Alfalfa tortrix

The Alfalfa tortrix (Cacoecia divulsana) is a moth species belonging to the order Lepidoptera and the family Tortricidae. It is recognized as a significant agricultural pest, specifically impacting legume crops, with a high preference for alfalfa (Medicago sativa) in various agricultural regions.

This insect primarily infests alfalfa fields. The larvae feed on the foliage, buds, and flowers of the plants. By causing defoliation and destroying reproductive structures, the pest directly reduces both the biomass yield and the seed production potential of the affected fields.

The biological development of this species includes four distinct stages: egg, larva, pupa, and adult. Females typically deposit eggs on the undersides of leaves or on terminal shoots. Once hatched, the larvae begin feeding and utilize silk to tie leaves together, creating protective shelters or rolls where they continue their development.

Damage is characterized by the presence of rolled, webbed leaves that eventually turn necrotic and brown. Infestation severity is measured by the percentage of damaged buds and the extent of leaf rolling. High populations can lead to severe crop stress and significantly impact the overall nutritional quality of the forage.

Integrated Pest Management (IPM) is essential for controlling Cacoecia divulsana.

• Regular field monitoring to detect early egg-laying activity.
• Timely mowing of alfalfa crops to disrupt the life cycle of the larvae.
• Judicious use of chemical insecticides, applying them only when economic thresholds are exceeded, and ensuring the protection of beneficial pollinators.