Steve Lewis/Durango Herald - Joe Kuefler, who manages the Animas Mosquito Control District, said they spray for adult mosquitos at night in order to avoid harming pollinating insects, like bees, who are out in the daytime. Part of the crew sprays on private land on Tuesday night in town near County Road 250 (East Animas Road).

Steve Lewis/Durango Herald - Part of the crew sprays on private land on Tuesday night in town near County Road 250 (East Animas Road).

Steve Lewis/Durango Herald - Rick Jones, left, and Melody Schaaf head to an area adjacent to Dalton Ranch Golf Club to search for mosquito larvae and adult mosquitos on Wednesday afternoon.

Steve Lewis/Durango Herald - Rick Jones, left, and Melody Schaaf look for mosquito larvae on Wednesday afternoon near Dalton Ranch Golf Club.

Steve Lewis/Durango Herald - Melody Schaaf, left, and Rick Jones make their way into a thickly overgrown area near Dalton Ranch Golf Club on Wednesday afternoon.

Steve Lewis/Durango Herald - Melody Schaaf, left, and Rick Jones enter their GPS coordinates after treating an area on Wednesday near Dalton Ranch Golf Club.

Steve Lewis/Durango Herald - Melody Schaaf, front, and Rick Jones make their way through the thicket on Wednesday near Dalton Ranch Golf Club.

Steve Lewis/Durango Herald - Melody Schaaf, back, and Rick Jones attempt to capture adult mosquitos they encountered to determine their species and sex on Wednesday near Dalton Ranch Golf Club.

Steve Lewis/Durango Herald - Melody Schaaf identifies an adult mosquito on Wednesday near Dalton Ranch Golf Club.