HOSA Forensics: Entomology (10%)

entomology facts

insects colonize a body almost immediately after death in most cases ; their rate of development/ species dynamics can be used to accurately estimate the minimum time the person has been dead

entomology can be used

after 24-48 hours because that's when most medical parameters indicating time of death are complete

entomology can reveal

whether the body has been moved/ disturbed since death ; presence/ position of wound sites ; whether victim used drugs ; etc

blow flies

development of larval diptera (flies) over time

carrion insects

necrophagus insects ; depend on dead animal material to survive

venipuncture

(needle mark) blowflies can locate these where it is no longer visable to naked eye ; useful for homicide victims

first instar

first stage maggots ; feed on liquid protein, and molds into second instar

second instar

first instar larval cuticle and mouthparts are shed

third instar

second instar larval cuticle and mouthparts are shed ; eats a lot (voracious feeder)

adult fly

maggots pupate from instars to adult flies ; leaves behind hard dark puparial case which leaves evidence that it was there

blow flies facts

they're only attracted to fresh bodies

just a side note

the nearby environment is very important, as well as knowing what insects are native to the area

when killers try to hide the body

it usually takes killers sometime to decide where to hide the body ; during the decision time, blow fly eggs will colonize the body ; it is very difficult to remove all of their eggs from the original crime scene

killers return to scene of crime

they often try to disturb remains ; however, this disturbs the insects ; this helps determination of when the body was disturbed

locating wounds

find out maggot colonization on the body to determine where the wounds were

maggot activity in genital area

not an indicator of rape, because they will go their anyway for the mucosal layer

when drugs are involved and the body is not fresh

blow fly maggots are indicators to what drugs were in the body ; insects can bioaccumulate ingested chemicals into their body ; however, they can't tell amount of drugs, only type

insects & DNA

when the victim's DNA is no longer available, insects can be used to retrieve DNA ; as well as blood feeding insects, can be very helpful

myiasis

flies laying effs on a living person, maggots feed on dead material on the living person

entomology in abuse/ neglect

those who are colonized by maggots are incapable/ unwilling to look after themselves ; could be shown through dirty diapers and bed sores ; alcoholics/ drug users lose the will to care for themselves ; maggots can colonize the areas of the nasal septum that is destroyed when cocaine is snorted

MDT

maggot debridement therapy ; maggots could treat affected areas of bone