The Acari are one of the most ubiquitous arthropod inhabitants and associates of human and animal remains. Over 150 years ago, Jean Pierre Mégnin proposed that mites arrive at corpses at two particular stages of the decomposition process, that is within the first and the sixth waves of arthropod arrival or colonisation event (Mégnin, 1895). Now we know that mites actually arrive at each stage of the decomposition process of corpses, in a continuum (Rai et al., 2021). Interestingly, the mite fauna of cadavers is very diverse, and mite species composition varies as decomposition progresses and according to the environment where decomposition occurs (Baker, 2009; Braig & Perotti, 2009). In fact, specific stages of decomposition can be characterised by the associated mite species (Kamaruzaman et al., 2018; Leclercq & Verstraeten, 1988; Mašán et al., 2013; Mégnin, 1895).
In terms of the environment where a corpse decomposes, if on a soil surface, outdoors, it will attract epigeal and hypogeal mites and a variety of carrion insects, which will bring their own phoretic mites (Fig. 1-A). Mites travelling on insects or small rodents are the most common and ubiquitous arthropods arriving on remains (Perotti & Braig, 2009; Perotti et al., 2010). Some carrion insects, like beetles, are able to transport several species and a great number of individuals, up to the hundreds or thousands. For example, silphid beetles are able to bring species of Parasitidae, Macrochelidae, Melicharidae, Uropodidae, Histiostomatidae, Acaridae at the same time—just to name some of the most common families of phoretic mites brought to a corpse (Perotti & Braig, 2009).
Opportunistic insects visiting or colonising, somehow taking advantage of the corpse (Byrd & Castner, 2009), for example, a queen bumblebee using part of it to build its nest, will bring too its diverse phoretic mites (Klimov et al., 2016). Ticks, although opportunistic, are also assiduous visitors of the decomposition environment (McNemee et al., 2003). They need to be nearby, ready to jump on the next host approaching the decomposed body, likely a scavenger or a forensic investigator. This is becoming so frequent that in Europe, the widespread species Ixodes ricinus utilises carrion and coprophagous beetles moving to and from carcasses to secure availability of hosts (Salona-Bordas et al., 2015).