Exam 3
Gold Standard for toxicology
Gas Chromatography-mass spectrometry (GC-MS)
Which of these is the largest beetle family?
Scarabidae
What is the rule of thumb for decomposition rate of buried bodies vs. exposed bodies?
1 week in air = 8 weeks underground
By convention, what is the lower threshold for warm weather fly species (green bottle flies, etc.)?
20 C
Using a threshold temperature of 400 F, if the low was 350 F and the high was 680 F how many degree days accumulated over 2 days?
23
Approximately how long should you leave a temperature unit at the scene after a body has been found?
3-7 days
0-3 hours fresh
Autolysis begins on the inside
What causes adipocere?
Bacterial enzymes convert unsaturated fats into saturated fats
Coleoptera
Beetles 350,000 species Largest order
A flyʼs lower threshold is 6 degrees. The low for the day was 25 degrees, and the high was 45. How many degree days accumulated?
29
How many seres did Megnin identify on an buried body?
3
Very young larvae first feed:
Between muscles and muscle fibers
Where do fly larvae feed during the fresh stage of decay?
Between the muscle fibers until the acid is broken down
Which family is characterized by the first abdominal sternite divided by the hind coxae?
Carabidae
Silphidae are commonly called:
Carrion or sexton beetle
Secondary consumers
Consumes the primary consumers
Since geographical region has a major effect on arrival times of different species of insects to dead bodies, what do you know?
Data generated in one region or biogeoclamatic zone should not be used to determine time of colonization in a different region
According to your reading, the onset of _______ is considered to begin when gasses escape and the remains become deflated.
Decay
Putrefaction
Decomposition of body tissues.
Which myiasis causing fly may die after its host dies?
Dermatobia hominis
Food web
Describes the interactions between organisms and recycling energy. -Trophic level
How does a lethal dose of cocaine affect maggot development?
Development is accelerated
The seres identified by Megnin in buried bodies consist of which insects?
Diptera, Staphylinidae, root eating beetles
Parasites
Do not consume the whole prey item. Feed on the organism.
The ______ stage of decomposition is characterized by the reduction of the corpse to skin, cartilage, and bones, according to your reading.
Dry
When do ectoparasites leave a decaying body (when that body is on the ground)?
During algor mortis
According to lecture, where are drugs NOT commonly found in Diptera?
Eggs
What is a definition of death?
Irreversible cessation of circulatory and respiratory functions.
How is the soil under a body affected during the bloated stage of decomposition.
It tends to become alkaline
How does morphine affect larval development?
Maggots are larger and the pupal period is longer
Of the following flies, which would you expect to find in a buried coffin?
Megaselia scalaris
Which of these is a species of Phoridae?
Megaselia scalaris
When you take soil samples, what are you looking for?
Pupae and maggots mainly, and any other insects you may find
What does TSP do for a preserved larvae?
Re-hydrates the tissues
When does the postmortem clock begin?
Right after death
What is the standard for the determination of human nuclear DNA profiles?
STR analysis
Which category of organism is most important for time of colonization estimation?
Sarcosaprophagous species
A cow belongs to which trophic level?
Secondary trophic level
Blending waves of arthropods, each comprised of different organisms are called:
Seres
"Coloeoptera" literally means:
Sheath winged
STR stands for:
Short tandem repeats
Silphidae 2 sub families
Silphinae Nicrophorinae
A body in water initially:
Sinks
Why do insects need to be quickly killed and preserved if gut content studies are necessary?
So the insect won't digest the evidence
Staphylinidae
Staph beetles Rove Beetles; Coleoptera
Paederus sp. is in what family?
Staphylinidae
Which maggots are most important during your search at the scene?
The largest--you want to find the oldest maggots
The largest maggots in a mass usually represent:
The oldest maggots
livor mortis
The pooling of the blood in tissues after death resulting in a reddish color to the skin fizxed within 12 hours. -Potassiu chlorate- Brown lividity.
What is the field of ecology?
The study of the interrelationships of an organism and its environment
What happens when maggots are preserved in isopropyl alcohol?
The tissues turn black
You see a fresh body with small, first instar maggot masses in the mouth, eyes, and in the chest muscles. What do you know?
There was a wound in the chest
Why do we think that there is limited information on gut content in Sarcophagidae and Muscidae?
They are less important at the moment to forensics
What type of insects are attracted to dry decay?
Those that can feed on hair and dried skin
Which situation seems to most dramatically affect insect succession on bodies?
Tight, extensive wrapping
Why do you boil a maggot before you place it in ethanol?
