Lecture 16 - Insect recyclers & forensics

environment without insects would..

collapse

ecosystem

all living & nonliving components of the environment

decomposers

process dead & decaying organic matter

importance of decomposers

removes dead plants & animals, convert organic matter into simpler substances, CNPHO recycled with the four main cycles on Earth

soil

dwelling insects, Beetles

biomass

renewable organic material from plants and animals

energy flows...

up through trophic levels in the form of biomass

can energy flow in other ways

no, one-way

outside supply of E is

sun

carbon cycle

exchange of carbon through the atmosphere

sinks

areas where carbon is mostly absorbed than released (forests, oceans, soil

sources

release more than absorb (fossil fuels, deforestation, respiration)

fluxes

movement of CO2 (ocean-atmosphere exchange)

necrophageous insects

flies (blow flies, flesh flies), beetles (burying beetles, skin beetles)

traits of necrophageous insects

sensitive to odors of decay & putrefaction, some digest collagen & keratin, grow rapidly, pupate over wide range of sizes & time

species colonize in...

progressive, predictable way (why it is useful for forensic entomology

what affects forensic findings?

time of day, exposure to elements, geographical location, manner of death, poison/drugs

these insects can be helpful

maggots for maggot therapy, cleans and heals wounds

predictable changes in body after death, immediately...

release of body fluids & gases, bluebottle flies & house flies

soon after death, fermentation

flesh flies & wasps

fats break down

volatile fatty acids released, hide beetles & others

proteins breakdown

cheese skippers

body fluids evaporate

silphid & hister beetles

desiccation

collagen digesters, skin beetles, clothes moths