Forensic Science Chapter 11 Test

what is 1 reason why insect evidence at crime scenes is often not collected

investigators are often not properly trained to find and collect insects

why is it necessary to collect larvae from around a body not just on the body

it's necessary because you need to collect larvae from around the body to see what insects are common in that area and compare that to the larvae on the body to see if there the same types of insects if not the body was moved

what is the significance of sending live larvae to a forensic lab?

live larvae are significant because the scientists can see what they eat

if live adult beetles are collected using a net, why is it important to place them in individual jars when shipping them to a forensic entomologist

so that way the beetles don't contaminate each other

adult flies are attracted to dead bodies because of their odors

true

which is the correct sequence of developmental stages for blowflies

egg, larva, pupa, adult

a well- trained forensic entomologist can always determine PMI using insect evidence only

false because they also need other factors such as environmental conditions

for each of the following describe how insects can be useful in solving a crime: a. indicating where a body is hidden b. determining the primary scene c. determining that the body was buried shortly after death d. Determining if the deceased was under the influence of drugs

a: the presence of flies, their eggs or larvae, or other insects all help reveal a body or remains b. insects identify a geographic range and certain insects can only live in certain areas which helps to specify whether it was in the desert, woods, etc c. if the body was buried shortly after death, then the colonization of insects would be slightly delayed d. insects who were feeding on parts of the flesh that affect the body where the drugs were will make the insects grow faster and the larvae may have human tissue stored in their crops that can be analyzed for drugs

what value is there in collecting empty pupal cases from a crime scene where no live insects are evident

an empty pupal case can provide evidence that a body has been in an area long enough for the blowfly to complete its full life cycle

which represents the normal sequence of decomposition

fresh ,bloated, active decay, advanced decay, dry decay

at crime scenes, investigators need to record information about the habitat and the environmental conditions. relate the importance of habitat and environmental conditions to the forensic entomologist's interpretation of the insect evidence

habitat and environmental conditions are important because insects can only live in certain areas and depending on the temperature, sunlight, etc... along with the insect evidence can help estimate a PMI

compare the anterior end of the blowfly and the posterior end of a blowfly

the anterior end is how the blowfly eats and the posterior end is how it breathes

compare the preferred food source for blowfly larvae and the preferred food source for carrion beetle larvae

the blowfly larvae feed on decomposing flesh and beetle larvae will eat different parts of the flesh depending on what they need

compare and contrast the second instar and the third instar of the blowfly

the second instar first appears in 2.5 days, is 10mm and lasts 15-20 hours. the third instar first appears in 4-5 days, is 17mm and lasts 36-56 hours

which is true regarding spiracle slits of blowfly larva

they are useful in estimating the age of a blowfly larva

insect evidence is the most accurate method to estimate a postmortem interval if the victim is dead less than 24 hours

true

wasps arrive after the blowflies because they feed on blowfly larvae and eggs

true

when estimating a postmortem interval, it's important to factor into the interval the fact that flies and beetles don't lay eggs at night

true

if there are various stages of larvae on the corpse, why should you collect the largest samples

when they're larger it helps figure out the ADH