Any and all neglected or abandoned trees, vines, shrubs, plants or parts thereof, which because of the existence therein or thereon of injurious or destructive insect pests, or plant diseases or other conditions which may constitute a menace to the horticulture or agriculture of the county, district, or vicinity or which are host plants of or provide a favorable and likely harbor for such pests or diseases, which, if they become established upon such neglected or abandoned host plants or crops, would be a menace to agriculture or horticulture, are hereby expressly declared to be public nuisances, and it shall be unlawful to maintain the same, and all remedies which are or may be given for the prevention or abatement of the nuisance shall apply thereto.