Apple sawfly

The apple sawfly (Latin: Hoplocampa alpina) is a significant insect pest belonging to the order Hymenoptera and the family Tenthredinidae. This species is known for targeting fruit crops, specifically apples, causing severe economic damage to orchards by affecting the reproductive development of the trees.

The host range is largely limited to the genus Malus (apple trees). The biological cycle of the sawfly is precisely timed with the host plant's flowering stage. Adults emerge during spring, coinciding with the opening of blossoms, which provides the necessary conditions for the female to deposit her eggs into the flower tissues.

Regarding its life cycle, the insect completes one generation per year. It overwinters as a mature larva inside a cocoon within the soil at a depth of 15–20 centimeters. Transformation into a pupa occurs in early spring, followed by the emergence of adults, which marks the start of the primary infestation period for the season.

The damage caused by the larvae is distinct and destructive. Upon hatching, the larvae bore into the developing fruitlet, often creating a hole filled with brown excrement. A single larva can migrate between several fruits, rendering them non-viable and causing premature fruit drop. This migration behavior is a key factor in the high level of harvest loss.

Effective management strategies require a combination of cultural and chemical interventions. Preventive measures are essential for long-term population suppression.

• Cultivating the soil beneath tree canopies in autumn to destroy overwintering cocoons.
• Applying systemic or contact insecticides during the pre-blossom stage.
• Monitoring pest activity using white sticky traps.
• Promptly removing and disposing of infested fruitlets from the orchard floor.