Rampa Rattanarithikul, at her museum in northern Thailand, has helped identify more than 420 mosquito species and discover two dozen more.

By JENNIFER PINKOWSKI

CHIANG MAI, Thailand - Rampa Rattanarithikul is sitting on a stool in the Museum of World Insects and Natural Wonders, which she founded with her husband in 1999. Behind her hangs some museum merchandise - T-shirts printed with a mosquito graphic - and on the walls are vaguely psychedelic paintings of giant mosquitoes posing before blood-orange sunsets.
Suddenly, she leans down with a longpracticed motion and swats at her ankle. “Mosquitoes are my enemy,” she says with a weary laugh.
Dr. Rattanarithikul, 69, has devoted 50 years to the study of mosquitoes, first as an entry-level technician, then as a trained taxonomist and finally as a medical entomologist for the Armed Forces Research Institute of Medical Sciences, or Afrims. It is a joint American-Thai medical project under the auspices of the Walter Reed Army Institute of Research and the Royal Thai Army.
She has collected hundreds of thousands of specimens . She has classified, dissected, analyzed and mounted the limp little bodies onto slides. Most were shipped to the Walter Reed Biosystematics Unit at the Smithsonian Institution in Washington, where they constitute perhaps half of the collection of 1.5 million mosquitoes, the largest in the world. She also maintains a large collection at the Afrims museum in Bangkok.
This painstaking, classical taxonomy has helped identify more than 420 mosquito species and discover two dozen more.
“Her work has been a major contribution,” said Ralph E. Harbach, an American entomologist at the Natural History Museum in London and a former Afrims officer who has collaborated with Dr. Rattanarithikul since the early 1980s. “Without it we would be 40 years behind in that region.”
Thailand is the hub for understanding the nature of mosquitoes in Southeast Asia, Dr. Harbach said. It is home to about 14 percent of the world’s 3,000 mosquito species. Researchers in neighboring countries where mosquitoes cause enormous public health problems can use Dr. Rattanarithikul’s work to help distinguish the hundreds of harmless, if annoying, mosquito species from the dangerous, disease-carrying “vector” species. In Thailand, of the 450 identified species, 10 are vector species.
Though she retired from Afrims in 1997, Dr. Rattanarithikul has since rejoined the institution and continues to research vector species. In Thailand, these mostly fall into three genuses: Anopheles, Aedes and Culex. When mosquitoes bite humans, they can infect us with parasites or viruses; bites can transmit diseases like malaria, dengue fever and Japanese encephalitis.
Today, geneticists and molecular scientists can test mosquitoes for infections with unerring accuracy. But only vector species need to be tested. That is where Dr. Rattanarithikul’s taxonomical expertise comes in. “I trust my eyes and the microscope,” she said.
The culmination of her life’s work is the six-volume Illustrated Keys to the Mosquitoes of Thailand, published by The Southeast Asian Journal of Tropical Medicine and Public Health.
“Anyone can use my keys,” she said. That is important in a region beset by mosquito-borne diseases (though not as devastated as sub-Saharan Africa, where Anopheles gambiae spreads malaria). Of its neighbors, Thailand has had the most success in lowering infection rates, with a national effort dating to the 1960s.
It is the pressing nature of this research that keeps Dr. Rattanarithikul working. “I want to publish these keys, but then I want to give up mosquitoes,” she said. “I would like to work with our collection here.”