Friday, 27 September 2013
09:16:47 PM (GMT)
Note: All times were made in military time
Lab Report – Insects on and Around Dead and Decaying Flesh
(The Demise of Porky the Pig)
Date Span: 4 September 2013 to 13 September 2013
We conducted an experiment to observe the fly’s life cycle and how a pig’s foot
would decompose due to the environment and scavengers. Conventional theory states
that flies will be attracted to the smell of decaying flesh within a short time of
the animal’s demise. Given that the development of the flies proceeds at a known
rate, it is possible to determine how long the foot has been left based on the stage
that the observed maggots have developed. Previous observations by scientists have
given us data on how long it takes for the eggs to hatch and develop. This is also a
function of the ambient temperatures at the time. The flies when landing on the
pig’s foot would lay eggs in the moist parts of the flesh. The eggs then hatch into
larvae called maggots. Maggots are important because they pertain to forensic
entomology. Forensic entomology helps us to obtain the time and date of death. In
order to determine the post mortem interval we need to determine which species of
flies are developing at the time of evidence collection. It is possible to identify
the species of the fly by looking at the development of the maggots and the final
description of the fly. Different species of flies develop at different rates. When
brought back to the lab we determined flies that were starting to grow into stages
I., II., and III. We observed that most maggots were in stage III of development.
Our foot was 19.05 centimeters long, 8.9 centimeters wide, and 5.4 centimeters deep;
labeled “Dinner.” We chose a pig’s flesh as a medium because it closely
resembles that of a human. We left the specimen in dirt on top of bark and leaves.
The area was mostly sunny throughout the day. The immediate ground around the leg was
cleared, however the leg was surrounded by bushes and trees.
We left the specimen in a small cage for 8 days. The cage was staked into the ground
and was used to keep scavengers from hindering our experiment. We recorded our
findings each day along with the specimen’s temperature and the appearance of
After the allotted time, on 13 September 2013, dirt samples were collected from our
area and a fly (green-yellow eyes) was caught. Maggots and a fly (orange-red eyes)
were collected from a different specimen site approximately 10-15 feet away.
4 September 2013: 1400 – 13.8 C
We placed the pig’s foot out in the chosen area.
5 September 2013: 1330 – 39.5 C
We noticed flies were landing on and around our leg along with the new presence of
ants. Ants had made a hole through the foot. The flesh had looked darker (more
pink/red) and wrinkled. Our specimen had a slight odor but was not pungent.
6 September 2013: 1405 – 40.6 C
We found the amount of ants had dissipated however there was an increase in flies.
When the leg was flipped we discovered small maggots approximately 2mm in size. The
flesh at the toe end of the specimen had shrunken off, and the bone was exposed (more
on the right side than the left). Dryer skin, yet the specimen was glistening. The
leg had been moved and the toe was sticking out of the cage which suggests a
scavenger had attempted to take it.
9 September 2013: 1333 – 48.3 C
Plentiful well-fed maggots were found. There was an absence of all ants and few small
flies were around and on the leg. The skin was a harsh magenta colour. Muddy from the
leg’s decaying flesh juices, and cavernous from the maggots feeding off the inner
flesh. Flesh looks leathery.
10 September 2013: 1426 – 40.1 C
A new ant trail had formed leading off to a different direction than the previous
trail. Well-fed, plump maggots about a centimeter in size were eating the flesh of
the specimen. There were significantly less maggots than September 9. Foot was
flipped over with the bone exposed. The flesh had started turning black.
11 September 2013: 1409 – 32 C
No maggots were found. Ants were crawling around the specimen but not many were on
the leg. A fur patch, with skin attached, was found near our cage which suggests
scavengers fought over the specimen; could be the cause of the insect absence. A
potent smell was coming from the specimen. The specimen was found on its side.
12 September 2013: 1403 – 39.9 C
All insects were missing from the specimen. Leg looked shrunken and very dry. A deep,
dark colour and a hard leathery texture covered the remaining flesh.
13 September 2013: 1334 – 39.6 C
Our specimen was rough and dry inside and out. We encountered difficulties while
trying to take the temperature, but got an accurate read. There was still an absence
of insects on the foot however there was an increase of bees in the specimen’s
general vicinity. Flies were flying around the area but were not landing on the foot.
Our specimen looked mummified.
(Maggot observations were not done.)
• "Entomology." Museum of Archaeology and Ethnology. N.p., n.d. Web. 27 Sept.
Last edited: 27 September 2013