Ch 5 effects on decomposition

8 effects on decomposition

1. geographic region

2. season

3. sun/shade exposure

4. buildings

5. vehicles

6. enclosed spaces

7. wrapping

Geographic Region

• species vary from region to region

• ecozone data varies, cannot be used for other region

Season

impact weather, temp, humidity, flora/fauna

• faunal composition/ grave chemistry affected by season

temperate regions- spring, summer, fall

*relative abundance: certain insects, differing colonization’s times could indicate season of death

Sun/ shade exposure

Direct sunlight= warmer, heat up +decompose faster

• mummify in regions w/ high temp

• progress thru stages faster

Buildings

• colonize just as easy as outdoors

• indoor vs outdoor=time of colonization

  • outdoor within minutes

  • indoor takes longer (limited access, delay decomp/colonization)

What flies found indoors/ outdoors

• blowfies readily enter homes

• flesh flies found only outdoors

• most fly larvae indoors

• beetle larvae= outdoor deaths

Vehicles (2 issues)

1. delay before insects can enter vehicle

   • windows open, vehicle designed

2. temp greatly increased

   • speed up insect dev./ decomp.

   • may compensate/ overcompensate for earlier delay

Enclosed Spaces

• garbage cans

• suitcases

• fridge/dishwasher

• limit insect access

  • prevent/ delay colonization by days

• insect use olfactory cues to gain entrance, doesn’t let them leave (dead)

Wrapping

• extent of wrapping affect colonization (delay/prevent)

• not impediment to colonization unless TIGHTLY sealed

• keep body protected, usually no evidence for entomologists

  • empty puparia, beetle exuvia, dead insides

exuvia

shed outer covering of insect during molting

• help identify stages/ PMI

Burial

• still colonized

  • influences: time required (longer), sqnce may not start w blowflies, fewer species involved, slower rate of decomp, lower soil temp

puparia

harden pupal case of an insect (flies) when larvae transform into adults

• used to estimate PMI