UF master’s student joins Yale research team in first Everglades mosquito study

Florida summers are notoriously hot, humid and buggy.

So Mary Leigh Morris’ summer, spent in Everglades National Park, one of Florida’s muggiest spots, surrounded by one of our peskiest insects, the mosquito, might seem less than ideal. But Morris, a One Health master’s degree student in the College of Public Health and Health Professions’ department of environmental and global health, had the unique opportunity to join a Yale University team in the first systematic study of the Everglades’ mosquitoes.

Mary Leigh Morris and fellow researchers collected mosquitoes in various habitats within Everglades National Park, such as this cypress dome swamp.
Mary Leigh Morris and fellow researchers collected mosquitoes in various habitats within Everglades National Park, such as this cypress dome swamp.

Led by Durland Fish, Ph.D., a Yale professor of epidemiology (microbial diseases) and of forestry and environmental studies, the research team sought to determine what mosquito species live in the Everglades, which habitats within the park certain species prefer, and what mosquito-borne viruses are present in resident insects.

In a three-month period the team collected 90,000 mosquitoes in five Everglades habitats: hardwood hammock, cypress, sawgrass prairie, mangrove and pineland. They identified 30 different species of mosquitoes.

“We found there is a great diversity in Everglades mosquitoes and we started to see some trends in what species preferred what habitats,” said Morris, who participated in the project as part of her degree program’s fieldwork requirement.

The researchers sent mosquito samples to a University of Texas Medical Branch laboratory for virus testing and analysis is underway.

The team hopes that this first study of the Everglades’ mosquitoes leads to sustained studies that include more collection sites within the park and year-round testing to see how mosquito populations change with the seasons. Further study may also clear up mysteries such as where the mosquito Culex cedecei prefers to lay its eggs. The species is abundant within the park and is a known human disease carrier.

Morris says the Everglades mosquito project was a great example of the One Health approach at work. One Health seeks to involve human, animal and environmental health expertise in public health problem solving. Such collaboration is required in addressing complex issues such as human to animal disease transmission and food safety.

Morris studies a reference mosquito at the Florida Keys Mosquito Control District where the team trained.
Morris studies a reference mosquito at the Florida Keys Mosquito Control District where the team trained.

“My first field experience taught me to think on my feet and plan for the unknown,” Morris said. “It taught me how to work with people from a lot of different organizations. You can’t do a study like this without help from many groups. I’m thankful so many people were willing to take me on and it’s nice to know people are embracing the idea of One Health.”

And surprisingly, Morris, a Mississippi native, says summer in the Everglades isn’t too bad. To combat bug bites, she sprayed her clothes with an insecticide containing permethrin, a long-lasting chemical that stays on clothing through washings. The team placed and collected mosquito traps in the evenings and mornings when the temperatures were cooler. Walks to the collection sites gave Morris an opportunity to view lots of wildlife and beautiful scenery.

“The sunsets in the Everglades go on forever,” she said.