Module 8: Forensic Entomology

Question 1

Factors affecting decomposition rate

Answer 1

• age (middle age decompose slower) (young quicker than old)
• size (overweight faster; fat hasten decom)
• clothing (less exposed, slower)
• health (sick faster)
• environment ( high temp & humidity, faster)
• location (faster in air, slow in water and soil)

Question 2

Name the 5 stages of decomposition

Answer 2

• Fresh
• Bloat (Putrefaction)
• Active decay (Black Putrefaction)
• Advanced decay
• Skeletonization

Question 3

Fresh description

Answer 3

• autolysis
• no physical changes
• begins right after death up to next 2 days
• first flies
• body and environment temp equilibrium
• mortises

Question 4

Bloat (putrefaction) description

Answer 4

• around day 4
• leaking enzyme ->gases ->expanded abdomen
• sulfur compound -> skin discoloration
• purging
• mabaho
• peak number of flies

Question 5

Active Decay (black putrefaction) description

Answer 5

• around day 6-10
• lumiit na tiyan
• maggot feeding -> loss in mass
• skin turning black
• maggots leaving -> end of this stage

Question 6

Advanced decay

Answer 6

• around day 10-20
• begins to dry
• most flesh is gone (skin, cartilage, bone)
• mostly beetles
• possible adipocere formation/grave wax

Question 7

Skeletonization

Answer 7

• day 50 onwards
• skeleton
• few beetles, some mites

Question 8

Forensic Entomology

Answer 8

study of insects in relation to criminal investigations

Question 9

True or False
Ancient times don’t know association of decomposing bodies and insects

Answer 9

False

Question 10

Who disproved spontaneous generation theory?

Answer 10

Francesco Redi

Question 11

True or False
Life cycle of species have known time intervals

Answer 11

True

Question 12

Blow Fly Life Cycle

Answer 12

• Eggs - found in warm and moist area of a corpse in less than 8hrs.
• LS 1 (instar 1) - within 23hrs
• LS 2 (instar 2) - 2 days postdeath
• LS 3 (instar 3) - 3 days postdeath
• Pupa - about a week postdeath
• Adult - about 2 weeks postdeath

Question 13

True or False
Different species colonize at the same time

Answer 13

False

Question 14

Succesion of beetles

Answer 14

Blow flies ->Flesh flies-> Clown Beetles - >Carrion Beetles -> Dermestidae Beetles
(Sequence is predictable, but timings will differ.)

Question 15

True or False
Life stages of insects can help determine/estimate PMI

Answer 15

True

Question 16

Types of insect evidence

Answer 16

• presence of insects on the body
• developmental stages of insects
• insect artifacts ( feces, pupal cases)

Question 17

Importance of FE

Answer 17

• evidence
• estimate PMI
• was the body moved?
• locate clandestine graves or crime scenes
• locate wounds concealed by decom
• detect presence of drugs

Question 18

Techniques in FE

Answer 18

• collect and preserve of insect evidence
• rearing insects to determine life cycle
• molecular techniques for species ID
• statistical models for PMI estimation based oon insect evidence

Question 19

What do you need to know in when conducting FE?

Answer 19

• species
• stage of development for the specific species
• standards for development timings
• temperature and precipitation history

Question 20

Why do you need temp and ppt history?

Answer 20

Sometimes insects were washed away.

Question 21

Challenges in Forensic Entomology

Answer 21

• envi. factors affect insect activity
• lack of standardization in FE techniques
• limited understanding of insect behavior in different environments.

Question 22

Future Directions in FE

Answer 22

• advances in DNA analysis for ID species
• development of more accurate model for PMI estimation
• integration of entomological data with other forensic disciplines.