What causes plant galls associated with insects and mites?

Plant galls associated with insects and mites are primarily caused by the feeding and egg laying activities of these pests. When certain insects or mites, such as aphids, gall midges, or leafhoppers, feed on a plant, their saliva can introduce compounds that disrupt the plant's normal growth patterns. This disruption prompts the plant to produce a gall, which is an abnormal growth or swelling. The gall serves as a protective environment for the insect or mite, providing food and shelter as it grows and develops within the gall structure.

This process is a fascinating interplay between the pest and the plant, showcasing how certain pests can manipulate plant physiology for their benefit. Galls can vary in shape, size, and color depending on the species of insect or mite involved, and they can appear on various parts of the plant, including leaves, stems, and roots. Understanding this relationship is crucial in ornamental and turf pest management, as it helps in identifying pest issues and choosing effective control methods.