Application of DNA-Based Methods in Forensic Entomology

Abstract

Forensic entomology uses insects to help law enforcement determine the cause, location, and time of death of a human corpse as well as to detect poisons, drugs, and physical neglect and abuse. Considered as physical evidence at the crime scene, insect specimens should be processed as any other biological material, following the recommended procedures for quality assurance for collection, preservation, packaging, and transport in order to prevent contamination or destruction of evidence and to guarantee the chain of custody. The occurrence of necrophage species and developmental stages of insects associated with the corpse can support prediction of minimum postmortem interval, maximum postmortem interval, or both. Taxonomic keys, which rely on morphological characteristics, are commonly used for identification of forensically important insects. However, for juvenile stages, adult females, or if a specimen is damaged, morphological identifications can pose a challenge. Consequently, taxonomic misidentification of a specimen can lead to miscalculation of the postmortem interval. In such cases, molecular identification can serve as an alternative approach. This chapter will show how DNA-based methods are used as an auxiliary tool in human forensics, not only to identify forensically important species in any life stage, but also to possibly identify human DNA that may be present in the insects’ guts.