entomology- lqc 1b Flashcards
entomology definition
the study of insects and their life cycles
what does a forensic entomologist need to collect once a body has been found
samples of each insect, noting where each was found. the air, body and ground temp. the ‘maggot mass’. information about the habitat. the condition of the body and temperature/weather history of the location needs recording
how are collected maggots used?
length of maggot is measured to determine age. live maggots are fed in meat and allowed to complete their development to adult to aid species identification and the timing of their pupation
describe the process to determine the time of death
maggot length can be compared to growth graph to establish their age. the stage of maggot development can be linked in with the fly life cycle timings. this information helps work back to when the egg was laid. this is only reliable if the ambient temp has remained constant
why is the time of death considered to be an understatement when using entomology
there is no way of knowing when the fly found the body so the time is the minimum estimate
state the factors that can affect the estimation of the time of death
temperature affects rate of progress through life cycle and growth. toxins in the body could speed up (cocaine) or slow down (heroin) maggot and pupal development
state the factors that can determine which insects are on the body at a particular time
the stage of decomposition of the body ie has phase or drying phase. the presence of other insects (predators would be attracted)
why is the colonisation of insects on a decomposing body considered to be a form of succession
One group of organisms feed on the body, changing the conditions (biotic & abiotic) so that they become attractive to another group – species are replaced by others over a period of time. But, the first species may still be present. The species richness increases.
what other information can insects provide
If the body has been moved to another location – species will be different in different habitats
in conclusion, why is forensic entomology so useful
There is a predictable sequence of organisms that feed on a decomposing body. There is detailed knowledge about the life cycle timings for each species.
