What's eating my nobile dendrobium?

Nobile Dendrobium (Dendrobium nobile) is a pseudobulb orchid prone to mealybugs, scale, and red spider mites — the top three indoor orchid threats. Mealybugs lodge between canes and in sheaths. Spider mites spike in warm, dry rooms. Thrips occasionally scar the flowers. Inspect all cane nodes at every watering.

White woolly deposits between cane sheaths and at nodes; honeydew, sooty mold, and withered canes if severe Swab each node and sheath with isopropyl alcohol; spray all canes with neem oil weekly for a month; isolate the plant

Hard brown shells fused to canes and pseudobulbs; yellowing and die-back from the cane tips downward Scrub off with alcohol-soaked brush; treat with horticultural oil spray monthly; remove and destroy heavily infested canes

Pale stippling and fine webbing on canes and leaves; worst in heated rooms with very low humidity in winter Raise humidity to 50–60%; mist canes and rinse in the shower; apply insecticidal soap or predatory mites (Phytoseiulus persimilis)

Silvery streaking and scarring on the delicate white-pink flowers; affected blooms shorten their display Remove infested flower spikes; apply spinosad spray; keep plant away from windows that are opened during bloom