Alteration of Expirated Bloodstain Patterns by Calliphora vicina and Lucilia sericata (Diptera: Calliphoridae) Through Ingestion and Deposition of Artifacts


  • Research funded in part by the University of Nebraska-Lincoln Undergraduate Creative Activities and Research Experiences Program.

  • Presented in part at the 61st Annual Meeting of the American Academy of Forensic Sciences, February 16–21, 2009, in Denver, CO.

Additional information and reprint requests:
David O. Carter, Ph.D.
Department of Entomology
University of Nebraska-Lincoln
202 Entomology Hall
Lincoln, NE 68583-0816


Abstract:  Bloodstain pattern analysis can provide insight into a sequence of events associated with a violent crime. However, bloodstain pattern analysis can be confounded by the feeding activity of blow flies. We conducted two laboratory experiments to investigate the relationships between Lucilia sericata (green bottle fly) and Calliphora vicina (blue bottle fly), expirated bloodstains, and pooled bloodstains on a range of surfaces (linoleum, wallpaper, textured paint). C. vicina and L. sericata changed bloodstain pattern morphology through feeding and defecation. They also deposited artifacts in rooms where blood was not present originally. Chemical presumptive tests (Hemastix®, phenolphthalein, leucocrystal violet, fluorescein) were not able to differentiate between insect artifacts and bloodstains. Thus, C. vicina and L. sericata can confound bloodstain pattern analysis, crime scene investigation, and reconstruction. Crime scene investigators should be aware of these fundamental behaviors, and the effects that blow flies can have on expirated and pooled bloodstain patterns.