Inside Iowa State

Jan. 27, 2006

Marveling at mosquitoes

by Barbara McBreen, Ag Communications

Seeing beauty in the eyes of a mosquito set Lyric Bartholomay on a path of passion. That path has taken her to Egypt to scoop mosquito larvae out of the Nile River and into labs to extract blood from mosquitoes under a microscope.

"I took a general entomology course at Colorado State and it was just awesome, so I decided to major in entomology," said Bartholomay, assistant professor of entomology. "I also was interested in infectious diseases and I found I could combine the best of both worlds in medical entomology."

She arrived at Iowa State at the height of West Nile virus season last summer and took over responsibility for ISU's Medical Entomology Lab. The lab is the central location for monitoring Iowa's mosquitoes and the diseases they transfer to humans.

Bartholomay oversees the statewide mosquito surveillance program that was established by Wayne Rowley, entomology professor emeritus, more than 35 years ago.

"We trap mosquitoes at 13 locations across Iowa during the summer. Mosquitoes are trapped nightly and mailed to the lab every week," Bartholomay said. "The trapped mosquitoes give us an idea of how the populations are fluctuating over the summer."

The lab monitors several insect-borne diseases in collaboration with the Iowa Department of Health and the University of Iowa. Mosquitoes are monitored for West Nile virus, Western Equine encephalitis virus, Saint Louis encephalitis virus and LaCrosse virus. In 2005, there were 37 reported cases of West Nile and two deaths in Iowa.

"We send reports to state health agencies and let them know how many nuisance or vector species are out there and if they're carrying West Nile virus. This gives them an idea of when to implement mosquito control measures, or to warn the public of West Nile virus activity," Bartholomay said.

During the winter, research on West Nile continues. Mosquitoes are kept in controlled environments in two walk-in incubators at 80 degrees and 80 percent humidity. The walk-ins are lined with racks of larvae swimming in white, enamel cake pans on one side and adult mosquitoes buzzing in cages on the opposite.

"The vast majority of mosquitoes can't transmit pathogens," Bartholomay said. "If we can understand why some mosquitoes don't transmit diseases, we may be able to develop a strategy for controlling disease transmission."

Mosquitoes get West Nile virus from feeding on infected birds, but researchers are looking at how -- or if -- other animals may transmit the disease. As soon as she arrived, Bartholomay began working with Rowley and Ken Platt, professor of veterinary microbiology and preventive medicine, who are conducting research on mammals and their role in the transmission of West Nile virus in Iowa.

Bartholomay also teaches a class that introduces undergraduate students to disease-carrying insects throughout the world, from the sand flies infesting Baghdad to mosquito swarms in Africa.

"You may have heard about the disease carried by sand flies, which causes the 'Baghdad boil,' and plagues soldiers stationed in Iraq and Afghanistan," Bartholomay writes in her class syllabus.

She hopes students in her classes take away the same enthusiasm she has for discovering and understanding the relationship between diseases and insects.

"The interaction between a pathogen and an insect is fascinating and extremely complex," Bartholomay said.

Bartholomay still communicates with students who took her parasitology course at the University of Wisconsin, Madison, where she earned her doctoral degree (2004). One student delayed her entrance into medical school to work for a year in an orphanage in Central America.

"She e-mailed me recently and wanted me to know how important my course was for her understanding of the potential diseases she could contract in her travels. It's rewarding to think that I may have had even a small part in her inspiration to help people living in developing countries," Bartholomay said. "She's an incredible soul."

A shadowbox sitting on Bartholomay's windowsill houses two giant mosquitoes measuring six-inches long. The models are teaching aids for students. Picking up the box, she points out the delicate and beautiful elements of the mosquito's anatomy.

"I'm fascinated by the evolution and diversity of insects. It's wonderful to be an entomologist, admiring these tiny creatures that are so well-evolved, have innumerable life strategies and inhabit an amazing diversity of environments," Bartholomay said.

"They also are quite beautiful. Even the species most important in transmission of West Nile Virus has beautiful, iridescent green eyes."

"It's wonderful to be an entomologist, admiring these tiny creatures that are so well-evolved, have innumerable life strategies and inhabit an amazing diversity of environments."

Lyric Bartholomay