To break down the waxy cuticle
Why do you need to note where maggot masses are found on the body?
To identify possible injury sites
What is a degree day?
Total degrees of heat above lower threshold accumulated in one 24 hour period
Environment
Total of circumstances surrounding a group of organism with extrinsic system and affects the organism (physical factors that affect growth, development of the organism. Includes biotic and abiotic factors.
What trophic level do Calliphoridae maggots fall into?
Transformers
Frass
Unbroken waste material mummified remains
Where are rove beetles most commonly found?
Under rocks, logs, carrion or dung
Adventive species
Use carrion as an in an area and offers something it can live without.
When do adult silphidae show up at carrion?
Usually within the first 24 hours after death
Why do you need to check the area around the body?
Wandering maggots
Adipocere
Waxy fat; happens with bodies under water -Happens when buried
Primary consumers
eats a plant
Chrysomelidae
leaf beetles
Cerambycidae
long-horned beetles
Rigor mortis
stiffness of the body that sets in several hours after death
Megaselia scalaris
technical name for phorid fly: Blow fly
A flyʼs lower threshold is 11 degrees. The high for the day was 15 degrees and the low was 5 degrees. How many degree days accumulated?
0
Megaselia scalaris is in which family?
Phoridae
Which family contains the coffin flies?
Phoridae
Which family contains the scuttle flies?
Phoridae
How do you preserve maggots at the scene?
Place them in hot water then in 80% ethyl alcohol
Which substance may be used to "clear" a maggot?
Potassium hydroxide
Egg breaker
Pressure to an eggshell weakness and the larvae is able to feed
Bamboo belongs to which trophic level?
Primary trophic level
Phoridae
Holometabolous
Buprestidae
metallic wood-boring beetles
Active Decay 10-20 days (blac putrefaction)
-Bloated body collapses -Black in coloration -Large volumes of liquid leaving the body -Insect activity is apparent -Skin slippage -Gloving is occurring
putrefaction (4-10 days)
-Buildup of gases, bloating of the abdomen, beyond livor mortis/ It is because of hemoglobin being breakdown. -Purging of liquid
Autolysis
-Cells just burst open, leaking out, hemostasis ends. -Anything that requires energy stops. -Autolysis is the same process as digesting, not active digestion. No energy to facilitate digestion. -Instead, the cells are using their lysosomes. -Release their digestive enzymes into the cell and leaks out into cytoplasm. -Happens first in the pancreases, stomach and liver. -Any digestive juices will degrade.
Gas chromatography-mass spectrometry (GC-MS)-
-Combines the mass spec and gas chromatography. -The seporate column is then move to the mass spectrometer, captures and ionized. -Can tell the chemical properties. -The gold standard for toxicology
Dry Decay 50-365 days
-Decay can happen slowly -Body is as long as fur/hair remain -Dependent of species
Heroin
-Faster development and larger maggot size
Skeletonization
-Hair removed-skeletal -Can take years
Methamphetamine
-Larval develop quickly -Pupal death is high -Could not reproduce
Morphine
-More rapid development and larger maggots, not dependent on doses -Error up to 29 hours
Pesticides
-Parathion -Malathion
-Amitriptyline(antidepressants)
-Post feeding and pupal stage (long time) -No other difference -Larval death common -Under estimation PMI
Cocaine
-Show differing developmental time. -Sub lethal doses- Develop the same rate -Lethal levels-Will develop larval stages, larger maggots, but no change pupal
Butryic fermentation 20-50 days
-Smells like parmesan cheese -Mold occurs
By convention, what is the lower threshold for warm weather fly species (green bottle flies, etc.)?
10 C
You find a body on very smooth terrain. Approximately how far do you expect the maggots to wander from the body?
100 ft
12-12-12 rule
12 hours to appear 12 hours to last 12 hours to go away
A flyʼs lower threshold is 10 degrees. The average temperature for the day was 25 degrees. How many degree days accumulated?
15
You find a body in very rough terrain. Approximately how far away do you expect maggots to wander from that body?
15 feet
Calliphorid colonization of bodies buried a few feed under ground is delayed by approximately how long?
2 Weeks or more
Calliphorid colonization of bodies buried a few feed under ground is delayed by approximately how long?
2 weeks or more
According to lecture, approximately how many Phoridae are there in the world?
3500
Scuttle flies species
3500
Ceridae
3500 species
Phoridae
3500 species world wide -Scuttle fly -Coffin flies -Humpback
According to lecture, when are male M. scalaris receptive to mating?
