Murraya scale

The Murraya scale (Aulacaspis murrayae) is a dangerous specialized pest belonging to the order Hemiptera and the family Diaspididae. This insect is characterized by a tough, protective shield that covers the female's body, providing significant defense against various environmental factors and many contact insecticides.

The primary hosts for this pest include species of the genus Murraya, as well as various types of citrus plants. The scale typically settles on leaves, stems, and fruits, where it pierces the plant tissue to feed on cell sap, which leads to the severe weakening and physiological decline of the host plant.

The life cycle of Aulacaspis murrayae consists of the egg, nymph (crawler), and adult stages. The crawler stage is critical, as it is the phase during which the insect actively spreads across the plant and disperses to neighboring ones. Under favorable conditions, such as in greenhouses or indoors, reproduction can occur continuously throughout the year.

Damage symptoms include yellowing and premature leaf drop, as well as the deformation of young shoots. During heavy infestations, the scales form dense colonies that appear as light or brownish crusts on the bark. Due to constant sap extraction, the plant's growth is stunted, and affected fruits lose their market quality and consumption value.

To effectively manage and control the Murraya scale, a multifaceted approach is recommended:

• Regular inspections of plants to ensure early detection of infestation hotspots.
• Mechanical cleaning of bark and pruning of heavily infested plant parts.
• Application of systemic insecticides that are transported within the plant's sap.
• Use of horticultural mineral oils to smother the scale insects.
• Strict adherence to quarantine protocols for all new plant material.