Presentation is loading. Please wait.

Presentation is loading. Please wait.

How the little critters can help

Similar presentations


Presentation on theme: "How the little critters can help"— Presentation transcript:

1 How the little critters can help
Forensic Entomology How the little critters can help

2 Insects are predictable
Because we can observe the behavior of insects, we can establish a timeline that can indicate approx. time of death First, the general effect of time on a body: Fresh: immediately following death and before bloating. Bloated stage: gases produced by decomposition within the body cause it to swell. Active decay: larvae penetrate the abdomen, causing deflation Advanced decay: majority of internal tissue lost, other internal elements beginning to liquefy. Dry remains: soft tissue lost, leaving skin, bone and cartilage.

3 It’s hard to establish an exact time that is standard
Climate concerns: Temp Moisture Location Types of indigenous insects differ area to area

4 General Life Cycles are Important
Egg Larva Pupa Adult Predictable times

5 Other insects Dermistids Roves Silphids Scarabs
Skin Beetles Carrion Beetles Late Stages

6 Points of interest: Myiasis=> Where maggots feed on living material
Dermistid Beetles used to clear flesh from skeletons

7 Some limiting factors:
Time of day- Flies don’t lay eggs at night Geography Different climates- different insects Season Especially in N.E.(Temperate zones) Microclimate Was the body in the sun? Habitat Urban locations vs. City

8 Bodies in buildings Burial Bodies in water Wrapping
Different accessability Greater flies, less beatles Burial Denies surface access (flies) Bodies in water Submerged- only aquatic insects Partial- flies & aquatics Wrapping Could restrict access of some Flies access anyway

9 Scavenger activity Burning Actually doing same job macroscopically
Alters A LOT Where, how, insects Burning High temps offset normal measures Cracked skin allowed easier access Body NEVER entirely consumed

10 In Summary: Insect determination is a science that must be known only by investigation in that region Many variables must be controlled Predictable but must establish COMPARISION How is this done?- Experimentation!!


Download ppt "How the little critters can help"

Similar presentations


Ads by Google