Entomology 101
This branch of science studies insects.
What is entomology?
These flies, including green bottle flies, are often among the first insects to arrive at exposed remains.
What are Blowflys?
What does PMI stand for?
Postmortem interval
Investigators preserve some collected insects in this liquid to prevent decay.
What is alcohol?
True or False: Insects are cold-blooded
True
This is the common name for a fly larva.
What is a maggot?
These are the most numerous insects on Earth and typically arrive after flies.
What are beetles?
Name the six stages of insect development commonly used in PMI
Egg → 1st instar → 2nd instar → 3rd instar → Pupa → Adult
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Material inside a maggot’s crop may contain this evidence that helps identify the person it fed on.
What is human DNA?
Near-freezing temperatures can explain why a body has few insects because cold has this effect on insect activity and development.
What is slowing them down?
These are the three main body regions of an adult insect.
What are the head, thorax, and abdomen?
This term describes changes in the insect community as a body decomposes.
What is insect succession?
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Using degree hours = temperature × hours, without subtracting a base temperature, calculate the degree hours accumulated during 10 hours at 20°C.
What are 200 degree hours?
How does temperature affect insect development?
Warmer = faster development; colder = slower development
What type of environment might delay insect colonization of a body?
Enclosed, buried, or underwater environments
This hard outer covering supports and protects an insect’s body.
What is an exoskeleton?
Large masses of maggots consume soft tissue most heavily during this decomposition stage.
What is active decay?
An emerging adult blowfly inflates this balloonlike structure on its head to help break open its pupal case.
What is the ptilinum?
This record tracks who collected, handled, and transferred insect evidence before it is presented in court.
What is chain of custody?
A large maggot mass produces its own heat. This is why investigators should measure its temperature instead of relying only on air temperature?
What is the maggot mass may be warmer than the surrounding air, causing larvae to develop faster.
These respiratory openings allow maggots to exchange gases while feeding.
What are spiracles?
Name the five commonly taught stages of decomposition in order.
What are fresh, bloat, active decay, advanced decay, and skeletal/dry remains?
Using degree hours = temperature × hours, without subtracting a base temperature, calculate the degree hours accumulated during six full days at 26°C.
What are 3,744 degree hours? (6 × 24 × 26)
Name two imaging technologies used to examine development inside a puparium without cutting it open.
What are high-resolution X-ray imaging and CT scanning?
Investigators estimate that larvae are four days old. Explain why this does not necessarily mean the person died exactly four days ago.
Insects may not have reached the body immediately after death. The larvae indicate time since colonization, which may be shorter than time since death.