Cypress gall midge

Systematic position: The cypress gall midge, Resseliella odai, belongs to the order Diptera and the family Cecidomyiidae. It is a highly specialized insect pest that targets trees and shrubs within the Cupressaceae family.

Host plants: The primary host plants include various species of the genus Cupressus and Cryptomeria. These pests are particularly problematic in nurseries, landscaping projects, and ornamental tree plantations where high plant density favors rapid infestation.

Biology and life cycle: Adult midges are small, fragile insects. Females lay eggs under the bark scales or within pre-existing cracks in the shoots. Upon hatching, the larvae tunnel under the bark to feed on the cambium layer. Depending on the local climate, the insect can complete several generations throughout the growing season.

Damage and harmfulness: The larvae cause significant mechanical damage to the cambium, which disrupts nutrient and water transport. Typical symptoms include chlorosis (yellowing), wilting of twigs, and dieback of branches. Severe infestations can lead to weakened tree health, making them susceptible to secondary pathogens and eventual tree death.

• Implementation of regular monitoring using sticky traps to detect adult midge activity.
• Sanitary pruning of infested branches, followed by immediate removal or destruction.
• Application of systemic insecticides to target larvae feeding under the bark.
• Enhancing tree vigor through proper irrigation and fertilization programs.
• Use of biological control agents that target immature stages of the gall midge.