Pohutukawa mealybug

Acanthococcus pohutukawa is a specialized scale insect belonging to the Eriococcidae family, order Hemiptera. It is primarily recognized as a significant pest of the Metrosideros species, particularly the iconic Pohutukawa tree, often causing severe physiological stress to infested plants.

The primary hosts of this pest include various ornamental evergreen trees within the Metrosideros genus. Due to its sedentary lifestyle and the formation of protective structures, the insect can remain unnoticed for long periods, leading to widespread infestation within gardens and nurseries.

The life cycle involves distinct stages including eggs, nymphs (crawlers), and sessile adults. Females produce a white, felt-like ovisac where they deposit eggs, protecting them from environmental fluctuations and many contact insecticides. The crawler stage is the primary vector for spreading the infestation to nearby foliage.

Damage caused by this pest includes sap depletion, which leads to chlorosis, stunted growth, and canopy thinning. Additionally, the excretion of honeydew promotes the growth of sooty mold, which covers the leaf surface and further hinders photosynthesis, resulting in significant aesthetic and structural damage.

Effective control measures require a combination of cultural and chemical strategies. Key management practices include:

• Pruning and destroying heavily infested branches.
• Applying systemic insecticides to reach sheltered insects.
• Using horticultural mineral oils during the crawler emergence phase.
• Maintaining plant vigor to increase natural resistance.

Early detection remains the most critical factor in managing this pest. Regular monitoring of the underside of leaves and twigs for the presence of white felt-like sacs is essential for successful eradication and limiting the economic impact on nursery stock.