Orchid scale

Orchid scale (Latin: Lepidosaphes pinnaeformis) is a destructive insect pest belonging to the order Hemiptera and the family Diaspididae. It is commonly found in greenhouses, botanical collections, and indoor environments, specifically targeting epiphytic orchid species through its specialized feeding habits.

This pest primarily attacks various genera of orchids, such as Cymbidium, Dendrobium, and Cattleya. The insect settles on leaves, pseudobulbs, and stems, creating a protective layer that makes it difficult to detect and eradicate during the early stages of the infestation.

The biology of the orchid scale is defined by its distinct developmental stages: egg, crawlers (mobile larvae), nymphs, and adults. The female develops a rigid, oyster-shaped or comma-shaped shell that protects her throughout her adult life while she feeds on the host plant's sap.

The economic and aesthetic damage caused by this pest is significant. By piercing plant tissues and extracting sap, the scale causes localized yellowing, stunted leaf growth, and general physiological stress. If left unmanaged, the plant loses vigor, becomes susceptible to secondary bacterial infections, and may eventually wither.

Effective management requires a combination of cultural practices and chemical control. Since the protective shell shields the insect from many topical treatments, systemic pesticides are often the most reliable solution. Growers should prioritize these strategies:

• Regular inspection of leaf undersides and pseudobulb crevices.
• Quarantine of all new orchid arrivals for at least four weeks.
• Application of systemic insecticides that are absorbed by the plant.
• Mechanical removal of scale using a soft-bristled brush dipped in isopropyl alcohol.