Dirt, Worms and Maggots

COMMON INSECTS OCCURRING ON DEAD BODIES

Acari

The Acari, or mites as they also are called, are small organisms, usually less than a mm in length. Mites occur under the dead body in the soil, during the later stages of decay. Many mites are transported to the body via other insects, such as flies or beetles. Other mites are soil dwelling forms which can be predators, fungus feeders or detritus feeders. Most species will be found in soil samples from the seepage area under the body.

Aranea

The Aranea or spiders are predators on insects occurring on bodies. No species is specific to the carrion fauna, and will have limited or no value in estimation of the PMI.

Diptera

The order diptera contains insects with one pair of wings, the second ones modified to halteres. About 100,000 species are known to science, many more awaits discovery. Among the flies we find many members of the carrion fauna. The larvae of flies lives in very different habitats, also aquatic.

NEMATOCERA

Trichoceridae

Trichocera sp.
or winter-gnats as they also are called because the common species Trichocera regelationis, T. saltator, T. maculipennis, etc, fly abundantly in the winter months, although they occur at lower frequencies throughout the year. The adults resemble small crane-flies. The larvae are saprophagous and feed on decaying material. Trichocerid larvae constitutes an important part of the carrion fauna during the winter months, when the blowfly fauna are missing.

BRACHYCERA

Stratiomyidae

Larvae of Hermetia illucens is recorded eating on human excrement and human remains. Usually this species occur late in the decomposing process.

CYCLORRHAPHA-ASCHIZA

Phoridae

A large family of flies, containing about 3000 species. They are minute to medium-sized (0.75-8.00 mm), dull black, brown or yellowish flies of hump-backed appearance. They are generally bristly and with a very characteristic wing venation. They run about in an active erratic manner which has earned them the popular name of scuttle-flies. They breed in a wide variety of decaying organic material, in addition some develop in fungi and others are parasites. In the larval stage some species are predators. Several genera is regularly found in vertebrate carrion e.g. Anevrina, Conicera, Diplonevra, Dohrniphora, Meopina, Triphleba and some Megaselia species.

Conicera tibialis also known as the coffin-fly because of its association with coffined bodies that have been underground for about a year. Adult C. tibialis is able to bury to a depth of 50 cm in about four days. At normal grave depths (1-2 m) temperature variation is slight, about 5 degrees Celsius, so development from egg to adult will take considerable time. Development can take place independent of season, since the body is buried at frost free depth.

Syrphidae

These are the familiar hover flies, often camouflaged as wasps or bumble bees. Among the larvae of syrphids we find the famous rat-tailed maggots. These occur in filthy water, and may occur in dead bodies.

ACALYPTRATAE

Dryomyzidae

A small group of relatively rare flies. Most species are found in moist woods. Their larvae occur in decaying organic matter.

Coelopidae

These flies are small to medium-sized, usually dark-brown or black in color, and have the dorsum of the thorax flattened. The body and legs are very bristly. They occur along the seashore and are very abundant where seaweeds have washed up. Occasionally larvae may develop in other organic matter, such as a dead body which has been lying along the seashore.

Heleomyzidae

Fairly large group of small to medium-sized often brownish flies. Adults are often found in moist places, larvae in decaying plant or animal matter, or in fungi.

Sepsidae

Very characteristic flies when alive, the adults occur in large numbers around excrements and decaying materials, where the larvae develops. The adults have a peculiar habit of wing-waving. This family have been recorded feeding on dead human bodies in the time of caseic fermentation and before ammoniacal fermentation. Eggs of Sepsidae have a very long respiratory horn, often longer than the egg itself.

Sphaeroceridae

Minute or small dark flies that breed in dung.

Piohilidae

Dark, shining flies. The larvae are scavengers and are often found on dead bodies that have been lying for a while. Piophila casei is also called the Cheese-skipper, because the larvae jumps for a considerable height, when disturbed. This behaviour is probably a defencive tactic against predators. These flies also infests stored bacon and cheese, which, to the flies, are almost the same as dried corpses.

Ephydridae

Large group with several common species. They are small to very-small. Adults are found in moist places: marches, the shores of ponds and streams, and the seashore. The larvae are aquatic, and many species occur in brackish or even strongly saline or alkaline water.

Drosophilidae

These are the well-known fruitflies that every biologist have heard about, and probably most other people too. Minute and small flies, brown, yellow or grey with brightly colored eyes. The larvae feeds on decaying vegetable matter, but some also feed on fungi. Some species may occasionally occur on dead humans, and these are probably feeding on fungi.

Milichiidae

Minute, dark flies. Adults and larvae are scavengers.

CALYPTRATAE

Sarchophagidae

Among the Sarcophagids we find the large flesh-flies with red eyes and a grey-checkered abdomen. These flies does not deposit eggs, but larvae on the corpse. They are, together with the Calliphorids, among the first insects to arrive at the corpse. The larvae are predators on blowfly larvae, as well as carrion feeders. Many Sarcophagids are feeding on snails and earthworms.

Calliphoridae

These are the famous green-bottles and blue-bottles. There is many species of blowflies, and each species has their own biology. Some prefers to oviposit in shade, others in light. Some are mainly urban in their distribution, others mainly rural.

Fanniidae

Here we find the lesser house-fly, Fannia canicularis among others. These flies are mainly breeding in faeces, but can also develop in cadavers, especially if there are patches with semiliquid tissue. The larvae have fleshy processes all over the body, which assist in floating.

Muscidae

Among this large family we find the common house-fly, Musca domestica. These flies occur in houses, and are one of the most widely distributed species on this planet. In warm weather they can complete development in 14 days. Eggs are laid in decaying material, including, but not limited to, dead bodies.

COLEOPTERA

Several beetles occur on carrion. There exists necrophagous beetles and predators. The various groups occur in different stages of decomposition.

Staphylinidae

Staphylinids - or rove-beetles may arrive a few hours after death, and remain active throughout the decomposition process. The adult and larvae feeds on eggs and larvae of other species. They have a characteristic short elytra.

Dermestidae

Dermestids are common beetles in the later stages of decomposition. Larvae of dermestids does not occur before the body is dry. The larvae and adults feeds on dry skin and hairs and other dry dead organic animal matter. Dermestids is a common stored product pest in homes, and a pest in insect collections and furs at museums and other places.

Histeridae

Members of this family has short elytra, but not as short as the Staphylinids. This family occurs wherever there is decay and putrefaction. They have been found during the bloated, decay and early parts of the dry stage. Both larvae and adults feed on maggots and puparia. They are usually concealed under the corpse during daylight, but becomes active in the night. Saprinus and Dendrophilus occur on dead animals and on air-dried and smoked foods. They prey on larvae of Dermestes.

Silphidae

In this family we find the Nicrophorus species, well known for their habit of undertaking small carcasses. Some of the species of Nicrophorus lives mainly on larger carcasses, and does not bury them. The adults prefer feeding on maggots, but also feeds on the carrion. The adults feed their larvae until pupariation. Easton reports that 13 specimens of Necrodes littoralis was found on the body of a man which had been lying on the North Downs for 17 days in October 1969.

ORIGIN: https://folk.uio.no/mostarke/forens_ent/common_insects.shtml