Chrysanthemum fruit fly

Systematic position: The species belongs to the order Diptera and the family Tephritidae (fruit flies). Unlike many other Tephritidae that feed on fruits, Trypeta zoe is a leaf-mining specialist, primarily targeting members of the Asteraceae family.

Host plants: The primary host is the genus Chrysanthemum. However, the pest is also known to infest wild relatives, including common groundsel and coltsfoot. These wild hosts often serve as reservoirs that facilitate the spread of the fly into greenhouses and gardens.

Biology and life cycle: Adults are small flies that deposit eggs into the leaf epidermis. Upon hatching, the larvae immediately begin mining the leaf tissues, consuming the mesophyll. After completing their larval development, they typically pupate either within the leaf mine or drop into the soil, where they survive until the next generation emerges.

Character of damage: The presence of larvae is evidenced by serpentine, pale tunnels or blotches on the foliage. These mines disrupt photosynthesis and can lead to secondary infections. Severe infestations result in significant yellowing, shriveling, and premature drop of leaves, which drastically affects plant vigor and ornamental value.

Control measures:

• Sanitation: Regularly monitor plants and manually remove or destroy mined leaves to break the life cycle.
• Weed management: Clear nearby weeds that act as alternative host plants to minimize colonization.
• Soil cultivation: Tilling the soil around plants in late autumn can expose and kill overwintering pupae.
• Chemical control: Apply systemic insecticides when adult activity is detected to prevent egg-laying.
• Monitoring: Use sticky yellow traps to detect the presence of adults and time your treatment applications effectively.