Raspberry cane midge

The raspberry cane midge (Lasioptera rubi) is a significant pest belonging to the order Diptera and the family Cecidomyiidae. It is well-known for creating abnormal, tumor-like growths, known as galls, on the stems of raspberry and blackberry plants, which disrupt the normal development of the host.

This pest is found in many regions where raspberries are cultivated. Its host range is primarily limited to species within the Rubus genus. The midge is a monovoltine insect, meaning it completes one generation per year, with the larvae overwintering inside the characteristic stem galls formed during the previous growing season.

The lifecycle begins when the adult female lays eggs in the cracks of the bark on young canes. Upon hatching, the larvae penetrate the stem tissue. Their feeding activities trigger the plant's defense response, resulting in the development of woody, irregular galls that typically measure several centimeters in length.

The damage caused by the raspberry cane midge is both physical and physiological. The galls interrupt the flow of water and nutrients, which can lead to the wilting and death of the upper parts of the canes. Additionally, these stems become structurally weak and are prone to snapping under the weight of fruit or in windy conditions, leading to substantial yield losses.

Integrated pest management strategies are essential for controlling this insect. Recommended practices include:

• Routine inspection of canes during the pruning season to identify and remove all galled stems.
• Burning or deep burying of infested canes immediately after cutting to kill overwintering larvae.
• Maintaining healthy planting conditions to improve the natural vigor of the raspberry bushes.
• Applying systemic or contact insecticides during the emergence period of adults if the infestation level is critical.
• Ensuring that new plantation material is sourced from certified, pest-free nurseries.