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
