When students in Jon Oliver’s Field and Laboratory Methods in Public Health Entomology class (PUBH 6184) headed out to the Sarita Wetland on the University of Minnesota’s Saint Paul campus in September, they were hoping to find something that most Minnesotans look to avoid when they go outdoors: mosquitoes. Searching for and collecting the ubiquitous pests serves an educational purpose—the students will later microscopically identify them to see what disease-causing pathogens they are able to transmit—but, Oliver says, it’s also a bonding experience for the class.

“It’s fun because they’re all out there tramping through the woods. Sometimes it can be a little muddy and rough, but the students really embrace it. We do it towards the beginning of the semester and it’s a good starting point and a nice bonding experience,” Oliver said.

It’s an enjoyable outing that underscores a serious—and growing—public health challenge. As climate change and human activity drive insects and animals and their pathogens into unfamiliar regions, the likelihood of zoonotic diseases—those that jump from animals to people—continues to rise. The Centers for Disease Control and Prevention, for example, found the number of reported Lyme disease cases rose significantly between 2017 and 2022.  Oliver says the changes are noticeable all around us. “Deer ticks have really expanded their range,” he said. “Thirty years ago, we didn’t really have deer ticks in the Twin Cities at all. And now basically every forested county in the state has established populations of them.”

Originally developed by Oliver in 2017, the course consists of a mix of lectures, laboratory work, and field trips focused on the ways that pathogens transmitted by insects and arthropods like mosquitoes and ticks are inflicting diseases on humans across the globe. Though it attracts mostly MPH students, the course also draws SPH MS and PhD students, as well as students from the School of Veterinary Medicine.

The mosquito collection is the first of several field trips that anchor the class. Later in the semester, students will venture back out in the field in an attempt to collect ticks, visit the Metropolitan Mosquito Control District, tour EcoLab’s entomology facility to learn about bed bugs, and explore the University of Minnesota Bee Lab,

While the association between ticks and mosquitoes and vector-borne diseases like Lyme and malaria are well-known, Oliver said the Bee Lab provides another perspective on the scope of protecting humans from disease carried by insects and animals. “Most students don’t immediately make the connection between public health and bees,” he said. “But honeybees are actually a vital component to our food supply. If you like fruits and vegetables, you really need honeybees, and bees have a vector-borne disease that’s transmitted by a kind of mite that attaches to the bees.”

Back in the lab, students put bees, ticks, mosquitoes, and other specimens under microscopes in order to familiarize them with the scientific tools and techniques used in vector-borne disease research. Working under high-powered dissecting scopes, the students identify specific types of ticks and mosquitoes, and learn to remove the tiny organs where viruses or parasites may lurk.

Ultimately, Oliver wants students to leave his class not fearful of what’s out there in the woods, but equipped with knowledge they can use to help prevent disease spread. “I try to educate rather than scare,” he said. “Yes, ticks pose a threat to our health. But if you know how to protect yourself and be vigilant, we can still go outside.”