First Interaction Network of Sarcosaprophagous Fauna (Acari and Insecta) Associated with Animal Remains in a Mediterranean Region (Northern Spain)

SIMPLE SUMMARY: Forensic entomology applies the knowledge of arthropods to obtain useful information for the resolution of forensic investigations. In legal medicine, one of the methods used for the dating of death is the faunal succession, which is based on the orderly and predictable changes of the species associated with a corpse over time. The potential of insects for this purpose has been known for more than seven centuries, but mites are only currently being incorporated. Mites can provide useful information on the time and place of death because: they are a very diverse group, ubiquitous, abundant, and frequent; they contribute to the faunal succession; they are indicators of location and transfer of the corpse; they can be present in unfavorable conditions or environments for insects; they complement the information obtained from insects; and they are tracking evidence. Due to the absence of knowledge regarding the sarcosaprophagous fauna in the Mediterranean region, it is necessary to highlight the diversity of insects, together with their phoretic mites, present in decomposing animal organic matter, and their interaction network in this region, in order that the results obtained can be applied in future forensic investigations and contribute to the estimation of the time and place of death. ABSTRACT: The potential of insects for forensic investigations has been known for more than 700 years. However, arthropods such as mites could also play a role in these investigations. The information obtained from insects, together with their phoretic mites, is of special interest in terms of estimating the time and geographical location of death. This paper presents the first interaction network between phoretic mites and their host insects in Navarra. It also reports the first time that an interaction network was applied to animal remains of forensic relevance. The data reveal the degrees of specificity of the interactions established, the biological and ecological characteristics of the mites at the time of association, and factors that played important roles in the mites’ dispersion. Fauna was collected using 657 traps baited with 20 g of pig carrion over a year. Only 0.6% of insects collected carried phoretic mites. The network comprised 312 insects (275 beetles, 37 flies) and 1533 mites and was analyzed using various packages of the R programming language. We contribute new host insect records for 15 mites, 3 new records of insects as hosts, 5 new mite records for the Iberian Peninsula, and 2 new mites records and 8 new insect records for Navarra.