Forensic Entomology Unit 2 Section 2

Forensic Entomology The study of insects and their relation to a criminal investigation. Used to estimate time of death Blowflies are some of the first to infest the body – Usually within the first hour of death – Lay their eggs in moist areas of the corpse: nose, mouth, armpit, groin, and open wounds. – Lay eggs that hatch into maggots or fly larvae which eat human organs and tissue – For 6-10 days larvae feed, grow, and molt to become pupae

– Day 2: 5mm – Day 5: 17mm – Day 6-8: 12mm – Use length to determine time 12 days later adult flies emerge and the cycle continues Entomologists can determine how long the person has been dead by the stage of the life cycle the fly is in – Only eggs – less than 24 hours earlier – Fully grown maggots but no pupae – less then 10 days ago – Pupae – 6 – 10 or more days have passed – Adult flies – two to three weeks earlier ***See page 62 for life cycle

Types of flies found can help determine if the victim was killed at night or during the day – Some lay eggs in sunlight, some in the shade – Some types are found in the cold while others are found in the warm weather.

Factors that effect entomology Development can be affected by the weather Cold weather: blowflies are less common, maggots can go dormant for extended periods of time Warm weather: egg laying can occur faster A meteorologist may be consulted Can only provide a minimum time – Example: Pupae cannot appear in fewer then six days New generations of pupae can affect your results – Specimens are collected to observe the type of insects present, their stage of development, and how many development cycles have occurred.