Meet the mosquito expert helping Michigan fight insect viruses

Edward Walker knew he found the right profession the first time he successfully got cockroaches to mate inside a jumbo pretzel jar.

As an undergraduate student at Ohio University in the late 1970s, Walker worked in his biology professor’s lab as an aide and was tasked with producing enough female cockroaches for 120 biology students to dissect and study.

Walker went to work placing water containers and small bits of dog food in pretzel jars to help the cockroaches get acclimated to their new home and comfortable enough to start reproducing.

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“I liked doing the insect husbandry – I was good at it,” recalled Walker, 66, an entomology professor at Michigan State University. “I could grow the insects and make sure they were in good shape.”

Acting as Cupid for cockroaches was Walker’s first taste of the wide world of entomology. From there, Walker has focused his nearly 40-year career as a medical entomologist and professor researching the impact of insects on people’s lives in different corners of the world. 

In his career, he’s helped a hospital and a Ford plant mitigate swarms of flies that were impacting the businesses’ bottom line, and assisted in identifying how long bugs have lived on corpses in murder investigations. 

“The kinds of insects that have colonized the decomposing body can be used as forensic, not just information, but actual evidence in court to try to present information about how long the body might have been in place at a location and things like that,” Walker said. 

Most of his time, though, is spent studying what in the summer seems like Michigan’s state bird – the mosquito.

The main focus of his current studies are focused on how mosquitoes transmit diseases to humans and developing ways for tracking how those diseases spread from one source to another. In Africa, his work is focused on ‘interrogating’ mosquitoes, or developing a roadmap of what kinds of people malaria-carrying mosquitoes like to bite over others. In his work based in Michigan, Walker works with the state health department to track disease-carrying mosquitoes flying around Michigan to help inform people if any part of Michigan is endemic to diseases like Eastern Equine Encephalitis (EEE), or the West Nile Virus. 

Walker collects mosquitoes from different areas of the state to do blood tests to see what animals they’ve been biting and deliver mosquitoes to state labs to test for EEE. The research in Michigan is key to understanding how EEE is transmitted throughout the summer. 

On a recent excursion near Dexter, Walker and his team of students laid down black tree planters on their side next to a bog. He explained that the tree planters mimic the natural environment of the mosquitoes they were trying to collect.

The students used a battery-powered aspirator – or a hairdryer on steroids as Walker described it – to suck mosquitoes out of the box into a small mesh cup where they could be transported back to the lab for study. The goal is to track EEE in the Michigan mosquito population weekly throughout the summer to see if the infection rate grows as mosquitoes reproduce. 

“There are birds here that will be infected with the virus and the mosquitoes and birds pass it back and forth through the whole summer,” Walker said. “And the risk is, if the infection rate of the virus goes up in the mosquito and bird populations, that would elevate the risk for people living around here.”

The corralled mosquitoes buzzed around angrily after getting sucked up with the insect vacuum, but Walker and his students were still able to identify the specific mosquito species they’re studying and even how many male and female mosquitoes they had. The species, Culiseta Melanura, is an EEE carrier and can be identified by the hair on its body and longer feeding tube. 

“The mosquito with the long nose and the armpit hairs – that's the one we're looking for,” the professor said.

More than 40 years after helping cockroaches mate, Walker still feels at home and gets a little rush every time he goes out into the field to collect mosquitoes. For him, being able to spend time in nature makes the job feel like a privilege. 

“This is the real world right here,” Walker said with an ear-to-ear grin while collecting mosquitoes. “There's no screen between me and it, that's what I like.”

Walker describes his relationship with nature as an intrinsic love that drives his work. When he’s not out collecting insects or looking at them through a microscope, he tries to spend as much time as possible bird-watching or going to MSU’s public gardens. 

“I think it's really important, particularly in this … age (when it seems as if you) have to have a screen open in front of you or you have to have your cell phone in front of your face, to encourage people to get away from that and just look at nature and really appreciate it for the living things that we see.”

His summer staff this year consists of three undergraduate lab aides to help with mosquito collecting. On the long car ride to collection sites, he talked with them about what careers they wanted to pursue and gave them names of people to reach out to. In the field, he demonstrated how to use a portable vacuum to suck up mosquitoes while talking about the distinction of male and female mosquitoes. The flow of information that Walker only stopped when he turned his head to identify what bird was chirping or to point out patches of poison ivy poking up from the ground. 

“I want to really extend our university experience way beyond the classroom experience to something that's much more tangible,” Walker said.

Walker received his doctorate in entomology from the University of Massachusetts in 1982 and landed at Michigan State in 1986. Thirty-six years later, Walker still conducts experiments in his lab in MSU’s Natural Sciences building to understand how insects – particularly disease-carrying ones like mosquitoes and ticks – impact people’s day-to-day lives. 

“I consider myself to be extremely privileged,” Walker said. “I get to do things that I think are meaningful for people's lives who are residents of Michigan all the way out to people who live in villages somewhere in Africa.”