Boards of county commissioners in the various counties of this state are authorized and empowered and it is hereby made their duty whenever a petition is presented to them signed by twenty-five fruit growers, owners of orchards and residents of the county, stating in substance that there is danger in the introduction in said county of the “codlin moth,” or other worms or insects destructive to fruit by reason of the shipment of apples or other fruits into said county, and when said commissioners upon examination are satisfied of the truth of the petition presented, they may by proclamation prohibit the shipment of fruit into said county by an imposition of a license or other lawful means, which said commissioners may deem best and most effective to accomplish the purpose of this chapter.