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USM graduate students earn Sigma Xi honor society grants for work with mosquitoes

Fri, 07/19/2019 - 06:59am | By: Kendra Ablaza

Joe Nelsen conducting researchTwo USM graduate students are among the most recent winners of competitive Sigma Xi grant awards. Sigma Xi, also known as The Scientific Research Honor Society, is the international honor society of science and engineering and one of the oldest and largest scientific organizations in the world.

Sigma Xi’s Grants in Aid of Research program awards up to $1,000 to science and engineering students to help them with travel expenses to and from a research site, or with purchasing laboratory equipment necessary to complete a specific research project.

Biological Sciences doctoral student Catherine Dean and second-year graduate student Joe Nelsen both earned $1,000 awards, the highest possible amount. According to Sigma Xi, grant amounts range from $400 to $1,000, with an average award of $600.

Donald Yee, associate professor of ecology and organismal biology, said both Dean and Nelsen participate in his Lab of Aquatic Insect Ecology, where its work centers on urban areas and understanding interactions between humans and mosquitoes.

He said few grants are available to graduate students across a wide range of disciplines like the Sigma Xi grant. Only a few hundred are available nationally each spring and fall. Normally, graduate students have to rely on a faculty member to get research funding.

“It really is a testament to the work of the graduate student to have a solid research project, or proposal, and present that to win this award money,” Yee said. “I help them and so forth, but it is really their project and their grant.”

Dean, who earned the award in spring 2019, researches mosquito stoichiometry, which involves looking at the chemical makeup of a mosquito and its surroundings.

The Memphis native is observing whether levels of phosphorus within mosquitoes change or react to different environments. Because phosphorus has a really important role when building genetic components in the body, Dean said it might have an influence on how well mosquitoes function.

“We’ve found that when there was more nitrogen in the environment, mosquitoes had a lesser chance of transmitting Zika,” Dean said. “There may also be that correlation for other pathogens or elements.”

Dean said her work under the Sigma Xi grant could contribute to her dissertation if her findings are significant. It could even be a building block for more complex efforts, such recording carbon, nitrogen, and phosphorus levels within one mosquito, which is really difficult, Dean said.

Nelsen, who earned the award in spring 2018, is researching how larvicides applied to open-water mosquito populations may benefit mosquitoes instead by killing off some of their predators. His findings could one day lend themselves to an integrated pest management plan that features more environmentally-responsible strategies of controlling mosquitoes of medical importance.

Nelsen, a Fridley, Minnesota native, said his Sigma Xi award money was used throughout last summer to travel back and forth from Hattiesburg to Pass Christian in Harrison County where he worked with Harrison County’s Mosquito Control Department and surveyed roadside ditches, looking at the larvicides commonly applied to ditches, ponds, pools, and wetlands and how they interact with their environments.

Nelsen has also collected samples of common mosquito predators within areas of the state often treated for mosquitoes. He will be examining how those predators react to different doses of larvicides, and if there are any long-term consequences for predators in those habitats.

"Integrated pest management is a pretty interesting area of research," Nelsen said. "Using predaceous insects as biological control of pests is more common in agriculture than medical entomology, which is why I think this project could be important for future control strategies."