The gladiolus thrips is one of the most serious pests attacking gladiolus.
Damage occurs both to the corms in storage and to the growing plant.
Infested corms are sticky, corky and russeted by the feeding of the thrips, and sometimes small rootlets are injured. Such damage usually results in a retardation of growth, poorer flowers, and smaller corms. Some corms may fail to germinate. The growing plants show whitened or silvered streaks on the leaves and flowers due to the thrips feeding. Buds may be injured so severely that they never open normally, they turn brown and the bud sheaths dry out and become straw-colored.