DNA Barcoding Identifies Unknown Females and Larvae of Fannia R.-D. (Diptera: Fanniidae) from Carrion Succession Experiment and Case Report

Abstract

Application of available keys to European Fanniidae did not facilitate unequivocal species identification for third instar larvae and females of Fannia Robineau-Desvoidy, 1830 collected during a study of arthropod succession on pig carrion. To link these samples to known species, we took the advantage of molecular identification methods and compared newly obtained cytochrome oxidase subunit I (COI) barcode sequences against sequences deposited in reference databases. As an outcome of the results obtained, we describe for the first time a third instar larva of Fannia nigra Malloch, 1910 and Fannia pallitibia (Rondani, 1866) and a female of Fannia collini d’Assis-Fonseca, 1966. We provide combinations of characters allowing for discrimination of described insects from other Fanniidae. We provide an update for the key by Rozkošný et al. 1997, which allows differentiation between females of F. collini and other species of Fanniidae. Additionally, we provide a case of a human cadaver discovered in Southern Poland and insect fauna associated with it as the first report of F. nigra larvae developing on a human body.

Necrophagous insect species succession on decomposed pig carcasses in North Dakota, USA

“…Insect specimens can be identified using classical taxonomic identification keys; however, numerous species in the larval stage are difficult to identify with dichotomous keys or are unknown to science. Hence, insect species can be confirmed or identified via DNA Barcoding based on the cytochrome c oxidase I (COI) gene (Grzywacz et al 2021). These molecular-based approaches have been developed to help and improve species identification in difficult circumstances, such as new species, unknown larval identifications, and even damaged specimens (Grzywacz et al 2021, Tembe et al 2021, Yan et al 2021).…”

“…Hence, insect species can be confirmed or identified via DNA Barcoding based on the cytochrome c oxidase I (COI) gene (Grzywacz et al 2021). These molecular-based approaches have been developed to help and improve species identification in difficult circumstances, such as new species, unknown larval identifications, and even damaged specimens (Grzywacz et al 2021, Tembe et al 2021, Yan et al 2021). The identification of necrophagous insect species also depends on the proper sampling and preservation techniques of both adult and immature specimens (Haskell and Williams 2008).…”

“…Sometimes, sampling of specimens can be performed at the crime scene or only during autopsy (Lutz et al 2021). The specimen preservation can be performed in 70% ethanol for taxonomic analysis (Marquina et al 2021) or in 96% ethanol for molecular analysis (Grzywacz et al 2021), while live specimens are collected and transferred to a meat substrate and maintained at a constant temperature and humidity until adults emerge (Bambaradeniya et al 2023).…”

Looking Back to Move Forward: How Review Articles Could Boost Forensic Entomology

“…Molecular biology, and especially DNA-based methods, are thus widely investigated. In this Special Issue, Gzywacz et al [ 11 ] provide a good example of the value of molecular methods when morphological identification is not possible. However, while powerful and increasingly accessible, these methods remain more expensive and time-consuming than traditional morphological identification.…”