Jayson Jacoby
The Baker City Herald

Spring can be the most fickle of seasons, with scalding sunshine and chilly rain squalls sometimes sharing the same day, but for the mosquito killers what matters is water.

Standing water, to be specific.

That’s where mosquito larvae live and it’s where, if Matt Hutchinson has his way, they will die.

And so whatever the weather, once the irrigation season starts in the Baker, Bowen and Keating valleys, Hutchinson and his crew will start their seasonal task in earnest.

Hutchinson manages the Baker Valley Vector Control District, which, notwithstanding its name, covers about 200,000 acres in those three valleys.

The purpose of the district, which receives about $280,000 yearly in property taxes, is to control mosquitoes, some of which can spread West Nile virus and other diseases to people, horses and other animals.

Hutchinson, who is starting his sixth season as the district’s manager, expects this year’s mosquito crop to be about average.

Which is something of a welcome change from 2017, when prodigious snow during the winter left thousands of acres of waterlogged ground in the district in spring — ideal conditions for mosquito larvae to mature into biting adults.

“Last year there were definitely more fields with runoff water on them,” Hutchinson said. “This year not so much.”

When widespread irrigation started a couple weeks ago, Hutchinson and his two seasonal employees — he expects to hire a third soon — started spreading a granular insecticide that kills mosquito larvae.

The goal is simple, even if achieving it isn’t — kill the larvae, which don’t bother people, before they hatch into the flying bugs that most certainly do.

So far the work has been done from the ground, but aerial spraying — from a fixed-wing airplane — of the granular insecticide has also started.

The plane will target areas in the northeast part of Baker Valley, he said.

Hutchinson said the shift from flood irrigation, which creates the standing water mosquitoes prefer, to center-pivot sprinkler systems has reduced the acreage he needs to treat.

“But there is still a lot of flood irrigation,” he said.