Necrophagous beetles of genus Thanatophilus are well recognized as a group of beetles with a high potential utility in forensic entomology. They can be used to estimate postmortem interval (PMI) or validate the value for other groups of insects commonly encountered on human remains, like blowflies (Calliphoridae). However, reliable tools for instar and species identification of their larvae are needed as such information is crucial for allowing accurate PMI estimate. One of the most common species of the genus Thanatophilus in Europe is Thanatophilus sinuatus. This species occurs frequently on human remains and its larvae feed on decaying tissues throughout their development. Therefore, the larvae could become useful bioindicators for forensic entomology, although their current description does not allow reliable instar or species identification. Our goal was to provide morphological characters for species and instar identification of all larval stages of T. sinuatus. The larvae were obtained from laboratory rearing under controlled conditions (20 °C and 16:8 h of light/dark period). Qualitative and quantitative morphological instar and species-specific characters are described and illustrated. Additionally, we report observations of biological and developmental lengths for all stages of the species. We also compared these morphological characters with recent description of T. rugosus and provided an identification key of these two similar and often co-occurring species. We noticed that some characters for instar identification were shared between T. sinuatus and T. rugosus and were confirmed by comparison with larvae of T. dentigerus that they can be applied to other species of the genus.
- Keywords
- Forensic entomology, Larval instar identification, Morphology, Thanatophilus sinuatus,
- MeSH
- Coleoptera classification growth & development MeSH
- Forensic Entomology * MeSH
- Evaluation Studies as Topic MeSH
- Pupa classification growth & development MeSH
- Larva classification growth & development MeSH
- Microscopy, Electron, Scanning MeSH
- Optical Imaging MeSH
- Feeding Behavior MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Determination of insect species and their instars, occurring on human remains, is important information that allows us to use insects for estimation of postmortem interval and detect possible manipulation with the body. However, larvae of many common species can be identified only by molecular methods, which is not always possible. The instar determination is even more challenging, and qualitative characters that would allow a more precise identification are mostly unknown. Thanatophilus rugosus (Linnaeus, 1758) is a common necrophagous beetle in the whole Palaearctic region from Europe to Japan. The species is often encountered on corpses of large vertebrates including humans, and its potential to become a useful bioindicator for forensic entomology is therefore high. Adults can be easily distinguished from other species; however, larvae were never thoroughly described to allow species and instar identification. The aim of this study was to provide reliable morphological characters that would allow species and instar identification of T. rugosus larvae. The material for morphological study was obtained from rearing under controlled conditions (20 °C and 12:12 h of light/dark period), and specimens that were not studied morphologically were allowed to complete their development. Quantitative and qualitative morphological characters for instar and species identification are described and illustrated. Additionally, we report observations of biology and developmental length for all stages of the species.
- Keywords
- Forensic entomology, Larval instar identification, Morphology, Thanatophilus rugosus,
- MeSH
- Coleoptera growth & development MeSH
- Larva growth & development MeSH
- Microscopy, Electron, Scanning MeSH
- Optical Imaging MeSH
- Forensic Sciences MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
