Forensic Entomology. Application of the study of insects and their arthropod relatives to the legal system.

Transcription

1 Murder and Maggots

2 Forensic Entomology Application of the study of insects and their arthropod relatives to the legal system.

3 3 areas of Forensic Entomology Urban Entomology Legal proceedings involving insects and related animals that affect manmade structures and other aspects of the human environment.

4 Stored Product Entomology Insects found in consumer food products

5 Medicolegal Entomology Relates primarily to determining PMI and location of death Based on the sequential colonization of a corpse by insects and the developmental rates of their offspring

6 First case of insects solving a crime China 1235 AD Murder in a village Farmers gathered with sickles Forensic Entomology is born!

7 Popular Magazine s Top 10 WORST jobs in Science! 1. Hazmat Diver 2. Oceanographer 3. Elephant Vasectomist 4. Garbologist 5. Coursework Carcass Preparer

8 Popular Magazine s Top 10 WORST jobs in Science! 6. Microsoft Security Grunt 7. Gravity Research Subject 8. Olympic Drug Tester 9. Forensic Entomologist 10. Whale-Feces Researcher

9 Why use insects to estimate PMI? (post mortem interval) Arrive soon after death (often beat everyone to scene) Arrive in predicable patterns (communicates change with decomposition) Development is predictable (based largely on temperature)

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11 Common Species of Flies Eastern Golden Haired Blowfly Calliphora stygia is a large brown blowfly that is common and annoying in houses, and features regularly in insecticide commercials. It is one of the earliest flies to visit a corpse.

12 Australian Sheep Blowfly The Green-bottle, Lucilia cuprina, is a worldwide pest of sheep, imported to Australia from China. It is virtually identical to Lucilia sericata but occurs in drier areas. As well as laying in dead bodies and garbage tips, female Lucilia cuprina lay in parts of the fleeces of sheep that are contaminated with faeces and urine. The ammonia in urine is particularly attractive to the flies, and the young larvae can become established where the skin of the sheep has become irritated by the urine. These flies can then attack the living flesh of the sheep. Lucilia cuprina is one of the first flies to lay its eggs in a corpse, and the larvae are of the smooth form.

13 Female Green Hairy Maggot Blowfly Chrysomia rufifacies is a large, metallic green blowfly whose larvae are predaceous, feeding on the larvae of earlier-arriving flies. Adult females do not lay their eggs in a corpse until the body is partially decomposed and maggots are available as prey. The larvae of Chrysomia rufifacies have tough spiny skin, which gives them protection against other predators. The larvae pupate on the surface, rather than burrowing into the soil, and they are particularly vulnerable to parasitism by wasps.

14 Adult blowfly mouth Adult blowflies use spongy mouth parts to soak up fluids exuded from the body.

15 Structure of a Maggot Spiracles Mouth Hooks

16 Hairy Maggot Head

17 Mouth Hooks of a Maggot

18 Maggot Spiracles Maggot spiracles - The most distinctive feature for separating larvae of different instars is the structure of the posterior spiracles, though which the larvae respire.

19 A close up of one spiracle (breathing apparatus) of a fly maggot.

20 Identifying blow fly larval instars

21 Fly Eggs on a Dead Pig

22 Maggots (larvae) First instar

23 Maggots Third instar

24 Fly Pre-Pupa

25 Fly Puparia

26 Devil's Coach-horse Beetle Later colonizers are beetles

27 Mouth Parts of a Beetle

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29 Stage 1: The Living Pig

30 Stage 2: Initial decay - 0 to 3 days after death

31 Initial decay - 0 to 3 days after death

32 Initial decay - 0 to 3 days after death

33 Stage 3: Putrefaction - 4 to 10 days after death

34 Stage 3: Putrefaction - 4 to 10 days after death

35 Stage 4: Black putrefaction - 10 to 20 days after death

36 Stage 4: Black putrefaction - 10 to 20 days after death

37 Stage 4: Black putrefaction - 10 to 20 days after death

38 Stage 5: Butyric fermentation - 20 to 50 days after

39 Butyric fermentation - 20 to 50 days after death

40 Stage 6: Dry decay days after death

41 Stage 6: Dry decay days after death

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