Sarah Langer, originally from Cavendish Township, Ontario, completed a Master of Science in the Environmental and Life Sciences Program and a Bachelor of Science in Forensic Science at Trent University.

Her research worked to enhance forensic entomology through morphological and ecological research with blow flies collected from across Canada.

In front of entomology collection boxes

Sarah worked with the Ontario Provincial Police (OPP) and the Royal Canadian Mountain Police (RCMP) to answer the main question: whether blow fly species vary between urban and rural habitats.

Blow fly species in Canada are particularly interesting because they help OPP and RCMP officers predict “time of death” in some crime investigations. 

As Sarah worked with the collected specimens, she found an additional morphological feature to aid in differentiating two similar blow fly species.


A large component of her research was collaborating with OPP and RCMP officers across the country to obtain samples!

From these samples, the thousands of collected blow flies were removed and the species were identified.

ArcGIS, an online mapping tool, was used to map landcover types and compare species diversity between collection sites.

Box of pinned blow flies

From this work, Sarah was able to generate a list of blowfly species found across Canada and at each collection site.

Her research found that blow flies in urban areas were more similar to those in other urban areas across Canada than they were to their surrounding rural areas.

Netting blow flies at the Trent Bioblitz

Sarah’s research shows that urban centers have a direct impact on the species distribution of blow flies which can be used to predict which species are available for colonization and what we would expect to obtain from the crime scene.

It also suggests that urban areas have less species overall.

The direct collaboration with the OPP and RCMP identification officers was important, as the collaboration between science and those who use it is an asset in forensics.

Sarah says,

“The Environmental and Life Sciences program is very supportive with program coordination staff Linda Cardwell and Mary-Lynn Scriver truly caring about student success. As my project had a forensic focus, staff in the forensic program with real world experience in the field were also integral to my project’s success, such as retired Staff Sargent and current professor Mike Illes who facilitated our collaboration with officers across the country. Through my MSc I was also encouraged to participate in hands-on experiences that broadened my resume and skills, including an opportunity to assist OPP training with one of my supervisors, Dave Beresford. Trent’s mix of faculty available to the ENLS program creates unique opportunities to explore research you’re most passionate about. I’m truly lucky to have studied forensic entomology through this program.”

Thank you so much for sharing your research with us, Sarah! Keep up the good work.