USM Assistant Professor Preparing for Large-Scale Mosquito Research in Puerto Rico

Dr. Donald Yee, assistant professor of biological sciences at The University of Southern Mississippi, and two of his graduate assistants are preparing to embark upon a research project in Puerto Rico that could yield transformative benefits to that U.S. territory and its 3.3 million inhabitants.

Yee, along with graduate students Catherine Dean and Limarie Reyes (a Puerto Rican native), will travel to Puerto Rico in early August to collect samples of local mosquitoes and mosquito larva in more than 20 locations across the island. He expects the research project to take approximately three weeks.

In the last three years, Puerto Rico has experienced massive outbreaks of two newly discovered mosquito-borne diseases, causing devastating effects for Puerto Rican citizens. Mosquito-borne diseases like Zika, for example, can have a wide range of negative effects on pregnancies, causing higher rates of miscarriages and birth defects in developing fetuses.

“Once we are done, we'll have a better idea of what species are on the island and where they can be found,” said Yee, who previously lived in Puerto Rico for a year. “This sort of survey has not been conducted in a systematic way since the 1930s. We know there may be some important disease carrying mosquito species on the island, but we have insufficient knowledge about their location or distribution.”

The identification of the mosquito species on the island will be the first step in controlling the mosquito populations and reducing the diseases that they spread to Puerto Rican citizens and tourists. Different species of mosquitoes are capable of carrying different parasites and diseases, and different varieties of mosquito larva are found in different habitats.

Some varieties will incubate in open water and can be controlled with larvicides, while others develop in small bodies of water that collect in abandoned tires and other refuse which must be disposed of or kept empty of water. By identifying which species are present on the island and where they live, the mosquito populations can be controlled more effectively.

Yee has visited Puerto Rico more than a dozen times, including three trips thus far in 2018. He points out that on a broader scale the upcoming project will provide a better understanding of mosquitoes in the Caribbean, an area in which significant gaps in knowledge and understanding of the insect exists.

“This is important as there are many tropical diseases that often exhibit outbreaks in these warmer areas, and we often see significant travel to those areas from the mainland United States,” he said. “Thus, when there is a Zika or dengue outbreak in Puerto Rico, because of tourism this has the potential to spread elsewhere, including to places like Mississippi.”

Yee joined the USM faculty in 2008. His primary area of expertise is the community and population ecology of aquatic insects. He has spent more than a dozen years researching mosquito ecology, and the results of his research have been published in numerous journals, including the Journal of Medical Entomology and Annals of the Entomological Society of America.

Closer to home, the sweltering summer months in South Mississippi offer prime breeding conditions for various mosquito species. Last year there were 63 cases of West Nile Virus reported in Mississippi, and two of those resulted in deaths. Yee says it is practically impossible to predict how prevalent mosquito-related diseases will be before this year's end.

“Warm winters and wet springs are often things to look at when anticipating mosquito populations,” said Yee. “I don't have a sense of how bad things have been so far, although I knew were rather dry earlier this spring which led to lower populations.”