All insects matter: a review of 160 entomology cases from 1993 to 2007 in Switzerland-part I (Diptera)

Abstract

Necrophagous Diptera are the most important group of insects used for the purposes of forensic entomology. While the most utilized fly family in this context is the family Calliphoridae, there are several other families that can be of great importance during real-case investigations. This article analyzes the necrophagous flies of all families recorded from 160 real cases in Switzerland between 1993 and 2007. A total of 56 species belonging to 16 families was identified with Calliphoridae being the most dominant family (90.63% of all cases), followed by Muscidae (26.25%), Sarcophagidae (19.38%), Phoridae (14.38%), and Fanniidae (12.50%). For specimens that were difficult to identify morphologically, a new PCR primer has been specifically designed for the amplification of a short, informative COI barcode in degraded museum samples of forensically important Diptera taxa. The richest family in terms of species was the family Muscidae with 16 species. Fannia fuscula (Fallen) and Fannia monilis (Haliday) were recorded from human cadavers for the first time. The study highlights the importance of different fly families in forensic investigation, enhancing our comprehension of their prevalence and dispersion in real cases in Central Europe. The results pave the way for additional exploration, especially regarding the involvement of less frequently observed species in forensic entomology.

Keywords: checklist; forensic entomology; necrophagous Diptera; real cases; species composition.

Fig. 1.

The map of real-case investigations in and around Lausanne during 1993–2007 (the map of Switzerland cantons downloaded from www.freeworldmaps.net).

Fig. 2.

Boxplots of the distribution of the PMI_min (in days) across different families of Diptera with regards to the location where the body was discovered (indoor/outdoor habitat). The vertical lines within the boxes represent median values; the whiskers represent the values with the 1.5 interquartile ranges; the blue and red dots are outliers. Detailed figures for species of the major families can be found at Supplementary Fig. S1.

Fig. 3.

The occurrence of the collected Diptera families at different seasons. The size of the dot represents the number of records for given taxa and season. Detailed figures for species of the major families can be found at Supplementary Fig. S2.