteologyhttp://en.wikipedia.org/wiki/Decompositionhttp://en.wikipedia.org/wiki/Decompositionhttp://en.wikipedia.org/wiki/Osteologyhttp://en.wikipedia.org/wiki/Physical_anthropologyhttp://en.wikipedia.org/wiki/Physical_anthropology


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Forensic anthropological technique

can be used in the recovery ananalysis of human remains.forensic analysis assesses the age, se

, stature, ancestry, and evidence foan estimate of the predominangeographical ancestry of th

individual, as well as determine if thindividual was affected by accidentaor violent trauma or disease prior t

or at the time of death.
http://en.wikipedia.org/wiki/Sex_differences_in_humanshttp://en.wikipedia.org/wiki/Staturehttp://en.wikipedia.org/wiki/Ancestryhttp://en.wikipedia.org/wiki/Race_and_geneticshttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Physical_traumahttp://en.wikipedia.org/wiki/Race_and_geneticshttp://en.wikipedia.org/wiki/Race_and_geneticshttp://en.wikipedia.org/wiki/Race_and_geneticshttp://en.wikipedia.org/wiki/Ancestryhttp://en.wikipedia.org/wiki/Staturehttp://en.wikipedia.org/wiki/Sex_differences_in_humans


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forensica,archaeologyForensicb)ofapplicationtheis,sciencetechniquesprinciples,archaeological

and methodologies in a legal context.)medicolegal(predominately

Forensic archaeologists are employedby police and other agencies to helplocate evidence at a crime scene usingthe skills normally used on

archaeological sites to uncover
http://en.wikipedia.org/wiki/Forensic_sciencehttp://en.wikipedia.org/wiki/Forensic_sciencehttp://en.wikipedia.org/wiki/Forensic_sciencehttp://en.wikipedia.org/wiki/Archaeologyhttp://en.wikipedia.org/wiki/Medicolegalhttp://en.wikipedia.org/wiki/Policehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Policehttp://en.wikipedia.org/wiki/Medicolegalhttp://en.wikipedia.org/wiki/Archaeologyhttp://en.wikipedia.org/wiki/Forensic_sciencehttp://en.wikipedia.org/wiki/Forensic_sciencehttp://en.wikipedia.org/wiki/Forensic_science


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c) Forensic pathology is a branch ofpathology concerned withdetermining the cause of death byexamination of a corpse. Theautopsyis performed by a coroneror medical examiner usuallyduring the investigation ofcriminal law cases and civil lawcases in some

d) Coroners and medical examiners
http://en.wikipedia.org/wiki/Pathologyhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Autopsyhttp://en.wikipedia.org/wiki/Coronerhttp://en.wikipedia.org/wiki/Medical_examinerhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Civil_law_(common_law)http://en.wikipedia.org/wiki/Civil_law_(common_law)http://en.wikipedia.org/wiki/Civil_law_(common_law)http://en.wikipedia.org/wiki/Civil_law_(common_law)http://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Medical_examinerhttp://en.wikipedia.org/wiki/Medical_examinerhttp://en.wikipedia.org/wiki/Medical_examinerhttp://en.wikipedia.org/wiki/Coronerhttp://en.wikipedia.org/wiki/Autopsyhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Cause_of_deathhttp://en.wikipedia.org/wiki/Pathology


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e) Forensic dentistry or forensicodontology is the proper handling,examination and evaluation ofdentalevidence, which will be thenpresented in the interest of justice.The evidence that may be derivedfrom teeth, is the age (in children)and identification of the person to

whom the teeth belong.
http://en.wikipedia.org/wiki/Examinationhttp://en.wikipedia.org/wiki/Evaluationhttp://en.wikipedia.org/wiki/Dentistryhttp://en.wikipedia.org/wiki/Evidencehttp://en.wikipedia.org/wiki/Justicehttp://en.wikipedia.org/wiki/Teethhttp://en.wikipedia.org/wiki/Teethhttp://en.wikipedia.org/wiki/Justicehttp://en.wikipedia.org/wiki/Evidencehttp://en.wikipedia.org/wiki/Dentistryhttp://en.wikipedia.org/wiki/Evaluationhttp://en.wikipedia.org/wiki/Examination


