Planes can be seen zooming off every so often in the fields just past Wal-Mart, signs that the new Vector Control team is hard at work battling Williston's pesky skeeters.

After the first larva was found on April 17, the crew got to work the very next day.

On Tuesday alone, about four tons of VectoBac (which comes in dry pellets) were dropped in eight separate loads of aerial applications. VectoBac is a larvacide that can kill mosquitoes during the larvae stage of development, containing a naturally occurring bacterium common to soils throughout the world. It is applied to standing water areas where mosquitoes breed, and is safe for children and animals.

"We have been at it for a little over a month now," Vector Control Board Director Fran Bosch said. "Since we started we have put out close to nine tons of larvacide in aerial applications, and about half that much with the ground crew."

Bosch settled into his new position on April 14 and has been working with a team of six to keep these pests at bay. They are trying new methods this year, including selective barrier sprays and these aerial larvacide applications, for which they have contracted with Airport Manager Rick Marburger. "The reason Williston has such a problem with mosquitoes is because of the spring melt that comes from Montana," Bosch said. "There is an incredible amount of land and there are places where standing water accumulates like Legion Park, where we recently did an application. We are putting resources where they will be best used."

The team covers about 87 square miles of land.

Bosch said a big problem is 'recruitment,' when they have successfully treated an area and then more mosquitoes blow in on the wind.

"Those hot southeastern winds we had last week were an example of that," he said.

Also, the much-needed rain can sometimes not be so good for the skeeter situation.

"Rain is good for farmers but also creates more breeding sites for mosquitoes," he said of the recent rainfall Williston received.

Beginning the first week of June, the crew's schedule will be switching to 7 a.m. to 4 p.m., whereas currently they begin their days at 6 a.m. He also said the season will be picking up.

"We will be working a lot more once it gets busy," Bosch said. "We will be working some overtime and some weekends."

Bosch said that the old days of using diesel and DDT to treat mosquitoes are very much over. They will be treating water drains with a growth hormone called Altacid, which will inhibit growth in mosquitoes and prevent them from becoming adults. Mosquitoes typically go through four stages of growth, but this hormone will keep them stuck in the first stage.

Ground crews have been hiking up the creeks with 40-pound backpacks to apply larvacide, and Bosch said it is very physically demanding work. They will be retreating the ditches and coulees this week.

Bosch said that they will begin to need overtime and some weekend work.

"We have already had one Saturday application," he said.

The team will also be making use of a map created by WSC students in an introductory Geographic Information Systems (GIS) course onto PDAs to help see exactly where to drop the larvacide so that none is wasted. The map shows main river channels, minor channels and backwaters, frequent standing water and mud flats, and was part of a community service final project for the course.