Lecture 3 Flashcards
T/F: Spiders are insects
FALSE
What is a bug in the class arachnida that eats other bug eggs?
mites
how do mites disperse their eggs?
phoresy: carried by other insects
what are the mites that are commonly found in compost?
Cunaxidae
what do mites alter?
alter or delaying successional patterns of decay
what do macrochelids indicate on a body?
possible origins of a corpse
where are macrochelids usually found?
agricultural regions
what is the problem with collecting mites?
difficult to collect and see
what is the structural parts of a spider?
8 legs, 2 body parts: abdomen, and cephalothorax
what are the body parts of pseudoscorpions?
they have 2 body parts: abdomen and cephalothorax
what is the most distinguished parts of pseudoscorpions?
pedipalps (pinchers), and mouthparts
how do psuedoscorpions disperse?
via phoresy: attached to flies
What bug is associated with decomposing remains and found at all stages?
pill bugs
How many species of malacostraca are there in Ontario, are they native?
13 and mostly no
What class are centipedes
chilopoda
what insect is predatory on other arthropods (clue: both found indoors and outdoors)?
centipedes
What class are millipedes?
diplopoda
where do millipedes live?
moist habitats, plant feeders but also on decomposing animal tissues
how many species of millipedes are there in Canada and Alaska?
60
What insect is order collembola?
springtails
what is another name for springtails
snow fleas
What is the class name of silverfish?
Thysanura
where is the typical location of silverfish?
households generally inside pest of stored food products
what are the worst insects for killing people?
houseflies and mosquitos
What do cockroaches do to carcasses?
feed on them
when do cockroaches appear?
commonly at later stage remains, not fresh corpses
what order are cockroaches?
Blattaria
where are earwigs found?
damp habitats, and commonly beneath a corpse as daylight shelter area
what order are earwigs?
Dermaptera
What is the most abundant order?
Coleoptera
when are beetles found?
early stages of decomposition
What is the main predatory beetle?
Staphilinidae
When do predatory beetles arrive?
early after death and remain through the rotting cycle.
what is the class of ground beetles?
Carabidae
what are histerid beetles?
shiny black and robust beetles
what do histerid beetles do?
Feed on maggots, stay throughout decomposition period.
What is the common name for silphidae?
burying beetles
what do silphidae larvae feed on?
this is a tricky question, some authors say remains and maggots others say only on maggots
What is the common name of dermestidae?
carpet/museum beetles
what do dermestids eat?
dry skin, hair, larvae, and adults
how are dermestids forensically relavent?
not necessarily the corpse but rather identifying location
when you get a reaction from dermestids on your skin what should you do?
olive oil on skin
what order are caddisflies?
trichoptera
Why are caddisflies Dave’s favourite insect?
because they make pretty shells made of sand twigs and leaves
where do you normally find caddisflies?
submerged corpses, and often in clothing
what were red bloodworms (chironamidae) misidentified as?
carpet fibres
what is the proper name of mayflies?
ephemeroptera
what is the order of flies?
Diptera
what is the anatomical wing structure of flies?
two wings, hind wings are reduced to halterese
T/F: Flies have 4 wings.
false
which type of fly arrives first in cooler climates?
calliphoridae (blow flies)
which flies arrive first in warmer temperatures?
sarcophagidae (flesh flies)
how can you distinguish flesh flies?
checkered abdomen
where do blow flies deposit their eggs?
folds, eyes, ears
T/F: blow fly maggots are predatory on other maggots.
True
3rd Instar Maggots release enzymes to do what?
liquify tissue
what is the family name for cheese skippers?
piophilidae
where are cheese typically found?
- stored products and dried foodstuffs
- slaughter houses and tanneries
T/F: maggots can jump.
True: they can jump up to 3 in to escape from predators
Cheese skipppers can tolerate temps of __ for 1 hour and __ for 24 hours
54 and 45
when do cheese skippers appear on a dried corpse?
later
what is the least amount of time adult cheese skippers have been found?
as soon as 3 days on small carcasses
What did Johnston and Villenueve find in 1897?
found cheese skipper larvae on corpse after saponification (turning fat into soap) had occured
What is found in 10% of graves 3-10 yrs old?
cheese skipper maggots
What insects are simple and ametabolous? what does that mean?
silverfish, & collebola immature look like adults
what insects are incomplete or hemimetabolous, what does that mean?
earwigs; larvae similar to adults but missing key structures (wings)
what insects are complete or holometabolous, what does that mean?
maggots, grubs; means they go through several distinct stages or through moults or instars
What instar of maggots have keys?
all but mostly for 3rd, some for 2nd, and very few for 1st
Where and how do maggots emerge from?
the plastron, they split it at the length
How do adult flies emerge?
- breaking open pupae with a specialized temporary structure called a ptilinum
- head sweals to break pupae
- fly emerges and the ptilinum shrinks, fly exoskeleton hardens
What does damage to the exoskeleton of a fly do?
leaves a scar
Why does rigor mortis occur?
breakdown of glycogen and accumulation of lactic acid
when does rigor mortis start/end?
begins: 5-7 hrs
lasts: 48-72 hrs
what is rigor mortis mitigated and lengthened by?
high temperatures and lengthened by low temperatures
What occurs after rigor mortis?
biochemical fermentation and autolysis
what gases are released during fermentation?
ammonia, hydrogen sulfide, carbon dioxide, and nitrogen
during the bloat stage what happens?
flanks become greenish and carcass bloats
why does putrefaction occur?
micro organisms in the body (intestinal flora) followed by invading saprophytic fungi and bacteria
when do necrophagous insects appear?
after autolysis
What do larvae feed on in a carcass?
liquid between muscle fibres
what is the order of body decomposition
- Intestines, stomach, liver blood, heart blood, and circulation heart muscles
- lungs, air passages
- brain
- kidneys and bladder
- voluntary muscles
- uterus
how long is liver unattractive for?
3 hours after removal
