Module 5 Flashcards
Carbon Nitrogen and Phosphorous
Nutrients that are cycled between plants and other organisms
Molecules are absorbed by producers and uptake is done by consumers
Decomposers
Break down molecules into simpler compounds and return them to the atmosphere soil or water
Important to replenish what is used by primary producers
Detritivore
Internally breakdown dead organic waste
Physically shred waste
In warmer environments they breakdown more things because they are more active
Insects and arthropods are detritivores
When detritivores feed on the same type of waste they can be grouped into
Feeding guilds
Cellulose
A large sugar molecule and the most abundant carbohydrate
Insects use cellulose by consuming wood
Name for insects that use cellulose
Xylophages
most feed on dead wood but can cause damage to man made structures
How do xylophages break down cellulose
Symbiotic relationships with gut microbes to break it down or making cellulose breaking down enzymes themselves
Cellulose is broken down into
short chain fatty acid by termite gut microbes
Symbiotes of termites used to break down cellulose are held in the
Hindgut and are lost when the insect moults
Trophallaxis
Transferring microbes between each other either through mouth to mouth feeding or hind gut secretion
Coprophages
Consuming dung and moves these nutrients back into the soil
Coprophages adaptations
Finding dung and laying eggs
Juveniles can feed on dung to grow
Dung beetle dung use
Roll dung to females to allow for egg laying on top and to basically call dibs on a pile of dung or use it as a sexual display
Dwellers
Adults dig into dung and lay eggs inside
Rollers
Like dung beetles roll the dung and lay eggs
Tunnellers
Adults rip apart dung and burry it for future generations
Larval dung beetles
Has special organs used to breakdown plant material like a cow
Take a long time to develop because diet is not nutritious
Necrophages
Feed on dead organisms
These organisms are very sensitive to dead matter
Carrion beetle adaptations
Release secretions on dead organism, basically marking it and preventing other organisms from eating it
This allows their larvae to eat it instead
Stadium
Amount of time between successive moults
Degree days
The degrees over a temperature threshold that accumulate over a day
Has a lower and upper threshold, falling between the two allows for development
Instar
Stage of development
Voltinism
Number of generations per year
Warmer temps allow for faster development
Bivoltine
Make 2 generations per year
Multivoltine
Make more than 2 generations per year
Forensic entomology
Using insects in the field of criminology
Medicolegal Forensive Entomology
Insects are used to for cuts or other things in identifying homicides
Role of forensic entomologists
Finding timings of certain things in forensics by looking at life cycles of insects in dead bodies
Can also tell if body is moved by the type of insects
Can also tell if someone is poisoned
What affects insect development most
Temperature
Insects can also indicate
The type of changes a dead body has undergone
Postmortem interval
Telling the time of death by determining when arthropods enter a corpse
Forensic entomologists use
Degree days to find the stage of insect development and time of death of the corpse
Degree day models are used
When bodies are still fresh
Step 1
Collect maggots or other first colonizers
Step 2
Identify species to find developmental time of organism to find when the body died
Step 3
Estimate developmental stage
Step 4
Obtain climate data where the body was found
Step 5
Calculate Degree-days to find Post-Mortum-Interval
Step 6
Estimate when eggs were deposited on corpse
Insect succession
Change in species composition in relation to the stage of a corpse
3 main groups of arthropods that colonize a corpse
Necrophages
Predators
Incidental organisms
Time of insect arrival is dependent on
What type of food is available (IE tissue or bones)
Predators
Feed on necrophages and the corpse
Incidental organisms
Use things on the corpse or near it for habitat and shelter
The first stage of decomposition
Fresh
compounds are released from the corpse that attract necrophages
Maybe some flies that deposit eggs on the corpse
These maggots feed on the dead tissue
The second stage of decomposition
Putrefaction
Initial species are joined by other species of flies and beetles as well
The third stage of decomposition
Black putrefaction
Maggots that have developed exit to pupate in the soil nearby
Adult flies leave as corpse is unsuitable for maggot development
Beetles dominate
The fourth stage of decomposition
Butyric fermentation
Butyric acid is produced and there is little flesh at all
No more flies only beetles and some mites
The fifth stage of decomposition
Dry decay
little remains of the corpse other than bones and some dry skin
Most beetles leave and incidental organisms arrive
If insects are drawn away from the mouth
It is the sign of a wound that they are drawn to
Insects can also tell if the body has
Drugs by bioaccumulation of maggots
Bodies that are frozen or buried
Are difficult for necrophages to reach
Forensic entomology can only be used
In warm temps