4 days after eclosion
Muscina stabulans finds bodies buried how deep?
40 cm
Fannia will limit their burrowing to find a body to:
40cm
How many dead, preserved maggots should be collected from a body?
50-60
By convention, the lower developmental threshold for cold weather or winter flies is:
6 C
How many seres did Megnin identify on an exposed body?
8
Tache noire
A brown to black band of discolored sclera of the eye. Created by the postmortem drying of the sclera by the air. Drying of the eyes
Who is in charge of the crime scene (generally)?
A detective
An insect that has a life cycle that involves being a parasite during the larval stage but is free living during the adult stage is called:
A parasitoid
Parasitoid
A specialized type of predator that lays eggs inside other organisms - referred to as its host -A parasite in one stage of its life.
You find an insect with an upper thermal limit of 60 C and a lower thermal limit of 24 C. Where did it most likely evolve?
A very warm or tropical area with high temperatures
That dragonfly that I found in the car at a crime scene...which ecological category does it fall into?
Accidental species
Predatory maggots are more abundant at which stage of decay?
Active decay
Ecosystem
Biological community with the physical environment, biological unit, in which captures and cycles energy. Closed system.
Where should temperature be taken at the scene?
Body temp, maggot mass temp, under body temp, ambient temp, and ambient temp several days after
What decomposition al stage is characterized by a "cheesy" smell?
Butyric fermentation
According to your reading (and Erzinclioglu 1996) which species of fly preferred decomposed remains to fresh when given a choice?
Calliphora vicina
Why is Spanish Fly known as a aphrodisiac?
Cantharidin causes priapism
Carbon monoxide poisoning causes what color livor mortis?
Cherry red
Histeridae
Clown beetles 3000 beetles 500 in N. America Black sometimes green
What flies do you expect to find a body buried 6 feet under ground?
Coffin flies
The forewings in Coleoptera are called:
Elytra
Smallest fly in the world
Euryplatea nanknihali
Omnivores
Feed on carrion and the inhabits of carrion.
Sarcosaprophagous
Feed specifically on decaying meet
How does wrapping a body affect decomposition rate?
If it's warm, it may speed up the decomposition, if it's cold and keeps the elements and insects away it may retard decomposition
What is the best way to kill a mosquito you wish to use for gut content analysis?
In the freezer
According to your reading, what are typically the first insects to discover a body after death?
Insects
Where do you go to get officially certified weather data?
NOAA
Which insect guts are currently most useful for forensic entomology?
Necrophagous and ectoparasite guts
Accidental species
Not attracted to the carrion in any way and just happened to be there.
Where are the majority of maggots found on a hanged body?
On the ground underneath the body.
When trying to reach a buried body, where does Muscina stabulans lay its eggs?
On the soil surface
What is the rule of thumb for a degree day?
One degree day happens when the average temperature for the day is 1 degree over the lower threshold
Predators
Organisms that feed on whole other living organisms (killing it in the process)
Approximately how many species of Silphidae are there?
Over 1500
Phoridae larvae feed on:
Particles of organic matter suspended in fluid
The genus Paederus have a toxin in their blood which cases dermatisis. This toxin is called:
Pederin
The characteristic frass of the dermestid beetle is formed from:
Peritrophic membrane
Producers
Sunlight to sugar (photosynthesis) -Grows very fast. -Plants are producers
One of the most important density independent factors for insects is:
Temperature
radioimmunoassay
Test combines radioactive chemicals and antibodies to detect minute quantities of substances in a patient's blood.
What is the major concern with collecting maggots from an autopsy?
The body was probably in cold storage
Butyric fermentation is most suitable to the mouth parts of which insects?
The chewing mouth parts of beetles
What is algor mortis?
The cooling of the body after death
The two most important bits of information for forensic entomology are:
The insects and the weather data
peritrophic membrane
What structure protects the midgut from abrasion by food particles and acts as a sieve? Allows waste material to be wrapped in the lining. -Completely wrap up their food and send it out as waste material.
Gas Chromatography
a method of separating chemicals to establish their quantities
thin layer chromatography TLC
a separation technique that involves the separation of small molecules as they move through a silica gel
Tenebrionidae
darkling beetles
Necrophagous
feeding on carrion
Saprophagous
feeding on decaying matter
Carabidae
ground beetles
Carabidae
ground beetles 4000 species
Culcidae
mosquitoes
Scarabaeidae
scarab beetles dung beetles 19000 species 14000 in N. America
What is algor mortis?
the cooling of the body after death
Curculionidae
weevils, snout beetles