Carrion insects
Although specific arthropod species present at remains will vary by geographic location, some examples of common blowflies are Calliphora vicina, Phormia regina, Protophormia terraenovae and Lucilia sericata Necrophagous blowfly species are often the first to arrive and colonize at a site of decomposing remains.
[2] These species develop from eggs laid directly on the carcass and complete their life cycle on or near the remains.
[4][5] The initial colonizers of greatest importance are those of the family Calliphoridae, Sarcophagidae and Muscidae (house flies), as these are typically the first insects to lay eggs at remains.
These insects do not feed directly on the decomposing remains or its fluids, but are considered to be the second most forensically important ecological role.
[3] The majority of beetles present at remains are there as predators of blowfly larvae, and are not directly concerned with the removal of carcass materials.
[6] Predaceous beetles may arrive at a site of remains as early as the bloat stage of decomposition, when there is a strong attraction of their necrophagous prey.
Arthropods in this ecological role are not necessarily attracted to decaying remains, but use it as an extension of their natural habitats.
The predictable order in which the above described insect groups are attracted to and observed on remains is referred to as a succession pattern, and can be used in forensic investigations to estimate the post-mortem interval (PMI) or time since death.
[12] A second method of PMI determination, in early stages of decomposition, by insect evidence utilizes the development rate of colonizing arthropods.
