|
1. |
|
|
|
|
2. |
|
|
|
|
The first insects arrive at the corpse attracted by the smell of gases that are released in the process of degradation of the immediate principles, gases such as ammonia, sulfuric acid, free nitrogen and carbon dioxide.
Long before humans can detect it, insects detect these gases and are attracted to the corpse, depositing eggs in the natural orifices of the body, thus beginning the cycle.
There are two methods to determine the time since death using entomological evidence: the first uses the age of the larvae and the rate of development; the second method uses the succession of insects in the decomposition of the body
|
|
3. |
|
|
|
|
Musca domestica are the first to arrive on a corpse; a female can lay up to 150 eggs.
Their life cycle makes it possible to determine the post-mortem interval, considering the time it takes them to move from one stage to another.
Muscid flies will visit a body soon after death, attracted by any exudates rather than the corpse itself, It is characterized by four narrow black stripes along its thorax and a greyish or yellowish abdomen.
Calliphora vomitoria females lay their eggs on the corpse; but also in open wounds, their cycle lasts about 2 to 3 weeks (depending on weather conditions) and they have a great devouring capacity in the process of decomposition.
The larvae of these diptera destroy superficial tissues, creating the first cavities that act as entrance doors for other species to reach deeper areas
|
|
4. |
|
|
|
|
Lucilia caesar arrives when they perceive the cadaveric odor, when putrefaction settles in the gaseous phase.
Both the thorax and abdomen of Lucilia caesar have a very bright metallic green color.
Females lay several hundreds of eggs that develop very fast, because in good conditions they can hatch in only 18 hours.
Lucilia sericata is a fly of necrophagous feeding habits, and one of the predominant species in the cadaveric fauna, is commonly called a greenbottle because all the flies in this genus are a metallic green color. Lucilia species are distinguished from other blowflies by having a ridge just above the squama, the rear wing, which has tufts of hair on it.
|
|
5. |
|
|
|
|
The Sarcophagidae family lives exclusively on corpses and does not lay eggs, but deposits live larvae.
Sarcophagids have developed a reproductive strategy called larviparism, their eggs develop in the abdomen of the female, when she lands on the corpse, she releases the larvae and these, after a day of development penetrate the flesh and devour it until they enter the pupal stage, the sarcophagids pupate between clothes or in the folds of the body and take advantage of the natural orifices for their clutches.
In general, adults of this family arrive at the corpses after the calliphorids. They are known to be able to fly in adverse environmental conditions, which give them an advantage when arriving at a dead body.
|
|
6. |
|
|
|
|
The third squadron occurs in the period of butyl putrefaction, that is, when there are acidified fats, three to six months after death. It is composed of Coleoptera and Lepidoptera.
Among the Coleoptera, the Silphidae are the group with the greatest incidence in the destruction of corpses, and in some ecosystems their action is comparable to that of Diptera. They are a group of Coleoptera perfectly adapted to live on carrion, completing their entire biological cycle on it.
The fourth squadron corresponds to the period of butyric and gaseous putrefaction, that is, of acidified fats and proteins, and is composed of Diptera and Coleoptera.
The fifth squadron is attracted by ammonia fermentation and is composed of several genera of Diptera.
|
|
7. |
|
|
|
|
In the sixth squadron they are in charge of absorbing the liquid humors left by the previous squads, so they desiccate and can mummify the still existing organic tissues, constituted by several insects of the genus Acariano.
The seventh squad occurs when there are only mummified remains that do not allow the fermentative ones to act. They correspond to Coleoptera and Lepidoptera.
The eighth squad is composed of two species: Tenebrio and Ptinus.
The workers of this squadron have the mission of absorbing the liquids that may still exist in the corpse, remains of putrilago, finishing by desiccating or mummifying the parts that have been able to resist the destruction of the previous squadrons.
|
|
8. |
|
|
|
