Thursday, October 2, 2014

Entomology lab reflection

Alexys Bergeron

                On September 8, 2014, our Forensic class started an entomology experiment. We became young forensic entomologist this day. Our experiment was done right in front of the Blackstone River which is in front of our school. The area was shrubby and filled with grass and random trash. We set up a pork shoulder under a trap and began to observe everything carefully. We came outside a few times to check on the decomposing shoulder and to collect data, such as maggots and its appearance. We got an understanding of what types of insects that were found or got laid on the shoulder and the stages they went through.  This was quite the experience.
Every day that we went outside, there was something different with the pork shoulder.  The day that we started the experiment, flies were already trying to get at it. There were insects such as wasps, blowflies, blue bottle flies, and more. These flies of course began to lay their maggot eggs on the shoulder. On September 10, the meat really began to decompose; the skin was no longer visible. You could see maggots inside some of the wounds of the meat. A few days later, the meat started to turn a dark color, almost black and started to smell absolutely disgusting. On September 17, the meat was basically gone and there was nothing but bone. The insects have eaten the meat and it of course decomposed. During these days we collected maggots and pupas. Some have even turned into adult flies and flown away.
With the data collected, we calculated the PMI and the ADH. The data that I have seems to be almost accurate to the published data, which was pretty good. During these days, we collected the temperature of the meat and it decreased every time. We can get information also by the stages of the insects. These insects have developmental stages which happen as soon as they are laid on a corpse. Depending on the temperature, if it’s cold, the process is slowed, if the temperature is hot, it can speed up.  Our temperatures were at a good point which helped the growths at a good speed. The PMI that was recorded was again very close to being accurate with the published data, which was great.

This experiment really helped us students understand the process of decomposition and the ability to find how long something has been dead using insects. Although forensic entomology might not be used for every crime, it has helped solve many cases. Yes, insects can be pretty gross, but they can help out a lot. Insects are found on every dead body unless things have been messed with.  This experiment was not only fun and crazy but it was very educational and helpful.

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