Forensic Entomology
Kungu Cake
made exclusively of small midges, Chaoborus edulis, from an East
African lake
["A Natural History of Flies" by Harold Oldroyd (1964)]
Mark Benecke, International Forensic Consultant and Certified Forensic Biologist
Man Bites Bug
All organisms maintain their quasi-stable state of disequilibrium (or life, if you want to be less colorful) by extracting energy from their environment. Unless you are photosynthetic, that energy is available to you only in its chemical form- the vibrations of electrons that are locked in covalent bonds in "complex" molecules. When we eat a hamburger, we are absorbing complex organic compounds, breaking them into smaller constituents, and often recombining the atoms of those molecules with oxygen. This liberates energy from electrons as we drop them to lower energy states in their bonds with oxygen. Proteins and lipids and sugars combine with oxygen to make CO2, H2O, and simple nitrogenous compounds, and the energy made available in this process is used to maintain our body temperature, cellular and tissue structure, and to synthesize new complex organic molecules. All organisms are rife with complex organic compounds themselves, a vertiable Wal-Mart of chemical energy, so it is not surprising that some cultures use arthropods as a food source (see the kungu cake at left). All these years, you have ordered up at Red Lobster, secure in the illusion that lobster and shrimp, coming from the ocean, are more like fish than spiders or scorpions? Think back to your dissections in high school biology. Fish have spines and bones. What class of organism was characterized by a hard exoskeleton that protected soft inner workings, a segmented body, and articulated appendages? Mmmmm, good. I'll just throw another shrimp on the bahbie for you...
Bug Bites Man
Equilibrium is death. Absent oxygen, the generation of ATP, our cellular energy currency, ceases. No ATP? No maintenance of ion gradients essential for cell function, no synthesis of larger complex organic molecules from smaller compounds- stuff happens, boundaries breakdown- and all of that complex organic molecular material is available as a food source for any organism that can make use of it. Nature abhors a vacuum. Life is dominant, persistent, and resilient, spreading like a plague wherever it can find an energy source for a foothold. It is not surprising therefore that arthropods of various sorts have learned to find food in the decomposing remains of organisms that are higher up on the food chain. Some have even evolved a dependence upon carrion availability in their life cycle.
Forensic Biology Bug Bites Man
Did you ever wonder about the romantic life of a forensic biologist? What if you need to write a short story about the dashing deeds and daring dissections of just such a death doctor? It is good to have a model to work from- not every character springs fully grown from our Titan brow; sometimes we need a little kickstart. I bet one could write a whole series of books on material gleaned from the website of Mark Benecke, PhD, International Forensic Hired Gun and Certified Forensic Biologist. Check it out at the left.
Chapters from "The Natural History of Flies" by Harold Oldroyd
A conversation overheard between two wizened and wrinkled fisherman along the gently flowing Thames:
"'Ay, Bertie- w'ot ye got for bait today?"
"Gentles, Bennie- nice big fat juicy gentles that will have trout swimmin' into me basket, leavin' nought for ye and yers today."
"Ahh, Bertie- cleaned out yer kitchen pantry last night, did ye?"
Yup. When used for fish bait or bird feed, the British use the term "gentles" to describe maggots- I guess we all associate maggots with death and putrefaction of animal tissues, so it is not surprising that some might coin a gentler term for fly larvae, allowing a maintenance of social etiquette on the fishing pier.
This association of maggots and flies with decomposition can also be dramatic:
"Taffeta phrases, silken phrases precise, three-piled hyperbole, spruce affectation, figures pedantical - these summer flies have blown me full of maggot ostentation. I do forswear them."
as spoken by Biron in "Love's Labour's Lost" by Shakespeare- here Biron decides that a decomposition of his usual pickup lines into a more simple discourse will yield a higher frequency of success in the dating game. Remarkable imagery here.
Some flies use carrion as a food source for development of their larvae. In 1964, Harold Oldroyd wrote "The Natural History of Flies", a very readable work on fly biology with a strong evolutionary slant. The link to selected chapters of this work is required reading for this class. It is important to understand the biology behind the use of maggots as a forensic tool, and we will explore maggotry in the laboratory ourselves. Oldroyd's work will give us a common foundation for communication as we trap, grow, and examine maggots with an eye towards their utility in forensic science.
Other links at left will support your lab work with flies and maggots. Leave no stone unturned as you seek a comfort zone with the material for this course.