Lecture 1

Question 1

What is the major problem for bugs?

Answer 1

there is a little food in the wild and there is either a famine or feast

Question 2

For forensic use we can use insects to identify:

Answer 2

where and when events occur

Question 3

what is the theoretical timeline of a carcass?

Answer 3

death -> stages of putrefaction -> stages of mummification

Question 4

what is the theoretical timeline of a fly?

Answer 4

flies colonize -> growth of larvae -> pupae -> adults emerge

Question 5

why is the timelines of both carcasses and flies very variable?

Answer 5

because some lay eggs early and some arrive a bit later, variability increases as the carcass ages

Question 6

Why is growth of flies slow in low temps and fast in high temps?

Answer 6

because they are ectotherms

Question 7

what are intrinsic factors?

Answer 7

• early
• optimal
• late colonizers
• distance to other nearest corpse
• number of colonizers available
• intraspecific competition from other colonizers

Question 8

what are extrinsic factors?

Answer 8

• moisture
• sun vs. shade
• species that arrive
• distance to nearest corpse
• commonness or rarity of other corpses, predators, parasites and diseases

Question 9

Where does variability mainly occur?

Answer 9

• size of corpse
• presence of drugs
• food
• health of individual
• amount of fat vs lean meat
• order of organs colonized
• order of utilization
• exposure of interior organs and body cavities
• access to carcass

Question 10

What is the most common colonizer?

Answer 10

blow flies that deposit eggs

Question 11

What happens if a burying beetle finds a fresh corpse?

Answer 11

they will ingest it before the flies arrive

Question 12

what is the real name for burying beetles? what is the family?

Answer 12

sextant beetle, Silphidae

Question 13

what happens if burying beetles carry mites?

Answer 13

the mites will eat the fly eggs and first instar larvae, also mites will eat the beetle eggs

Question 14

what is the latin name for mites?

Answer 14

Machrocheles muscaedomesticae

Question 15

What is a good example of variability, sunlight and shade?

Answer 15

WW1 trenches

Question 16

In trenches what was on the sunny portions?

Answer 16

blue bottle flies (Calliphora vicina)

Question 17

In the trenches what was on the shaded portion?

Answer 17

Green bottle flies (Lucillia)

Question 18

What makes up an insect cuticle?

Answer 18

polysaccharide called chitin

Question 19

how is chitin structured?

Answer 19

layers are stacked creating a strong structural membrane

Question 20

T/F: chitin is flexible

Answer 20

True

Question 21

what makes the exocuticle hard?

Answer 21

sclerotin

Question 22

how can you count the age of a insect?

Answer 22

Like a tree count the layers of the cuticular bands

Question 23

what is the entire external surface of an insect coated in?

Answer 23

wax (cuticular hydrocarbon)

Question 24

where do insects breath through?

Answer 24

spiracles

Question 25

where are the most muscles concentrated in insects?

Answer 25

wings

Question 26

insects have a better ___ system than mammals

Answer 26

leveraging; they are attached to the outside structures that allow leveraging to be applied

Question 27

what can insect muscle be dissolved in?

Answer 27

KOH at ~10% concentration

Question 28

what does holometabolous mean?

Answer 28

eggs to larva to pupa to adult

Question 29

where are eggs generally deposited?

Answer 29

in folds near cavities and openings

Question 30

T/F: flesh flies lay eggs

Answer 30

False

Question 31

how can you determine the three different instars?

Answer 31

they have three spiracles for third, two for second, and one for first

Question 32

Are maggots always smooth?

Answer 32

no some can be hairy and covered in setae

Question 33

how can you tell the age of a pupa?

Answer 33

darker it is the older it is