What's eating my coelogyne pandurata?

Coelogyne pandurata, the black orchid of Southeast Asia, is most threatened by spider mites in warm, dry indoor conditions. Scale insects and mealybugs can colonise its large pseudobulbs and leaves. Slugs and snails may damage plants grown in humid greenhouses. Maintaining high humidity indoors prevents most spider mite outbreaks.

Silvery stippling across large leaves; webbing on undersides; leaves yellow and drop in severe cases Increase humidity; spray with insecticidal soap or neem oil targeting leaf undersides; repeat weekly for three to four weeks.

Hard brown or tan bumps adhered to pseudobulbs and leaf stems; weakened growth and yellowing Scrape off with a soft toothbrush; apply horticultural oil or isopropyl alcohol swabs; repeat every two weeks.

Cottony white deposits at pseudobulb bases and roots; honeydew promotes sooty mould Remove with alcohol swab; drench root zone with neem oil solution; retreat at ten-day intervals.

Irregular holes or ragged edges chewed in new leaves and flower buds, especially at night in greenhouse conditions Handpick at night; use copper tape around pots or iron phosphate slug pellets (pet-safe); remove plant debris where slugs shelter.