Oleander scale

Oleander scale (Aspidiotus hederae) is a prominent member of the Diaspididae family within the order Hemiptera. This pest is widely recognized as a serious economic threat to ornamental plants in both greenhouse environments and warmer outdoor climates, where it can cause significant aesthetic and physiological damage.

The host range of this insect is extensive, encompassing a vast array of ornamental and economic crops. Common hosts include Oleander (Nerium oleander), Ivy (Hedera helix), Palms, Citrus, various succulents, and numerous indoor plant species. The pest typically colonizes leaves, stems, and fruits, establishing itself in dense colonies.

The life cycle begins with the egg stage, followed by the mobile crawler stage (nymph) and the sedentary adult stage. Female scales develop a hard, waxy, circular or oval shell that provides excellent protection against contact pesticides. The crawlers are the primary means of infestation as they actively seek out suitable feeding sites on the host plant.

Damage is caused by the insect inserting its piercing-sucking mouthparts into the plant tissue to extract sap. This feeding process deprives the plant of essential nutrients, leading to chlorosis, stunting, leaf drop, and overall vigor decline. Heavy infestations can cause twigs and stems to die back, significantly reducing the market value and health of the plant.

Management strategies require an integrated approach to be successful. Key methods include:

• Quarantining new plants to prevent infestation spread.
• Physical removal using soft brushes soaked in insecticidal soap or rubbing alcohol.
• Application of systemic insecticides that are absorbed into the plant sap.
• Use of horticultural oils to suffocate the sedentary stages of the scale.