beetles Flashcards
- whats the common name
- where found
- evidence of
- association w dead bodies
- is this an insect
- taxonomic group
- spider
- on clothing
- terrestrial habitat
- accidental or adventive, not a carrion specialist, hides in clothing or body to hunt other insects
- no
- class arachnida
- whats the common name
- where found
- evidence of
- association w dead bodies
- is this an insect
- taxonomic group
- black blow fly
- on dead bodies
- recent death
- yes, early arriver on large carcasses and is a carrion specialist
- yes is an insect
- Phormia regina, family calliphoridae, order diptera
- whats the common name
- where found
- evidence of
- association w dead bodies
- is this an insect
- taxonomic group
- carpet beetle or museum beetle
- on mummified bodies
- old stage, dried carcass
- yes, carrion specialist and dried protein
- yes an insect
- family: dermestidae, order: colleoptera
- whats the common name
- where found
- evidence of
- association w dead bodies
- is this an insect
- what stage
- bed bug
- houses, on clothing and bedding and car seats
- body was indoors
- accidental, hides in clothing
- yes an insect
- adult
what is the best insect bait
actual bodies, not things that smell like bodies
what was the main discovery of the Trumbo et al 2021 study
traps supplemented w both methyl thiolacetate and dimethyl trisulfide attracted greater numbers of beetles
true/false insects can strip a carcass rapidly
true
true/false colonizing a carcass is distinct
- false
- it is not distinct
- waves of colonization overlap
- geographic and seasonal differences exist
what did megnin 1894 identify about insect colonization, and what has changed
- identified 8 invasian waves on human corpses
- ecologists group these stages together into as few as 2 stages
- this has ecological utility but not useful for forensic entomologists
what did payne 1965 identify
- used pig carcasses to identify 6 stages of decay
- fresh, bloat, active, advances, dry, remains
what did bornmissza 1957 identify
- found 5 stages of decay
- initial, putrefaction, black putrefaction, butyric fermentation, dry decay
what is the timeline for bornmissza’s 5 stages of decay
- initial (0-2 days), appears fresh, decomposing internally due to bacteria found on body prior to death
- putrefaction (2-12 days), swollen by gas produced internally, odour of decay
- black putrefaction (12-20 days) fresh creamy consistency, exposed parts black, body collapses after gases escape, strong odour
- butyric fermentation (20-40 days) carcass dries out, some flesh cheesy odour, top mouldy from fermentation
- dry decay (40-50 days) almost dry, slow decay
are there differences when the carcass is in the shade or sun
- yeah
- the temp changes, and so does decay speed
true/false phaenicia has replaced some lucilia
- false
- Hall 1948 proposed to change the genus name for some but instead they just left it all as lucilia
roughly which stage of decomp are blowfly larvae there for
- putrefaction
- black putrefaction
roughly which stage of decomp are staphylinidae there for
- black putrefaction
- butyric fermentation
roughly which stage of decomp are histeridae there for
- putrefaction
- black putrefaction
- butyric fermentation
roughly which stage of decomp are dermestes there for
- black putrefaction
- butyric fermentation
roughly which stage of decomp are dermestes larvae there for
- butyric fermentation
- dry decay
roughly which stage of decomp are collembola there for
- all of them
- slightly more at putrefaction but still all
roughly which stage of decomp are gryllidae there for
putrefaction
roughly which stage of decomp are dermaptera there for
all of them
roughly which stage of decomp are psocoptera there for
putrefaction
roughly which stage of decomp are coleoptera there for
- putrefaction
-
then theyre gone, then back for
-butyric fermentation - dry decay
roughly which stage of decomp are pseudoscorpiones there for
- all of them
- more at start and end but still all
roughly which stage of decomp are acari there for
- all of them
- more at start and end but still all
what are ants and earwigs useful early on vs later stages
- early PMI
- better indictors of location in later stages
____ and _____ differences exist in colonization
- geographical
- seasonal
roughly which stage of decomp are blow flies there for
- fresh
- bloated
- decay
roughly which stage of decomp are ants there for
- bloated
- decay
- (a little fresh and dry but not really)
roughly which stage of decomp are rove beetles there for
- bloated
- decay
roughly which stage of decomp are cheese skipeprs there for
- bloated
- decay
roughly which stage of decomp are checkered beetles there for
- decay
- dry
roughly which stage of decomp are dermestid beetles there for
- decay
- dry
roughly which stage of decomp are hide beetles there for
- decay
- dry
what family are beetles
silphidae
what do adult beetles feed on
