By August the basin's yellowjacket colonies have grown from a lone queen in May to thousands of workers, and every one of them is hungry, short-tempered, and drawn to the same picnic you are. A nest in a Klamath Falls lawn, a paper-wasp comb under a Running Y deck rail, a yellowjacket hole in a Merrill ditch bank, a bald-faced hornet nest the size of a football in an Altamont juniper — these are same-week jobs, and a licensed local pest operator who runs stinging-insect calls all summer rings back with a free quote and, usually, a day.
Three animals, three different jobs
Yellowjackets are the ground nesters — the hole in the lawn, the gap in the retaining wall, the void under a shed floor — and the ones that sting in numbers when a mower passes. Western yellowjackets are the basin's dominant species and the reason a Klamath County barbecue in September is a contact sport. Paper wasps hang the open, umbrella-shaped combs under eaves, deck rails, and mailbox lids; they're calmer, but a comb over a front door gets defended. Bald-faced hornets build the gray, closed paper ball in trees and shrubs, and they defend it hard from a distance. Each nest is treated at its own time and by its own method — a ground nest at dusk when the workers are home, an aerial nest with the right dust into the entrance, a comb knocked down after treatment and the spot treated so the next queen doesn't like it either. A licensed applicator in Oregon carries the products and the training to do all three; a can from the hardware store handles one paper-wasp comb on a good day.
What not to do while you wait
Don't pour gasoline in the hole — it's a fire, a lawn scar, and in a county this dry a genuine risk. Don't seal a nest entrance in a wall; yellowjackets will chew through drywall to find another way out, and that way is often your living room. Don't mow over it again. Mark it, keep the dog and the kids off that side of the yard, and describe it on the phone: ground or hanging, gray paper or open comb, roughly how big, how many are coming and going. That description is most of the quote, and the quote is free.
Timing and the end of the season
Colonies die with the hard freeze, which in Klamath Falls comes early; the pressure runs hottest from late July into October and then stops on its own. That doesn't mean waiting is wise — a nest near a door in August is six more weeks of stings — but it does mean a spring visit can matter more than people expect, since queens pick nest sites in May and an exterior treatment then keeps eaves and voids unattractive. That's why stinging-insect work sits in the summer quarter of a recurring program for Klamath County homes. Honey bees are not on this page: a swarm on a fence or a colony in a wall is a job for a beekeeper, and an operator on this bench will tell you so and help you find one.