Forensic Entomology- Life cycle of the Blow Fly

  1. Introduction & Hypothesis:
  2. Hypothesis : I believe that the blow fly process from egg to adult would go faster than the book expected it too. (Click on Hypothesis link to see full hypothesis in detail.)

The importance of this experience is to show how insects help with the decomposition process. Also, this shows how when something dies new life is formed.

The idea of Post-mortem Interval (PMI) is to read and understand the blow fly cycle, someone may have died and determine the time of death from the age of the maggot/blow fly.

Materials & Procedure:

Description: Only after about 8 hours of our raw chicken rotting in the sun, we observed that our chicken had eggs/larva. The eggs and larva are usually found in moist warm areas of the body. These eggs/larva looked like small rice crispy’s. Next in the blowfly cycle is the was the maggot stage, this stage lasts for about 3 days and the maggots feed actively The maggots are hatched from the eggs. Once the maggots are done feeding at around day 5 of the cycle they turn to pupa. Once the pupa’s are done growing they become blow flies. These blow flies are  incapable of flight for the first few hours but then shortly after they are on there way to a brand new life. This whole process is expected to take 21-24 days.


My results of this experimented are embedded in the text of the description.

Here are the measurements of our maggots just before they went into the pupa stage. As you can see they are about 2cm long.


My Hypothesis was CORRECT. It was originally estimated in the text book that the blow fly process would take 21-24 days as shown in the chart. When we went out and did the experiment on our own it only took 15 days.

If I could repeat this experiment I would definitely bring a bigger container to put more chicken in. I would also check the chicken everyday instead of every other day.  To modify this experiment if we could go to an open field and observe the chicken or other animal in the decomposition process. With all of the elements of nature. The experiment would have been more real instead of our chicken being in a container where nothing but flies and other small insects could get to it. Not just insects help with the decomposition process.

I learned so many things from this experiment. I learned that it only takes a few hours for blow flies to lay eggs, and they usually lay the eggs in an opening in the body. I also learned from this experiment is that the smell is very over powering, more than I expected. I had instant watery eyes after smelling the chicken. The most important thing that I learned is that knowing the life cycle of the blow flies can and what stage they are in can tell you how long ago that something had died. You can solve crime scenes like this and it is a very important resource to have.


One thought on “Forensic Entomology- Life cycle of the Blow Fly

  1. You hit all of the major concepts from the rubric, except for a diagram that shows the life cycle of a blow fly. Your formatting could be improved as well and you are missing links to your sources. Still, this is a strong report.


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