- decaying material
- carrion
- prey on fly larvae and snails
what do larvae feed on
carrion
how do adults find carcasses
- via ocour cues (olfaction) sensilla on terminal antennal segments
- they detect hydrogen sulfide and cyclic carbon compounds
true/false some adult beetles carry nematodes and cestodes, which infect humans and dometic animals
- False
- they do carry nematode and cestodes
- these do not infect humans or domestic animals
what do beetles compete with for carrion
flies
describe the study of rabies and anthrax and beetles
rabies were deactivated in gut of Nicrophorus but anthrax bacilli may be spread
what four families of mites do beetles carry
- Parasitidae (this is the most common)
- Anoetidae
- uropodidae
- macrochelidae
what are the 2 subfamilies of Silphidae
- nicrophorinae
- silphinae
describe the structure of nicrophorinae
- elytra shorter than abdomen, usually exposing 3-4 abdominal tergites
- elytra usually w red or orange markings
- second anetenal segment small hidden in tip of 1st segment
describe the structure of silphinae
- elytra covers abdomen, or exposes 1-2 tergites
- second antennal segment not hidden, large
how can we tell family vs subfamily between silphidae and silphinae
- silphidae is family cause dae
- silphinae is subfamily cause nae
what are the 4 necrophorines
- nicrophorus sayi
- nicrophorus orbicollis
- nicrophorus tomentosus
- nicrophorus pustulata
- nicrophorus sayi
- look at the red markings and 3 abdominal tergites
- yellow antenna tips
- antennas go sideways not forwards
- nicrophorus orbicollis
- look at the red markings and 3-4 abdominal tergites
- yellow eyes and antenna bits
- antennas go forwards not to the sides
- nicrophorus tomentosus
- look at the red markings and 3-4 abdominal tergites
- yellow thorax (the bubblebee guy)
- also buzzes like a bee
- nicrophorus pustulata
- 3-4 abdominal tergites
- no red marks
- all black and the tiny bit of brown
what are the four silphines
- necrodes surinamensis
- oxelytrum discicolle
- oxelytrum inaequale
- necrophila americana
- necrodes surinamensis
- 2 abdominal tergites
- fully brown
- little lighter brown line around bottom
- oxelytrum discicolle
- no abdominal tergites
- yellow/ orange thorax
- legs go parallel to body
- oxelytrum inaequale
- 2 abdominal tergites
- grey body and tiny head
- necrophila americana
- 2 abdominal tergites
- light yellow thorax
- little yellow line along bottom of abdomin
describe the life history/ timeline of silphinae
- breed at large carcasses, adults find dead body, then mate
- females oviposit on soil around carcass
- 2-7 days, larvae hatch, then move to carcass to feed
- 3 larval instars
- pupate in soil 14-21 days
- wait for fly maggots to finish feeding to avoid competition: sooo beetle eggs hatch when 1st gen flies are leaving to pupate
- little to no parental care
describe the life history of nicrophorinae
- breed at small carcasses
- adults will find animal (mouse/vole) and crawl over it to assess for suitability for burial
- they burrow into soil under carcass, and push soil out from sides so body sinks into ground
- beetles create crypt with carcass in centre
- 1 pair of beetles per carcass, will fight if more than 1 pair
- pair strips carcass of hair and rolls into ball
- female digs utnnel and lays eggs
- males leave chamber
- larvae hatch, move to food, and female chews hole into carcass to allow larvae entry
- larvae enter the hole and mother feeds larvae for about 6 hours, then they feed on their own
- 3 larval instars
- pupate in soil
- female leave chamber
what makes the genus nicrophorus unusual among beetles
they have biparental care young
what is the timeline of the larvae and pupae for nicrophorinae
- tunnel is dug and eggs are laid within 48 hours
- once eggs hatch, mother feeds for 6 hours
- 1st instar is 12 hours
- 2nd is 24 hours
- 3rd is 5-15 days
- pupate for 13-15 days
what is the timeline for silphinae
- larvae hatch after 2-7 days
- 1st instar 3-7 days
- 2nd is 3-10 days
- 3rd is 3-10 days
- pupate in soil for 14-21 days
what weird defensive behaviour do silphids have
- will raise their abdomen in imitation of a stinger, creating a rasping sound like a bee or wasp
- they then produce and squirt a foul smelling liquid for anus, probably toxic
- colouration is likely warning, so birds avoid them
give some info on necrodes surinamensis
- large carcasses
- attracted to light
give some info on necrophila americana
- late spring early summer
- diurnal (are out and about during day)
give some info on oiceptoma inaequale
- early spring
- one generation per year
- diurnal
- fringe of hair at eyes
give some info on oiceptoma novaboracense
- early spring
- one generation
- forested habitats
give some info on thanatophilus lapponicus
- early spring
- dominant species, often the only one collected
- northern species
- can be found around garbage piles or burning barrels