LABOULBENIALES - Agentschap voor Natuur en Bos

4. DISCUSSION4.1. METHODSAlthough forensic entomology is used to aid murder investigations, only fewrecent literature results on observing cadavers is available. However, theknowledge obtained from this kind of research (in combination with dataconcerning the development of the different species) is necessary in order toestimate the (minimum) post mortem interval (PMI) and consequently the timeof death (ASISTM, 2009).Forensic entomology is generally a field concentrating on Diptera. Manycoleopterans also have forensic applications, but are often neglected byforensic entomology researchers (MIDGLEY, 2007). It is important to realize thatthe collection of Coleoptera is both semi-qualitative and semi-quantitative,since they run away with the least interference (VAN WIELINK, 2004). Also theweather has some great influence on decomposition and thus the populationsof insects. In this research, for both the experiments in the Sonian Forest andthe Meerdaal Forest no details concerning the weather have beenconsidered.4.2. IDENTIFICATION OF BEETLESThe identification of a few specimens took place only to genus level. This holdsfor Anaspis (Scraptiidae), Aphodius (Scarabaeidae), Cantharis (Cantharidae),Oxypoda (Staphylinidae) and Ptiliolum (Ptiliidae). Identification to species levelrequires the fullest understanding of the respective genera, including specificshapes of the male reproductive system, minor differences between tarsalsegments, … For example, the genus Aphodius comprises 86 species in 27subgenera, classified according the shape of the hind tarsi, the shape of thehead and the morphology of the male reproductive system.One of the problems for forensic investigators is the accurate identification ofthe larvae collected from a corpse. For this research, the identification ofSilphidae larvae was based on the identification key in KLAUSNITZER (1997).However, according to this identification key some characteristics of thelarvae corresponded with Necrodes, other with Thanatophilus. Even more, thewhole table of Silphidae larvae in KLAUSNITZER (1997) is problematic (pers.comm. HANS HUIJBREGTS, 2010). The larvae were finally determined as Necrodes(littoralis), based on their size. (The studied larvae were larger than mostThanatophilus adults.)The identification of Thanatophilus species is not evident. Thanatophilusrugosus is recognizable by its wrinkled elytra. Both T. dispar and T. sinuatus aredifficult to distinguish. Since T. dispar is rare (since 1960 only two observations inThe Netherlands; no observations found in Belgium), we could suggest ourspecimens to be T. sinuatus. Not the identification key (SCHILTHUIZEN &VALLENDUUK, 1998) but the species-specific shape of the seventh tergite (i.e. withsemicircular notch = T. sinuatus) was conclusive.P a g e | 69