Seed fly

The genus Earomyia belongs to the Lonchaeidae family of the order Diptera. These flies are notable for their specialized larvae that develop inside the seeds of various trees, primarily conifers, making them a significant concern for silviculture and seed orchard management.

These pests primarily target conifer cones, such as those of spruce and pine. The larvae feed on the developing seeds, boring through the interior of the cone scales. This internal feeding process destroys the seed embryo, rendering the entire cone unproductive for reforestation purposes.

The life cycle of Earomyia is strictly tied to the phenology of the host plant. The adults emerge in spring to mate and lay eggs on developing cones. Larval development takes several weeks, during which they consume the endosperm of the seeds. Once fully grown, the larvae exit the cones to pupate in the forest litter or soil.

The damage caused by these insects is often overlooked until the harvest stage. Infested cones show premature yellowing or necrosis. Economic loss is substantial, as the fly directly impacts the viability and yield of high-quality seeds, which are essential for sustainable forestry and nursery stock production.

Effective management and control strategies include:

• Sanitation cuttings to remove infested cones before larva emergence.
• Timed applications of systemic insecticides during adult mating activity.
• Monitoring using yellow sticky traps or pheromone baits.
• Promoting biodiversity in forests to encourage natural predator populations.