Death Scene Insects

carrion beetle

Carrion Beetle (Necrophila Americana)

The Carrion Beetle is relatively large, rounded in form, and has a yellow pronotum with a black central spot. Larvae feed on carrion, particularly the drier parts such as hide and sinew. The adults feed primarily on the larvae of flies found in carrion, as well as on the carrion itself. This specie of carrion beetle is found primarily in the eastern United States.

dermestid

Dermestid Beetles (Family Dermestidae)

This group on insects includes skin or hide beetles, carpet beetles, and larder beetles, some of which can be serious pests of closets and pantries. The name dermestid comes from the word for skin. Adult dermestid beetles are quite small, ranging from just 2 mm to 12 mm in length. Their bodies are oval and convex in shape, and sometimes elongated. These insects are covered in hair or scales, and bear clubbed antennae. Dermestids have chewing mouth parts. The lavae are worm-like, and range in color from pale yellowish brown to light chestnut. Like the adult dermestids, the larave are hairy, most noticeably near the hind end. The larvae of some species are oval, while others are tapered.

carrion beetles

Carrion Beetles or Burying Beetles (Order Coleoptera)

These insects are a part of the family of beetles known as Silphidae.  There are two  subfamilies: Siliphinae and Nicrophorinae.  Both feed on decaying organic matter such as  dead animals.  The families differ in terms of parental care and carcass preferences. Silphids are usually not considered a nuisance to humans  because they break down decaying organic matter, which prevents accumulation of  deceased organisms.  Silphidae larvae are opportunistic predators that will feed on dipteran  eggs, larvae, and on the carcass itself.

Soldier Fly

Black Soldier Fly (Hermetia spp)

Adult flies are robust, approximately 5/8 of an inch long, with smoky black wings.Wings are held over the  back when at rest.  Adults superficially resemble wasps, but have no stinger and are harmless.  Larvae are typically robust and feed on decomposing matter, mold, and algae.  The use of soldier  flies in estimation of postmortem interval is still an emerging area of study but show some promise  for forensic entomologist.

Blow Flies

Blow Flies (family Calliphorideae)

The insects of greatest value for forensic entomologist are blow flies.  They are  usually the first insects to colonize a body after death, often within hours. Because of  this, the age of the oldest blowflies gives the most accurate evidence of the Postmortem  Interval (PMI). Blowfly infestations of human bodies are a natural outcome, but they are a  vital component of the natural recycling of organic matter.  On human bodies they can  provide vital clues to the timing andcause of death. Blow fly eggs are usually laid in the natural orifices (e.g. eyes, nose, mouth, ears) or other dark  and moist places, such as the folds of clothes or just under the body.  Eggs hatch into first instar larvae that grow rapidly, moulting twice to pass through second and third instars until they finish feeding. Depending on the species, they pupate on the body or move away to find a suitable site.  They may move many feet before burrowing into the soil or under objects such as, rocks and logs or if indoors, under carpets and furniture. The rate of development of these insects is directly dependent on the ambient conditions, particularly temperature.  Once the ambient temperatures are known during the period of development, then, in theory, the minimum PMI can be determined.

Posted on: April 30, 2014 by