FS 318 Ch 7 (4)

Other insect collection

All insects (flies, beetles) should be collected and preserved in alcohol individually (can store individual species together) -Ants/wasps are predators of eggs -Beetles must be stored individually (will eat smaller beetles and flies)

Pupae

Blowfly evidence specimen collection Collect + place in vial w/ paper towel to cushion them (do NOT preserve) -Buried in dirt several centimeters deep + scattered sever meters away from body (3-5 ft) -Empty pupal cases are collected + kept alive

Maggot masses

Blowfly evidence specimen collection -Take temp of ____ ____ -Sample collected + stored separately from each other (include large + small maggots from each mass) -Place in alcohol mixture or hot water -Sample of live maggots in vial (don't overcrowd + include food source- beef liver) -Check area for pre-pupal 3rd instar larvae (package them separately- they're getting ready to move off found source + won't survive well w/ 1st + 2nd install

Exclusion of insects

Challenge -Body may have been frozen after death -If this occurred naturally, during winter, insects will colonize remains when they thaw in spring -If artificially frozen in freezer, insects will be excluded until remains are removed from freezer + allowed to defrost -Insects could colonize remains + time since thawing can be determined

Burial or wrapping

Challenge (Exclusion of insects) Burial affects colonization, but few homicide victims are buried deeply enough to exclude all insects Wrapping body can limit/delay insect activity, but rarely completely impedes insects -Cases of bodies being wrapped in plastic/other materials or locked inside boxes, bags, or cases have been documented in which insects were able to colonize body

Season

Challenge (important) -Insects are seasonal Entomology is of value only in spring, summer, and fall in temperate climates -When remains are found in winter, not much can be done -In some cases, presence of cold season may be of value in setting boundaries (if remains are found in winter + indicate presence of insect activity, death must've occurred prior to onset of cold season) Equally valuable all year long (sub)tropical regions -Entomologists understand how different species function in different season -Just because it's winter doesn't mean you won't find insects

Temp

Challenge (most important) -Impacts insect development -Actual temp of scene + temp insects were exposed to is unknown + estimated -Temp can be estimated + extrapolated from weather station w/ data loggers placed at scene -Macro + micro climatic factors must be taken into account -Use of data logger at crime scene indicates if data collected at weather station is valid for crime scene + if scene is warmer/cooler than that recorded at weather station -Statistical analysis allows entomologist to deduce scene temps based on comparison of temp data at scene + weather station Microclimates -Ex: Amherst gets dusting of snow but Hilbert gets feet of it -In same region, but because of close proximity of lake by Hilbert, they tend to get lake effect snow that doesn't reach amherst -Use NOAA.gov

Blowfly evidence

Collected at all stages of development Eggs: Collect clump size of dime -Preserve 1/2 of sample in alcohol mixture -Other 1/2 kept alive + placed in vial w/ beef liver (if maggots hatch, they'll eat each other) -Eggs must be regularly observed to determine time of hatch (when everything is submitted to entomologist) -Number of eggs hatched + when first hatch occurred should be recorded + continue through life cycle to see what insects they are (maggots look similar)

Entomological evidence

Collection of ____ ____ -____ ____ should be collected at crime scene -Remains of buts or pupal casings and body + environment should be observed + photographed before collection of insect stages begin -Thermometer placed on maggot masses to measure temp -Maggot masses generate heat -Depending on how much heat, entomologist has standards to compare it to to see how long mass has been there

Adult blowflies

Have little forensic value unless they're still wet + emerging from pupae -Collected + labeled as undeveloped fly -Collect a few of them to see what type of maggots may be present

Other information

____ ____ required Soil sample from close to body: -Not too close where purge fluid is -pH + nutrient base affects how pupal phases go Weather conditions: -Could find frozen fly eggs that thaw out (maggots can survive) -Use NOAA.gov Collection at morgue: -Same manner as when in field (some kept alive, some preserved) -Send them off for testing -Use maggots for human DNA + drugs person ingested

Challenges

____ to forensic entomology -Temp -Season -Exclusion of certain insects based on when body was deposited at location + above named factors -Burial/wrapping effect impact of colonization