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This is done using dental recordsincluding radiographs, ante-mortem(prior to death) and post-mortemphotographs and DNA. Forensicodontology is derived from Latin,meaning forum or where legalmatters are discussed.
http://en.wikipedia.org/wiki/Radiographhttp://en.wikipedia.org/wiki/Photographhttp://en.wikipedia.org/wiki/Latinhttp://en.wikipedia.org/wiki/Latinhttp://en.wikipedia.org/wiki/Photographhttp://en.wikipedia.org/wiki/Radiograph


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he other type of evidence is that ofite marks, left on either the victim(by the attacker), the perpetrator

(from the victim of an attack), or onan object found at the crime scene.

ite marks are often found on

children who are abused.
http://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Child_abusehttp://en.wikipedia.org/wiki/Child_abusehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Crime_scenehttp://en.wikipedia.org/wiki/Crime_scene


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f) Forensic psychology is theintersection between psychology andthe justice system. It involvesunderstanding criminal law in therelevant jurisdictions in order to beable to interact appropriately withjudges, attorneys and other legal

professionals.
http://en.wikipedia.org/wiki/Psychologyhttp://en.wikipedia.org/wiki/Justice_systemhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Geographic_jurisdictionhttp://en.wikipedia.org/wiki/Judgehttp://en.wikipedia.org/wiki/Lawyerhttp://en.wikipedia.org/wiki/Legal_professionalshttp://en.wikipedia.org/wiki/Legal_professionalshttp://en.wikipedia.org/wiki/Legal_professionalshttp://en.wikipedia.org/wiki/Legal_professionalshttp://en.wikipedia.org/wiki/Legal_professionalshttp://en.wikipedia.org/wiki/Lawyerhttp://en.wikipedia.org/wiki/Judgehttp://en.wikipedia.org/wiki/Geographic_jurisdictionhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Criminal_lawhttp://en.wikipedia.org/wiki/Justice_systemhttp://en.wikipedia.org/wiki/Justice_systemhttp://en.wikipedia.org/wiki/Justice_systemhttp://en.wikipedia.org/wiki/Psychology


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An important aspect of forensicpsychology is the ability to testify incourt, reformulating psychologicalfindings into the legal language of thecourtroom, providing information tolegal personnel in a way that can be

understood.
http://en.wikipedia.org/wiki/Testimonyhttp://en.wikipedia.org/wiki/Testimony


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g) Forensic chemistry is the

application of chemistry to lawenforcement or the failure ofproducts or processes. Many different

analytical methods may be used toreveal what chemical changesoccurred during an incident, and so

help reconstruct the sequence ofevents.
http://en.wikipedia.org/wiki/Applied_sciencehttp://en.wikipedia.org/wiki/Chemistryhttp://en.wikipedia.org/wiki/Chemistryhttp://en.wikipedia.org/wiki/Applied_science


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"Forensic chemistry is unique amon

chemical sciences in that its research,practice, and presentation must meethe needs of both the scientific and th

legal communities. As such, forensichemistry research is applied anderivative by nature and design, and it

emphasizes metrology andvalidation."
http://en.wikipedia.org/wiki/Metrologyhttp://en.wikipedia.org/wiki/Metrology


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How diverse is forensic entomology?Here are a few examples: The diversapplications of forensic entomologinclude the detection of abuse in

children and neglect of the elderly.Published cases exist that detailparents intentionally using wasps and

bees to sting their children as a forof punishment.


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Additionally, entomological evidenc

has been used to prove neglect andlack of proper care for woundsexisting on the elderly under both

private and institutional care.


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It is theorized that the stings (or mer

presence) of bees and wasps may bresponsible for a large number osingle occupant car accidents that

seem to lack a definitive cause. Somaccident studies have shown insects tobe within the top 20 causes o

automobile accidents.


