Forensic Entomology Lab Report

Zachary Hamel

Advanced Forensics

Entomology Lab

10/2/14

          

           Our advanced forensics class established and created a lab to aid us in our study of decomposition and forensic entomology and the effect insects have on decomposition. On September 8^th, our class went into the front of Tolman in from of the Blackstone and dug a well sized hole. Next, we unwrapped the pork shoulder and placed it inside the hole, not too deep. We then placed a cage like covering over the pig shoulder, and used spikes rocks and some zip ties to make sure no outside variables or animals would come into contact with our pork shoulder and affect our decomposition and data. As soon as the pork shoulder was placed on the ground and left long enough without any disturbance, flies were migrating towards the body within minutes, and beginning to lay their eggs.

In the first couple of days that would pass, we had a minor heatwave, which could have possibly affected our rate of decomposition. We went outside to check on the shoulder each day, and saw little to no changes in appearance, or any insect activity. It wasn't until we went outside on September 10^th or around there, that we saw a notable difference. It was on this day that we could finally examine and analyze the notable insect activity on, in, and around the pork shoulder. There were now bees picking apart at the flesh and tissues, flies were still swarming around the crevices and open areas of the pork shoulder, and maggots had become present in and around the shoulder. They were eating away at the flesh little by little. It was also at this time, that the skin began to get very hard and stiff, and change color from a beige almost pink, to a green almost turning brown. We later went out around the 16^th or 17^th of the month to examine the shoulder again, and it was during this observation and analysis that we could see the maggots swarming all over and around the body seriously eating away at it, making the body decompose very progressively. The skin and shoulder at this time, or what was left of it, had turned a very dark brown almost blackish color, and the smell of it was almost unbearable, so much that Vick’s had to be applied to come within observing distance. The maggots had begun the third instar, or the third form a larvae before they begin to pupate.

At this time, it was time for our class to finish our observations of the pork shoulder and begin to collect, mark down, and analyze our data. What we were trying to do was analyze the information we took from the pork shoulder and the given insects around and on it, to find the PMI or post mortem interval, to try and see how forensic entomologists do these same tests to conclude when a body has died or been killed. We gathered data from the national weather information on average temperatures from each of the days we went outside and made our observations. The weather during this time could have played a major role in the case, as if it would have been hotter, the decomposition would have been thoroughly sped up, where as if it had been much colder the decomposition process would have been extremely slowed down. Comparing our data with the published data, our results were consistent with the published data, as the average temperatures for the time our pork shoulder was outside was pretty well matched up with the data we got from our analysis.

Forensic Entomology is a great tool and resource to have at your ability, as it can be highly beneficial to solving a crime and finding out the exact day that a body or in this case a pork shoulder, was dispersed of, and began to decompose.  It helps entomologists, and us students, understand the connection that flies, maggots, and all bugs have to a case and how valuable and critical they are in a case, where no evidence is left behind and there are no clues or answers. This lab also helped us to comprehend and understand what the life cycle of a maggot is like and how its different stages of life can all be useful and beneficial to a forensic case. In all, this lab truly showed us how valuable a small little insect like a fly or maggot can be to forensic entomology and to calculating the time of death. 

Lab Reflection

                   I thought I've seen very disturbing things before, but nothing quite compared to a decomposing pork shoulder. In my advanced forensics class we  had the ability set up a lab to research several variables. These variables consisted of the decomposition and forensic entomology.

                  September 8th, we explored the land in front of Tolman near the Blackstone River. Once finding a reasonable place, we began our lab. Materials used were a pig shoulder, a cage, rocks, and stakes,and lastly some zip ties. We had first began to dug a hole to place the fresh pork shoulder in. The next step consisted of placing the cage over it and placing the stakes around the cage. We also surrounded the cage with rocks to help protect it from animals. The zip ties also played a factor in holding the cage in place because we zip tied the stakes to the cage. Almost immediately placing the cage, flies were already starting to swarm the shoulder.

                   A couple of days had passed when we noticed that you couldn't tell much of anything was happening. The next recorded date was September 10th, on this day, you can see that some insect business was occurring. We had injected slits into the pork shoulder with prior knowledge that flies lay eggs in open wounds or orifices. The insects that inhabitant these wounds were flies and  wasps. The next change we saw was the 15th where bone was beginning to show and the skin appeared to be tough and leathery. The same situation was recorded for the next couple of days.

