Aug. 13, 2012, 12:35 p.m.
Those pesky mosquitoes snacking on your arms and legs aren’t only out for blood.
Like most other creatures, they have a favorite food. In their case, it’s sweet, succulent flower nectar.
Mosquitoes don’t pollinate flowers as other insects do. After sniffing out a floral fragrance, they track down the plant and steal its nectar for energy.
That weakness for nectar, however, could be the blood-sucker’s kryptonite.
Using flower scents created in a lab, a team of researchers at Ohio State University plans to lure mosquitoes into traps.
The objective: Kill the pests that carry life-threatening diseases, including West Nile Virus and malaria.
“Think of the perfume industry. It’s the same approach, but we’re using it to trap mosquitoes for public-health purposes,” said Philip E. Otienoburu, an OSU entomologist.
Using a grant from the National Institutes of Health, the research team began working on its synthetic-lure study in 2006 and published its results in June in the Journal of Chemical Ecology.
The first step was building a machine, called an olfactometer, to detect and measure odor. That started in 2006. The team began analyzing plant chemicals in 2008 and got to the tests two years later.
The experiment was simple: Give a mosquito two options and see which one it chooses.
Researchers released common house mosquitoes, Culex pipiens, into a space that contained two jars. One jar was empty, and the other contained an artificial milkweed flower scent that the researchers created by extracting and studying chemicals from the actual plant.
“It’s kind of like putting together a recipe,” said Larry Phelan, an OSU professor who has studied insect chemical ecology for more than 30 years. “You get very different flowers based on how much of each component you put in.”
In the lab, mosquitoes routinely swarmed to the milkweed scent Phelan created. Now, the hope is that the insects will swarm to the synthetic blend in backyards, too.
The problem with most traps is that they rely on carbon dioxide and other chemicals to imitate potential blood meals, Phelan said. (When we say blood meals, we mean humans and animals.) But because only female mosquitoes bite and they sometimes forgo blood for flowers, the traps’ results are limited.
However, a trap that uses synthetic floral scents could attract females and males, which hatch before females.
Finding males in traps “could potentially give you an early-warning system of when females are going to be active,” Phelan said. “We need more ways to monitor insect populations, whether for agriculture, household pests or disease-transmitting pests.”
For local public-health officials, the traps would offer a creative way to combat mosquito-borne diseases.
Columbus Public Health tracks mosquito populations and sprays neighborhoods based on what it finds in traps. The department has confirmed West Nile Virus in central Ohio mosquitoes every year since 2002, said Luke Jacobs, section chief with the Division of Environmental Health.
There were 21 human cases of the virus in Ohio last year, one fatal, according to the Centers for Disease Control and Prevention.
“This study could affect the market for attractants, and we’re never opposed to finding new ways to attract mosquitoes,” Jacobs said.
The research team plans to take its study into the field soon, but the venture won’t be without its challenges, Otienoburu said. For example, synthetic scents might not be as effective as the real thing outside the lab.
“You’re pretty much competing with God,” Otienoburu said.
But that won’t keep the researchers from trying.
They hope someday to expand the study and identify scents that would attract a host of mosquitoes around the world, particularly those that transmit malaria in African countries, where a child dies every minute from the disease, according to the World Health Organization.
To Babak Ebrahimi, a graduate student in entomology at Ohio State, the ultimate goal is saving lives.
That’s what makes the years of researching, testing and writing worthwhile, whether he’s staking out a humid milkweed greenhouse or feeding a swarm of his lab-raised mosquitoes with his arm.
“This is nothing,” Ebrahimi said as he slid his arm into a container with about 50 insects. “Think of the millions of people who die each year from malaria. I’m doing this for them."