intro Flashcards
true/false a corpse is not a highly nutritional package
- false
- it is a highly nutritional package
what is the goal for immature insects
to obtain lots of food quickly
what is the goal for adult insects
- find mates
- disperse and find new carcasses
true/false the major problem for insects is the availability of food is unpredictable
- true
- theyre either in feast or famine
maggot growth has what kind of distribution
normal distribution (some come early, others come a bit later)
what are intrinsic factors of variability
early, optimal, late colonizers, distance to other nearest corpse, number of colonizers available, intraspecific competition
what are extrinsic factors
- moisture, sun/shade, species that arrive, distance to nearest corpse, rarity of corpses, predators, diseases
- variability associated w the carcass (size, any drugs they took. how much fat/meat)
true/false maggts prefer muscle over brain
- false
- brain is lots of fat, which they like
describe the structure of insect cuticle
- polysacharide called chitin
- layers of chitin stacked to create strong, flexible structural membrane
what are forensically relevant insects used for in cases
identifying a time and place
what is the most common use of insects in forensics
finding PMI estimations in victims of homicides
true/false immature flies are called larvae
- false
- they are maggots
- can be called fly larvae but not larvae on their own
what are some things that show changes in PMI
- weather
- time eggs are layed
- when insects hatch
- when insects arrive
name some sources of variability thata re associated with the carcass
- size of corpse
- presence of drugs or food
- health of individuals
- fat vs lean meat
- access to carcass
- exposure to internal organs
what is the hard material of the exocuticle made of
a protein called sclerotin
true/false the layering of insect cuticle allows us to age it by counting the cuticular band
- true
- kinda like counting tree rings
- at apodeme between the thorax and abdomen
insects are externally coated with what
wax (cuticular hydrocarbon)
what do insects use to breathe
- spiracles
- or holes connected to tracheal tubes that extend throuhout the body cavity
what is the power of insect muscles proportional to
the power is proportional to cross section area
what are muscles attached to
the outside structures
what can be used to dissolve the muscles of insects
10% conc KOH
where are eggs deposited
- various locations
- generally in folds near cavities and openings
how many instars are there in maggot development
3 instars
true/false maggots are always smooth
- false
- maggots can be hairy, covered in setae, or smooth
what is sued to identify the different instars
the mouthparts and spiracle aptterns
maggots wander from the corpse and turn into what
pupae
describe the life cycle of flies
- Flies lay eggs
- Eggs become active and get nutrition (larvae or maggot stage)
- Go back to an egg-like stage (pupae)
- Then become adult flies
The specialized structures of maggots are based on what
habitat
true/false pupae get lighter with age
- false
- they get darker
what is the basic structure of adult flies
- head
- thorax
- 2 wings and halters
- beetles
- hard front wing
where is the sagital plane
where is the transverse plane
where are the anterior/posterior ends
what part of the body is this and why do we care
- this is the thorax
- the location of the presence of the hairs can be used to identify the species
where is the head
where is the thorax
where is the abdomen
what is this
the side view of the thora
