Mealybugs on orchids: Mechanical cleaning and systemic insecticide to save plants

Small, white, cotton-like clusters appearing on an orchid are rarely a natural feature of the plant. These deposits typically serve as the first visible indicator of a parasitic infestation that can compromise the plant's vascular system if left unchecked. Identifying the Culprit The primary suspect in such cases is the mealybug. Female mealybugs are 2-5 mm long, with rounded or oval bodies colored white or light grey, appearing as if dusted with flour. While larvae are smaller, they share this distinctive appearance. In contrast, males resemble tiny flies. The diagnostic hallmark of an infestation is the presence of these "cottony" aggregations on the foliage and stems. Mechanism of Damage Mealybugs feed by extracting sap directly from the leaves and roots. This systemic depletion leads to several observable failures: