All artificial containers and water-holding devices placed so that they may hold water for a period of five days or longer, unless the containers or devices shall be tightly covered or screened to prevent the entry of mosquitoes, shall constitute a public nuisance. It shall be unlawful for any person to maintain on his premises unscreened or uncovered containers, or other water-holding devices, under conditions that permit mosquito larvae or pupae to develop. All uncovered or unscreened containers, or other water-holding devices, shall be completely drained, or the water therein changed at intervals of not more than five days between April l and October 25, or effective insecticides must be applied to all exposed water surfaces at intervals of not more than five days during such period. The failure to maintain the containers or devices free of mosquito larvae or pupae during such period constitutes a violation of this section.
('69 Code, § 15-54)