Cottony scale insect

The cottony scale insect (Poliaspis floccosa) is a pest belonging to the order Hemiptera and the family Diaspididae. It is recognized by the distinct white, cotton-like wax secretions produced by the females to protect their eggs and themselves from adverse environmental conditions and predators.

This pest primarily infests various ornamental shrubs and woody plants. By colonizing stems, twigs, and leaves, the insect draws nutrients directly from the plant's vascular system, which over time severely weakens the host plant's vigor and general health.

The life cycle follows a pattern of egg, crawler (nymph), and adult stages. The crawler stage is the only mobile phase, where the young insects disperse across the host plant before settling down to feed. Once settled, they secrete a hard, protective covering that makes traditional contact pesticide application less effective.

Symptoms of infestation include yellowing leaves, stunted growth, and visible patches of waxy secretions on the bark. If left uncontrolled, heavy infestations can lead to dieback of branches and, in severe cases, the death of the entire plant due to systemic nutrient depletion.

Control strategies require a combined approach to ensure long-term management. Key practices include:

• Regular monitoring of host plants for early detection of crawlers.
• Mechanical removal of heavily infested plant parts.
• Application of horticultural oils during the dormant season to suffocate overwintering stages.
• Timely use of systemic insecticides during the active crawler emergence period.