                     The data we have collected over weeks was finally going to become organized and clear to read as we found out the PMI. PMI (Postmortem Interval) means the time of death. To find the PMI we must complete ADH. With the internet access we were able to get the average temperature for the time the pork shoulder was out there. Temperature is extremely important for forensic entomologists because if the weather is warmer, the body decomposes faster, rather than slower in colder extremes. 

                  The purpose of this lab was to give us the understanding of the use of insects in forensic entomology. The lab had moments that were very intriguing while others were disturbing or foul-smelling. The lab was a hands on experience and also helped us to apply our own knowledge calculating the ADH and finding out what types of bugs were laying their eggs in the pork shoulder.

Jared Paquin Forensics entomology reflection

Period 3 of the advanced forensics class set up a lab to study decomposition and entomology. We started to set up around September 8th, we used a pig shoulder, a cage, rocks, and steaks,and lastly some zip ties. We put the freshly unwrapped pig shoulder into the cage to prevent any animal interfering. As soon as the pork shoulder was in the cage some flies were already coming to it.

During the past few days after that you couldn't tell anything was happening. However, on September 10 you could start to see some of the bug activity really take control of this shoulder. The wounds we had inflicted on the pork shoulder housed wasps and flies. The wasps were eating at the tissue, and maggots were starting to emerge out of eggs hungry for the flesh of this shoulder. The skin was tough and leathery and maggot masses were appearing inside the wounds as well as inside the pork. On or around September 17th is where you could see the damage being done. The maggots were in 3rd instar and were in masses deep inside the carcase. The meat was a black green color and the smell was horrific. There was a slimy foam from where the maggots release enzymes to break down the pork so they can eat it.

Now since we had all of our observations done it was time to collect our data or put it all on one table. We were determining PMI (Postmortem Interval) we took the data we gathered and used the weather channel to get the most accurate weather forecast we could for the weeks the shoulder had been there. The temperature can greatly affect the development of the fly larvae. If the temperature is hot the process of instars and pupation to an adult fly is accelerated. While in the cold the process is slowed down. The results  that have concluded the lab from my findings are consistent with what was actually supposed to happen.

This lab has beneficial to the students and the studying of entomology because it gave us a hands on look about the predictable bottlefly life cycle. Also helps us with recording observations and taking data from a situation. To close, the lab gave us a hands on look on what entomology is like and what we have to do to calculate PMI.

Entomology lab reflection by Brian Rego

We started our lab in the beginning of September. On the first day September 8^th we set up a pork shoulder under a protective barrier made out of rocks and a cage type thing for protection from animals. The point of the lab was to observe the decomposition of the pork shoulder and to learn more about forensic entomology through recording and collecting insects that where at the pork shoulder.

On the same day that we first put the pork shoulder down flies immediately found it.  On this day it just looked like a normal pork shoulder and it didn’t smell at all.  On September 10^th the second day that we went to see it the shoulder seemed to be drier, a darker red color and more leathery looking. On this day there were two different types of flies and wasps present at the shoulder. The next day that we went to go see it was the 12^th. On the 12^th the pork shoulder looked a lot drier and it looked like it shrunk a little. The insects present that day were still flies and a lot of maggots.  On September 15^th we could smell the shoulder before we saw it. We could see blackish holes in it and could tell that it was decaying. On this day the insects that were there were flies and maggots. The last day of our lab was September 17^th. On this day it looked and smelt the same as on the 15^th, and the insects at the scene were the same. The only difference was the inside of the pork shoulder had a slimy looking substance created by the maggots.

We used the data we collected at the scene to help determine the Postmortem interval of the pork shoulder.  To find out the PMI we collected maggot samples and we also got the temperature data each day. With this we could figure out what kind of maggot it was and can determine the PMI by using data on that fly to see how long it takes that fly to get to that stage of development under the temperature conditions that we had.  Our data was very similar to the published data.

Forensic Entomology is a very important tool to solving crimes.  The use of forensic entomology makes cases easier to solve and are even the direct cause to solving some cases.  Forensic Entomology is used to figure out the PMI which is the time that has passed since someone has died.  If investigators know the time of death it could help them in their search for the suspect and also cross off some suspects who had alibis. This is why forensic entomology is so important. 

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.

