505 ILCS 90/14

All trees, shrubs, vines, cuttings, scions, grafts, plants and plant parts, plant products and places within this State, infested with injurious insect pests or infected with plant diseases which are liable to spread to other plants, plant products or places to the injury thereof, or to the injury of man and animals, and all species and varieties of trees, shrubs, vines and other plants not essential to the welfare of the people of the State which may serve as favorable host plants, and promote the prevalence and abundance of insect pests and plant diseases, or any stage thereof, injurious to other plants essential to the welfare of the people of this State, are hereby declared to be a nuisance.