Gladiolus gall midge

The Gladiolus gall midge (Gladiodiplosis gladioli) is a specialized insect pest belonging to the Cecidomyiidae family, order Diptera. This tiny midge poses a significant threat to gladiolus cultivation, specifically targeting the corms and affecting both the storage and early growth stages of the plant.

This pest is highly host-specific, primarily infesting plants within the Gladiolus genus. The damage is most critical in the subterranean parts of the plant, including corms and cormels, which are essential for the plant's propagation and subsequent flowering success during the next growing season.

The biology of the midge is closely tied to the storage environment. Adult females deposit eggs on the surface of the bulbs or under the tunic scales. Upon hatching, the larvae penetrate the plant tissue and feed by sucking nutrients. In warm, poorly ventilated storage conditions, multiple generations can complete their life cycle, leading to extensive damage.

Visible symptoms include small, depressed lesions or necrotic spots on the corm surface. As the larvae feed, they create tunnels, weakening the structure of the bulb. This physiological damage often creates entry points for secondary fungal and bacterial rot, which rapidly destroys the bulb and renders it unsuitable for planting.

Effective management strategies should focus on prevention and sanitation:

• Store gladiolus corms in cool, dry conditions with adequate air circulation.
• Regularly inspect the storage lots and promptly remove any infested or rotten material.
• Treat corms with registered systemic insecticides prior to planting.
• Maintain proper crop rotation to break the pest's life cycle in the garden soil.