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Forensic Entomology. Bud and Patti Bertino. Forensic Entomology is based on:. Insect life cycles Knowledge of length of stage of development Predatory food chain on corpse Gases produced by decomposing bodies draw insects, not blood
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Forensic Entomology Bud and Patti Bertino
Forensic Entomology is based on: • Insect life cycles • Knowledge of length of stage of development • Predatory food chain on corpse • Gases produced by decomposing bodies draw insects, not blood • These gases are carbon dioxide, methane, ammonia and nitrogen
A first ‘wave’ of insects • Usually blow arrive first laying 150-300 eggs on soft tissue lining body openings on corpse • In 1-2 days, eggs hatch and maggots feed on corpse (1st instar stage)
Maggots mature through 3 instar stages before forming a cocoon (pupa stage) • About a week later, adult flies emerge
What might effect the accuracy of the time sequence of the life cycle of the blow fly?
Second wavecould include: • Beetles or other insects who feed on blow flies and have a life cycle of their own • The corpse may really be the origin of a food chain. How does a food chain work?
How would each of these factors affect time of death estimations? • Burial • Immersion in water • Mummification • Geographic location
Temperature & Humidity • Light & Shade • Season • Length of day • Manner of death (Poisons may slow down decomposition)
Project ideas: • Study the life cycle of a blow fly and determine the timeline used by forensic scientists. • Obtain some liver and grow your own ‘time line’. • Search the internet for crimes that were solved through the use of forensic entomology.