Paul Heidtke has a simple way to check whether mosquitoes are getting thick. He steps out of his truck.

He did so late last month in La Pine and quickly knew the answer.

“I probably had 15 mosquitoes on me in 45 seconds,” said Heidtke, president of Terminix of Central Oregon.

The company is on contract with La Pine to roll over all 31 miles of its roads and put out a toxic fog designed to kill mosquitoes. The weekly fogging started last month and will go until August, said Steven Hasson, manager of the small city south of Bend.

“I think it’s working, or else I’d be getting complaints,” he said.

La Pine isn’t the only Central Oregon community contending with the bloodthirsty, annoying insects of summer. Attacks on mosquitoes are also under way in swamps near Sunriver and in standing water in pastures near Prineville, where vector control districts are trying to kill them before they take flight.

Mosquito season here typically starts in southern Deschutes County — where meandering rivers create breeding waters — before it does in Bend and the surrounding high mountain lakes, said Chad Stubblefield, director of the Four Rivers Vector Control District. The district tries to limit the number of mosquitoes from a mile north of Burgess Road in La Pine to the north end of Sunriver, near Benham Falls.

Wet weather this spring brought high flows along rivers in southern Deschutes County, which left swampy pools of water in low-lying areas, Stubblefield said.

“The standing water was plentiful along the Little Deschutes River, and that made for a bad spring as far as mosquitoes go,” he said.

But that doesn’t necessarily mean Bend will see the same, he said. The weather systems that dropped rain on Central Oregon this spring and early summer also brought cool temperatures.

“If anything, this cold weather has given us a shorter mosquito season rather than if we had a hot June,” Stubblefield said.

While it may take them awhile to hatch, there likely will be plenty of mosquitoes this year in Central Oregon forests.

The wetter the year, the more breeding habitat around the woods, said Andy Eglitis, an entomologist with the U.S. Forest Service who studies insects in Central Oregon.

“We’ve had enough moisture that this could be a good year for mosquitoes, bad year for us,” he said.

Around the house, Central Oregonians can lessen the likelihood of a mosquito menace by making sure they don’t have standing water, said Cliff Kiser, manager of the Crook County Vector Control District.

“Anything that has been sitting for three or four days can be a source of mosquitoes,” he said.

Like the Four Rivers Vector Control District, Kiser says his district, which tries to cut the number of mosquitoes near Prineville, starts by attacking mosquito larvae in the spring and early summer before using a chemical fog to kill adult mosquitoes later in the season.

But “nothing is 100 percent, so the mosquito population grows throughout the summer,” he said.

Mosquitoes typically hang around Central Oregon until there have been a couple of killing frosts in the fall.