Spokane is among cities that have restricted use of pesticides that are chemically similar to nicotine because they may be killing bees.
The City Council in late June voted to ban city purchase and use of neonicotinoids. The ban does not apply to private use.
The ban covers about 30 percent of the land in Spokane, including streets, parks and rights of way.
Last year Eugene, Oregon, became the first city in the nation to ban use of neonicotinoids.
The nicotine-like insecticide has been around for years and is popular because of its low toxicity in mammals, birds and other higher-order animals. But several recent studies have indicated that prolonged exposure to neonicotinoids may build up in bees and other beneficial insects.