Sioux Falls sees nearly 70% decrease in mosquitoes after days of spraying citywide

Sioux Falls is seeing a sharp downturn in mosquitoes following city-wide sprays that took place as the flying pests swarmed the city, buoyed by flooding and warm temperatures.

The city has a mosquito trap in each of the 18 "spray zones" around the city that allow for mosquitoes to be captured, counted and tested.

On July 5, the city's traps had 15,000 mosquitoes. And by July 8, the number had gone as high as 18,000, according to data shared by Communications Strategist Megan Forster.

July 8 was also when the first of two citywide mosquito sprays began, running through July 11 and then starting again on July 15-16.

By July 11, the city's traps showed 9,500 mosquitoes. By July 12, they were down to 5,800, a nearly 70% drop from the high earlier that month.

More: Sioux Falls sees uptick in mosquitoes that could carry disease, public health director says

Public Health Director Joe Kippley said last week that sprays had been used because of the amount of “nuisance” mosquitoes present as well as those able to transmit diseases, including West Nile Virus.

In addition to flooding and heavy rains giving mosquitoes plenty of standing water in which to breed, Kippley said it had also washed away much of the larvicide that had been placed to get rid of the bugs before they hatch, with crews working to get it back in place in the daytime while sprayer trucks run at night.

This article originally appeared on Sioux Falls Argus Leader: Sioux Falls sees nearly 70% decrease in mosquitoes after days of spraying citywide