Also Included: Maggot Therapy and Taxidermy Forensic Entomology Also Included: Maggot Therapy and Taxidermy

Forensic Entomology Relies Strongly on the Following Ecological Concepts Developmental time is temperature dependant at the microhabitat level. Ecological succession – A corpse will be invaded by a series of different species or insect groups over time. Each species or group changes the microenvironment through its activities which makes it attractive to new waves of organisms and so on.

The Most Common Application Relates to Death Investigations Determining PMI – postmortem interval Movement of the corpse Manner and cause of death Association of suspects with the death scene Detection of toxins or drugs through analysis of insect larvae

Estimates of PMI Using Insects May Be Based On: Period of time for a given species to reach a particular stage of development Comparisons of assemblages of insect fauna on corpse at time of examination A combination of both above

Most Important Environmental Factors in Corpse Decay* Temperature Access by insects Depth of Burial * Based on study of decay rates of 150 human corpses at U. of Tenn.

Ecological Roles of Insects in Decomposition Necrophages – species feeding on corpse tissue; mostly true flies and beetles; age determination (larval instar) important for PMI Omnivores – insects that feed both on the corpse and associated fauna; ants, wasps and some beetles; may alter rate of decomposition Parasites and Predators – many beetles, true flies and wasps that attack immature flies Incidentals – use the corpse as a resource extension; springtails, spiders, centipedes, some mites

Five Stages of Human Decomposition Have Been Recognized -1 Fresh Stage (Days 1-2) – From moment of death to first sign of bloating; flesh flies, blow flies, ants eating fly eggs and predatory wasps;

Flesh Flies – 2 Species

Two Blowfly Species

Blowfly Larvae

House Flies on Dead Host

Five Stages … 2 Bloated stage (Days 2-6) – putrefaction begins; gases produced by anaerobic bacteria; considerable bloating; seepage of fluids; adult and larval blowflies attracted in large numbers to seepage; soil fauna moves away due to wetness of earth; ants and other species of flies prey on maggots

Five Stages … 3 Decay Stage (Days 5-11) – Abdominal wall is broken and carcass deflates; adult flies begin to leave but great masses of maggots remain and feed; carcass will begin to dry and beetles begin feeding on drier tissue; flies start to pupate; predatory beetles such as rove and hister beetles are attracted

Pig Carcass Infested With Blowfly Maggots

Hister Beetles Prey on Blowfly Larvae

Rove Beetles – 2 Species

Five Stages … 4 Postdecay Stage (Days 10-25) in dry habitats - remains consist of dry skin, cartilage and bones; site for dermestid beetles, histerids, fly pupae, immature and adult rove beetles in wet habitats – large quantities of wet, viscous material (byproducts of decomposition) found in soil under the remains; site for adult and immature moth flies, rove beetles

Dermestid Beetles – Adult and Larvae

Five Stages … 5 Dry Stage (Days 25+) – Mainly bone and hair is all that remains; odor is primarily that of soil and litter; some dermestids, fly pupae, immature and adult rove beetles, normal soil fauna consisting of mites, etc. start to return; this stage could last for several months to years

Carrion Beetles – 2 Species

Rat will be completely buried and eggs laid upon it. Female Carrion Beetle and Kangaroo Rat Rat will be completely buried and eggs laid upon it.

Barriers to Decomposition and Irregular Decomposition Physical – soil, water, caskets, antermortem and postmotem injuries Chemical – embalming agent, insecticides, lime, etc. Climatic – heat, cold, wind, rainfall Animals – bird, mice, rodents, canids, cats, etc.

Maggot Therapy – Technically called Maggot Debridement Therapy or MDT Fly larvae are used to scavenge on dead tissue associated with a wound. Fly larvae excrement, termed allantoin has a high ammonia content which appears to serve as an antibiotic.

Wounds on the Battlefield in World War II It has been noted by war surgeons that wounds incurred by troops in which fly larvae were feeding had much less gangrene and healed more quickly than wounds that were protected from flies …

Phaenicia sericata – the green blow fly Phaenicia sericata – the green blow fly. This species feeds only on necrotic (decayed) tissue.

Interesting and True … Maggot therapy is much more commonly used in Great Britain and Europe than in the U.S. There have been about 25,000 treatments in Great Britain since 1995. Ronald Sherman, M.D. is the pioneer of maggot therapy in the U.S. He is located at U. of Calif., Irvine.

Maggots Feeding at Edge of an Ulcerating Wound on Foot

Maggots Cleaning Up a Wound Associated with an Amputation

Vertebrate Biology/Taxidermy – Skull and Skelton Preparation

A Skull Cleaned by Dermestid Beetles

Trays of Vertebrate Skulls in Dept. Of Vertebrate Biology, Univ Trays of Vertebrate Skulls in Dept. Of Vertebrate Biology, Univ. of Michigan

A Great Horned Owl Skeleton

Dermestid Colony Housing

Larval and Adult Dermestids Working on Jawbone

Bear’s Skull Being Cleaned

Dermestid Beetles Are Economic Pests and Will Scavenge on Anything Organic of Both Plant and Animal Origin Destroy woolen carpets, upholestry and rugs Consume insects on pins in museum and university collections Stored furs, leather and skins Meat, cheese and stored products Materials made of silk

Dermestids are Beneficial in Terms of Their use in vertebrate skull/skeleton collections Their forensic use as we have seen