Colonisation
There are hundreds of different species of necrophagous insects. Here are some of the major families:
Calliphoridae, Sarcophagidae
Calliphoridae (blowflies) and Sarcophagidae (flesh flies) are the first families of insects to colonise on a body (Goff, 2009) as their eggs and larvae require moist tissue to develop (Introna F, 2000). Insect growth rates differ at different temperatures. For the blowfly species Calliphora vicina, at 23.3°C the first instar is present from 21 to 29.5 hours after death, the second from 45-52 hours, the pupa from 202.8 to 279 hours, and the adult from 454 to 499.5 hours (Amendt et al., 2004).
At the bloated stage of decomposition, from 2 to 6 days after death, the corpse is dominated by maggots. By the end of the post-bloated stage, from 5 to 11 days, most maggots leave for pupation. (Goff, 2009). |
SilphidaeSilphidae (Carrion beetles) also colonise carcasses which are freshly dead. Their larvae have been found on corpses within 4 days of death (Midgley and Villet, 2009). Midgley and Villet (2009) studied the development times of the carrion beetle Thanatophilus micans and found that at 17°C they take 29.5 days to develop from oviposition to pupation, and at 25°C, 15.7 days. At 25°C egg development takes 3 days, and development from egg to adult takes 22.2 days (Midgley and Villet, 2009).
|
MuscidaeLefebvre and Pasquerault (2004) studied the minimum durations of each developmental stage in Ophyra aenescens, of the family Muscidae (Muscid flies). At 24°C, the eggs are present from their first appearance for a minimum of 20 hours, the first instars for 46, second instars for 40, third instars for 124, and pupae for 168 hours (Lefebvre and Pasquerault, 2004).
|
DermestidaeDermestidae (Dermestid beetles) are present on a corpse from the post-bloated stage, from 5 to 11 days, they feed on the skin and ligamentous tissue (Braack, 1987). The male beetles arrive first, attracted to the odour of benzyl butyrate produced by decomposition, which occurs at its highest concentration at this stage. The females arrive after the males, attracted to the combined odours of benzyl butyrate and male sex pheromones. The first Dermestid larvae start occurring at the advanced decay stage from 10 to 25 days, and larval development is completed in the dry-remains stage, from 25 days after death. (Hoermann, 2012).
|