Raspberry sawfly

Systematic position. The raspberry sawfly (Latin Monophadnoides geniculatus) belongs to the order Hymenoptera and the family Tenthredinidae. It is a specific pest that targets shrub species within the Rosaceae family, causing significant economic damage if left unchecked.

Affected crops. This pest primarily attacks raspberries, although it can also affect blackberries. The larvae are voracious leaf-feeders, often found on the undersides of the foliage, where they feed in groups or individually, causing visible damage to the plant's vegetative parts.

Biology and life cycle. The adult is a small, black hymenopteran insect. Overwintering occurs in the soil as larvae within protective cocoons. Pupation happens in early spring, and adults emerge synchronously with the development of the host plant's foliage. Eggs are laid in rows within the leaf tissue, ensuring that larvae have immediate access to food upon hatching.

Nature of damage. The larvae cause characteristic damage by chewing irregular holes in the leaves. In cases of high infestation, they skeletonize the leaves, consuming everything except the veins. This defoliation reduces the photosynthetic capacity of the plants, directly impacting fruit quality, sugar content, and overall vigor of the raspberry canes.

Control measures. Integrated pest management (IPM) is essential for effective control:

• Cultivating the soil beneath the bushes in autumn to disrupt overwintering sites.
• Hand-picking and destroying infested leaves at the early onset of damage.
• Using biological insecticides, such as bacteria-based formulations, during early larval stages.
• Applying systemic or contact insecticides during the pre-flowering phase if pest pressure thresholds are exceeded.