Northern State University team spent third summer trapping mosquitoes

Dr. Jon Mitchell and his team of Northern State University students trapped mosquitoes around Brown County this summer – and that meant finding the spots these pests prefer.

“You’ve got to think like a mosquito,” said Mitchell, assistant professor of biology.

Mosquitoes prefer places protected from the wind, but still sunny, with tall grass and moisture. So those are some of the criteria the team sought when setting up their traps.

This was the third year NSU has participated in South Dakota’s mosquito surveillance project, aimed at identifying and testing mosquitoes that can carry West Nile virus. Each year, Northern’s efforts have grown, with more traps and more students involved

Ten students were involved this year: Annika Van Oosbree, Courtney Henschel, Paige Sommers, Alison Byrd, Tessa Durnin, Larissa Kempf, Miranda Ristau, Ian Muirhead, Sam Bahr and April Moeller. The group was led by Mitchell and Dr. Alyssa Anderson, assistant professor of biology.

The group is making an impact on a disease that is a big concern for the area. Brown County historically has one of the highest rates of West Nile virus in the country.

The effort has been funded through awards totaling $109,973 from the South Dakota Department of Health (DOH), with funds from the Centers for Disease Control and Prevention (CDC). The NSU team was specifically looking for the mosquito species Culex tarsalis, considered the most likely carriers of West Nile virus.

The traps included a tank of carbon dioxide, which gets released and lures the mosquitoes, which then get sucked into the trap by a fan. Mitchell and the students collected the mosquitoes, sorted them by genus and species, and counted them. The Culex tarsalis is easy to identify because of its white knees and white patch on its proboscis, Mitchell said. They sent all the Culex tarsalis they found to the DOH in Pierre every week to be tested for West Nile virus.

New this year, the DOH and CDC were interested in understanding mosquito resistance to insecticide. So the NSU group studied the effect of the insecticide Permethrin on mosquitoes at different levels. The resistance study will provide valuable data to the DOH for pest management strategies.

Along with benefiting entities across the state, Mitchell said, this work brings funding to the university, fits with its vision of becoming the state’s Center for Environmental Studies, and fits in with his own ongoing research. Mitchell received a South Dakota Board of Regents grant a couple of years ago to study the effectiveness of natural products in the control of mosquitoes.

It’s also beneficial for the students involved, who get credit for the paid internship and gain great field experience to include on their resumes. They also get to present their work at various venues, including the state’s mosquito control conference in Aberdeen in September and possibly the national Entomological Society of America annual meeting in Minneapolis in November. Students also showcased the mosquito trapping to schoolchildren at the Northern Plains Water Festival at the Barnett Center at the end of September.

Students are working in the field and the lab, Mitchell said, and they get to see the importance of their work to the community.

“The bottom line is we’re giving students hands-on, real world experience both in the classroom and during the summer.”