Entomology Lab Reflection: Leiandra Wilson

Leiandra Wilson

                In Advanced Forensics my classmates and I became forensic entomologists. On September 8, 2014 we started our process. Our goal was to see entomology up close and personal and learn more about how it is used in forensics. We took a pork shoulder and put it outside of Tolman near the Blackstone River; it was covered to keep animals out. Over the few weeks we were able to see how the shoulder’s appearance changed, how it was decomposing, and what insects were present at different stages by using entomology; the use of insects to distinguish PMI.

                Each day we went outside to make observations we noticed changes to the meat. As soon as we placed the meat outside insects had already began to land on it. These insects included blowflies, wasps, blue bottle flies, hairy maggot flies, etc. We also found at dead rat at the scene and we believe it was headed for the shoulder. In our beginning days not much had changed, but more insects were present. On September 10, 2014 the skin of the meat was no longer visible and it was starting to decompose and areas of the shoulder were eaten. The insects were attracted to the wounds in the shoulder and maggot eggs were present. Sept. 14, 2014 marked the day of different odors. Seeing the shoulder had really began to decompose you could smell it. The color of the shoulder shrunk and had faded from pink, to red, to dark red, to black. By the 17^th of September, the only thing left of the shoulder was pretty much its bone. The insects had completely eaten away at the flesh. Maggots were found in each instar and then turned to pupa. Eventually the maggots had developed into adult flies and our experiment was over due to the fact there was nothing else for us to truly observe.

                In order to determine PMI (the time elapsed since the body has been dead to the time it has been found) we needed to collect data. We collected the temperatures from both the shoulder itself to the temperature of the environment we were in. Although PMI and ADH is calculated much more precise by true forensic entomologists we had enough information to get the job done. We compared the data we collected to the published data. Our results ended up being very similar to the published data. The PMI of our shoulder wasn’t very long ago based on our data which was accurate. The instar levels of our maggots proved this to be true. The number of spiracles showed that they weren’t there for very long. Our data was accurate because it was very comparable to the published data.

                Forensic Entomology is a very useful way to solve cases and it has been used to solve numerous famous cases in the world. This process allows you to observe the insects to figure out the time of death and how long ago a death occurred.  Cases that were never thought to be solved have been solved through forensic entomology. Our lab truly expressed how important insects are to solving crimes. Maggots are extremely important and useful when trying to get to the bottom of cases. I agree that bugs are nasty, but they are around the dead and will always leave evidence on bodies to help solve horrid cases. Forensic Entomology makes a difference in the world.

   On September 4th 2014, As a class we started a lab. This lab was to observe insects and learn about forensics entomology. We placed a pig shoulder outside in front of the school along the Blackstone river and observed its changes throughout the upcoming weeks. The main purpose of this experiment was to collect and examine decomposition and the insects that would be collected within the following weeks.
    The first day the pig shoulder was placed outside it simply looked like a piece of meat. The area around the shoulder was surrounded by shrubbery and under shady trees. The shoulder was fresh when first placed outside but over time it slowly began to decompose. On day two of the lab which was two days later the shoulder began to start showing signs of decomposing, it was leathery looking and dried up the temperature around the shoulder was 73 degrees Fahrenheit while the shoulder was 23 degrees Celsius. The twelfth of September the shoulder had began to shrink it was blueish-green, it was the day with the most change present. It had a temperature of 22 degree Celsius. Three days later when the class went to observe the shoulder it had a strong decaying smell and it had turned black. On the last day of the observation the shoulder was completely black and had large mummy looking holes.
      Right when the shoulder was placed outside immediately flies became present, which we all knew would soon lay eggs on the open wounds of the shoulder that we made using scissors. Two days later there were flies, wasps, maggots, inside small larvae, hairy maggot blowflies, green body fly and also sheep blowfly. at this point in the lab the shoulder had been outside for 48 hours. On the coldest day of the experiment there was a rat near the shoulder and that day we collected maggots that were eating at the open wounds of the pig. The upcoming day we also collected more maggots which were in their 2nd larvae stage. Lastly on the 17th their were mainly maggots present eating at the left over meat still left over but also all around the shoulder on the surrounding dirt. Flies were present and maggots where inside the shoulder as well as outside too. The maggots where collected and soon observed.
      In the Entomology lab it thought us that bugs are important to a case and play a major role. They help solve the mystery of when was the victim killed and how long the body was their for. Although things like weather, clothing and the are play a major roll in these issues. All flies follow the same life cycle and that's what leads Entomologist to solve the time of death using their cycle of life.