Forensic Entomology: Spring 2015

The pigs are out!

Two stillborn pigs were placed this morning at approximately 9:30am.

Nearby Weather Conditions:

High: 64 F

Low: TBD

5cm Soil Temp: 58.54 F

Wind: Breezy, avg 5mph

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Very few eggs found. Ant activity may be obscuring actual numbers due to predation.

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Decomp Project: Full Meal Deal

Remember that groundhog I placed out there two weeks ago?  Anyone have a guess as to what happened to it?  Well, it went all pancakey that’s what!  Pancakey…that’s the official scientific term for it.

Who wants to guess how long it took?  Here’s a video I put together including some images and video I took of the process.  You might be surprised by what you will see visiting the remains.  Now, before you watch this, I want you to take a guess as to how long it took to go from fresh to skeletonized.

Decomposition Study: Day 2

When I left work last night (about 6:00pm) I took some updated photos and posted them. This morning after pulling in I took a look and snapped a pic of our groundhog.

You can definitely see a change in the size of the little guy within this first day. She’s quite bloated and there is evidence of bacterial action. The bloat is caused by the exponential increase in the amount of bacteria normally found in the body. Just like humans, this groundhog, once it ceased to breathe and circulate blood through its body, was no longer keeping the bacteria and fungi at a standard level. Now, they’re just reproducing like crazy, causing gasses to form. Sometimes these gasses can cause weak areas of the body and places that have been damaged to rupture and internal organs and fluids will push themselves out (see below image of the pig) but normally these gasses will escape through natural openings on the body like the mouth and anus. When I moved this little groundhog boy did I get a whiff!!!

Day 1 Full Body 11:00am

Day 1 Full Body
11:00am

Day 2: Full Body 9:00am

Day 2: Full Body
9:00am

From an undergraduate research project.  Day 2, gasses have caused a perforation through a weakened spot on the abdomen of this pig.  Intestines have pushed through.

From an undergraduate research project. Day 2, gasses have caused a perforation through a weakened spot on the abdomen of this pig. Intestines have pushed through.

You can see in the below image a group of Blow/Bottle Flies (Calliphoridae: Diptera) congregating around the snout. Yesterdays image taken about 8 hours after placement shows some bubbling of fluids and gas in the nose. Today’s image, almost 27 hours after placement, shows the bubbling continues with maggots (fly larvae) on the other side.

Day 2: 27 hours after placement. Adult blow flies congregate around the nose.  Maggots in foreground.  1rst instar blow fly larvae.

Day 2: 27 hours after placement. Adult blow flies congregate around the nose. Maggots in foreground. 1rst instar blow fly larvae.

Day 2: 27 hours after placement. Adult blow flies congregate

Day 2: 27 hours after placement. Adult blow flies congregate

I also have found more egg laying locations including in the lip (below – as expected) and on the underside of the body at the point of interface with the soil.

Day 2: 27 hours after placement. Eggs under the lip and snot-blood bubbles in the nose.

Day 2: 27 hours after placement. Eggs under the lip and snot-blood bubbles in the nose.

Soil Temp: 90F
Interface Temp: 80F
Mouth Temp: 100F
Calliphoridae: 10+ adults; 50+ larvae; 100+ eggs
Staphylinidae: 1 adults

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Forensic Entomology: Decomposition and Then Some

So, what is Forensic Entomology?  When someone says those two little words the first thing that pops into most peoples minds is Grissom from CSI.  Interesting though he may be (and loosely based on an actual Entomologist, Dr. Neil Haskell and Acarologist Dr. Lee Goff) there’s more to it than that.  Forensic entomology is more than just analyzing dead stinky stuff.  There are actually three different subfields of forensic entomology: Urban, Stored Product Pest and Medicolegal Entomology.  Medicolegal is the most commonly thought of branch but it is actually the branch that sees the least amount of use.  Termite cases comprise the vast majority of legal cases related to entomology and that’s what “Forensic Entomology” is: The application of Entomology, insects and other arthropods to legal issues.  This can be civil and criminal.

Think about how much you hear about bed bugs or carpenter ants, maggots, or bees in the news!  Aunt Sally went to that fast food restaurant and found a maggot in her burger?  Lawsuit! Bed bugs infesting an apartment complex that was supposed to have been treated?  Lawsuit!  New home owners have a termite problem but none was found by the initial inspection or disclosed by the original owners?  You bet there’s gonna be a lawsuit. Though very different in focus, all are examples of forensic entomology.  I happen to think that each has its fascinating points as well as wildly boring ones as well.

For your viewing pleasure, over the next few days I am going to walk you through the process of decomposition as it unfolds in my front yard.  I found a recently biffed groundhog and just placed it out this morning.  Over the coming days I’ll post pictures and some analysis of what is happening to the groundhog over time.

Day 1 Full Body

Day 1: Full Body
approx. 11:00am EST

Day 1: Head and forelegs

Day 1: Head and forelegs
approx. 11:00am EST

Day 1: Posterior

Day 1: Posterior
approx. 11:00am EST

**Edit** Added Images Later in the Day

Full View approx. 18:00 (6pm) EST

Full View
approx. 18:00 (6pm) EST

Eggs on lower abdomen approx. 18:00 (6pm) EST

Eggs on lower abdomen
approx. 18:00 (6pm) EST

Forensic Entomology: Decomposition Study

What’s an entomology grad student do for fun you might ask?  Well, drive around and pick up road kill!  Doesn’t everyone!?!  This poor groundhog has seen better days though I doubt he remembers them.  Placed in my little bone yard this little fella has provided a nice feast for the local flies and beetles.  See below for some images and a short video of that sweet Snap-Crackle-Pop music!

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Vertebral column and pelvic girdle of a groundhog thoroughly covered in fly larvae. These are most likely Calliphoridae larvae (bottle/blow flies). The larvae pack themselves tightly so as to conserve space and better regulate their temperature.

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Closer up of the larvae. Their mouth parts are facing down so they can chow down while their butts are facing up so they can breathe through their two posterior spiracles! Those spiracles are extremely useful, not just for identifying their age but also the species.

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Awh….Bug Love. Mating pair of carrion beetles (Silphinae: Silphidae). Wherever there is rotting flesh, there you will find mating carrion beetles. Most beetles don’t come along to eat the remains themselves but rather the fly larvae. Not these guys. Along with Dermestid (carpet/hide) beetles, these will eat the larvae and the carcass!

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Look at how nicely those bones have been cleaned up for me! Insects are sure helpful! What you are seeing is the proximal end of the ulna and radius as well as the distal end of the humerus. I swear, the humerus is one of my favorite bones. It just looks so pretty. I especially like cervid humeri.