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In addition to automobile accidents,

insects have been suspected of causinaircraft crashes through thobstruction of essential

instrumentation,

and even implicatedin the obstruction of fuel lines causinengine failure. Forensic entomologists

are also requested to examine thfragmented remains of insects thathave impacted and lodged on the front

fascia, windshield, and radiator o


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Information about the development-1

and appearance of some commonforensically important insects.

.BeetlesorfliesBlowthetodirectlyGo

Insects have existed on earth foabout 250 million years;comparatively humans have existed

for about 300,000 years. Such anenormous amount of time has allowedinsects to attain a wide diversity inboth form and develo ment.
http://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htmhttp://www.forensicentomology.com/appear.htm


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There are currently about 700,000

described species and it is estimatedthat there may be more than 10million species of insects yet to b

described. Some insects have evolvea gradual or "paurometabolous"development in which there is an eg

that hatches into an immature o"nymph", which resembles the adultform, but is smaller and lacks wings.


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In the forensically important insects,

this is best represented by thmostHowever,.cockroaches

forensically important insects

undergo a complete o"holometabolous" development.There is an egg stage (except for a fe

thafliesfleshtheassuchinsectsdeposit living larvae) which hatchesinto a larval form and undergoesste wise or incremental rowth. This
http://www.forensicentomology.com/roach.htmhttp://www.forensicentomology.com/rts.htmhttp://www.forensicentomology.com/rts.htmhttp://www.forensicentomology.com/rts.htmhttp://www.forensicentomology.com/rts.htmhttp://www.forensicentomology.com/rts.htmhttp://www.forensicentomology.com/roach.htm


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This pattern is caused by th

successive molts (shedding of thouter skin that has become too small)that the larva must undergo before it

finally enters the inactive pupal stage.The pupa is simply the hardened outeskin of the last larval stage and th

adult will develop inside of thisprotective skin.


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Blow flies

In the insects that undergo completdevelopment, the larval stages appeaquite different from the adult form.

The larvae of flies (order Diptera) thatare commonly recovered fromdecomposing human remains lac

functional legs, and the body of manspecies appears cream colored, soft-bodied, and quite "maggot-like".


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For a picture of some of the maggots

commonly found on human cadavers.Once the larva or "maggot" is throughfeeding it will migrate away from th

corpse in order to find a suitable sitto form the pupal stage.


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This pattern is caused by th

successive molts (shedding of thouter skin that has become too small)that the larva must undergo before it

finally enters the inactive pupal stage.The pupa is simply the hardened outeskin of the last larval stage and th

adult will develop inside of thisprotective skin.


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Beetles

The beetles (order Coleoptera) arone of the largest groups of animalsand they also undergo complet

development. Because of theidevelopment the larvae appear verdifferent from the adult form.

Although the larvae or "maggots" oflarge number of blow fly species malook almost identical;


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the larvae of beetles may look ver

different from one species to the next.Beetle larvae recovered from corpsescan be easily differentiated fro

maggots as they have 3 pairs of legsand the maggots found ondecomposing remains will not hav

any legs.


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Once a larva as been identified as that

of a beetle, further field identificationcan be accomplished because of thwide diversity of larval forms. Th

bodies of beetle larvae may rangfrom almost white, robust, andhairless to dark brown, slender, and

quite hairy. Others may appear almostblack and have armored plates ontheir back.


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For a picture of some of the most

common beetle larvae. Although thnumber and appearance of adultbeetles that can be found on human

remains is much too diverse to shoeven a representative sample.


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resulting in a succession of Insectsarriving at the body, but as they tendto arrive after the blowflies, they are

less useful in establishing a PMI.


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blowfly infestations of human bodies

Are a natural outcome of the fliesrole in the environment as primarydecomposers. The ubiquity of fly

larvae on carrion is clear to anyonewho comes across the dead body of ahedgehog or rabbit while walking inthe country.

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