Detection of fly artifacts from four species of necrophagous flies on household materials using immunoassays
An immunoassay was previously developed as a technique to improve methods for detection and analysis of fly artifacts found at crime scenes. The dot blot assay utilized a polyclonal antiserum (anti-md3) based on a unique digestive cathepsin D found in cyclorrhaphous Diptera. In this study, artifacts produced by adults of Calliphora vicina, Cynomya cadaverina, Sarcophaga bullata, and Protophormia terraenovae were examined using the immunoassay to determine if insect-derived stains could be distinguished from a range of human body fluid stains. A lift technique was developed which permitted transfer of fly artifacts from test materials to filter paper for dot blot analyses. All species readily deposited artifacts on all test household materials regardless of diet consumed. Despite differences in texture and porosity of the household materials, artifacts of all species transferred to the filter paper. With all fly species, anti-md3 serum bound to artifacts produced after feeding on semen, blood, feces, urine, and saliva. By contrast, anti-md3 serum did not react with any of the human fluids tested, nor with any of the lifts from household materials not exposed to flies. There was no evidence of false positives with any of the fly species tested, regardless of diet consumed. There was also no indication of false negatives with any of the dot blot assays. These observations suggest that immunoassays using anti-md3 serum performed on a simple lift of suspected fly artifacts can be used effectively as a confirmatory assay to distinguish fly regurgitate and fecal stains from human body fluids.
KeywordsInsect stains Digestive artifacts Bloodstains Immunodetection Forensic entomology
The authors thank Brian Martin from Carpets by Martin (Shrewsbury, Pennsylvania, USA) for generously providing some of the carpet samples used in this study. This project was supported by Award No. 2016-DN-BX-0181, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect those of the Department of Justice.
Compliance with ethical standards
This research does not contain studies involving human or vertebrate animal subjects.
Conflict of interest
The authors declare that they have no conflict of interests.
- 9.Parker MA, Benecke M, Byrd JH, Hawkes R, Brown R (2010) Entomological alteration of bloodstain evidence. In: Byrd JH, Castner JL (eds) Forensic entomology: the utility of using arthropods in legal investigations, 2nd edn. CRC Press, Boca Raton, pp 539–580Google Scholar
- 10.Smith KGV (1986) A manual of forensic entomology. London and Cornell University Press, LondonGoogle Scholar
- 12.Rivers DB, Geiman T (2017) Insect artifacts are more than just altered bloodstains. Insects: Adv Forensic Entomol. https://doi.org/10.3390/insects8020037
- 14.Peters W (2003) Ernährung und Verdauung. In: Dettner K, Peters W (eds) Lehrbuch der Entomologie Spektrum. Verlag, Munich, pp 91–126Google Scholar
- 15.Rivers DB, Cavanagh G, Greisman V, McGregor A, Brogan R, Schoeffield A (2019) Immunoassay detection of fly artifacts produced by several species of necrophagous flies following feeding on human blood. Forensic Sci Int: Synergy. https://doi.org/10.1016/j.fsisyn.2018.11.001
- 16.Bevel T, Gardner R (2008) Bloodstain pattern analysis: with an introduction to crime scene reconstruction, 3rd edn. CRC Press, Boca RatonGoogle Scholar
- 23.Durdle A, Mitchell RJ, van Oorschot RAH (2011) The change in human DNA content over time in the artefacts of the blowfly Lucilia cuprina (Meigen) (Diptera: Calliphoridae). Forensic Sci Int 3:e289–e290Google Scholar
- 25.Pelletti G, Mazzotti MC, Fais P, Martini D, Ingra L, Amadasi A, Palazzo C, Falconi M, Pelotti S (2019) Scanning electron microscopy in the identification of fly artifacts. Int J Legal Med. https://doi.org/10.1007/s00414-019-02090-5
- 28.Marshall SA, Whitworth T, Roscoe L. (2011) Blow flies (Diptera; Calliphoridae) of eastern Canada with a key to Calliphoridae subfamilies and genera of eastern North America, and a key to the eastern Canadian species of Calliphorinae, Luciliinae and Chrysomyiinae. Can J Arthr Ident No. 11: doi: https://doi.org/10.3752/cjai.2011.11
- 31.Oldfield C, Morgan RM, Miles HF, French JC (2017) The efficacy of luminol in detecting bloodstains that have been washed with sodium percarbonate and exposed to environmental conditions. Aust J Forensic Sci. https://doi.org/10.1080/00450618.2016.1264478
- 33.Fujikawa A, Barksdale L, Carter DO (2009) Calliphora vicina (Diptera: Calliphoridae) and their ability to alter the morphology and presumptive chemistry of bloodstain patterns. J Forensic Ident 59:502–512Google Scholar
- 40.Leyria J, Fruttero LL, Ligabue-Braun R, Defferrari MS, Arrese EL, Soulages JL, Settembrini BP, Carlini CR, Canavoso LE (2018) DmCatD, a cathepsin D-like peptidase of the hematophagous insect Dipetalogaster maxima (Hemiptera: Reduviidae): purification, bioinformatics analyses and the significance of its interaction with lipophorin in the internalization by developing oocytes. J Insect Physiol 105:28–39CrossRefGoogle Scholar