Forensic Entomology Notes on page 79 What is

Forensic Entomology Notes on page 79

What is Forensic Entomology? § Applying the study of insect life cycle to estimating time of death § Flies and beetles follow a life cycle that allow scientists to estimate how long a body has been deceased

Life Cycle of the Fly 21 -24 days 8 -12 days Soon after death 4 -5 days 1. 8 days 2. 5 days

The egg § Shortly after death, a mature fly will lay eggs on the decomposing flesh § Will typically lay eggs in moist, warm areas § Mouth, eyes, ears, anus, wounds § Will remain 8 hours § Approximately 2 mm in length

Larval stages § § § Also called instar 1, 2 and 3 Have black mouth hooks Will have spiracle slits near anus § Instar 1: 1 spiracle slit; 5 mm in length § Instar 2: 2 spiracle slits; 10 mm in length § Instar 3: 3 spiracle slits; 17 mm in length § Crop visible in 2 nd instar stage; covered by fat deposits in 3 rd instar stage

Maggots

Pupa stages § After 3 rd instar maggots have matured, they will crawl away from body to a dry area § Become immobile, do not eat, changes to a dark brown color, pupa case is hard § Can stay in pupa cases for 10 -16 days

Adult flies § Adult fly matures in approximately 21 -24 days § They will be alive for several weeks § Not able to fly in first couple of hours

Beetles § Beetle larva differ from maggots in that they have 3 pairs of legs § Arrive on body after flies lay eggs § Come to feed on the maggots

Question § Answer this question on page 78 § Explain how flies and maggots are used to help estimate the time since death of a decomposing body