|Two-spotted spider mites
|Discoloured foliage, fine web appears. Mostly affects Cymbidium.
See fact sheet.
False spider mites or flat mites Brevipalpus russulus
|Pits on upper leaf surface.
|Same treatment as for two-spotted spider mites. See fact sheet.
|Spotted or deformed flowers or none at all. Aphids like young shoots and flower spikes.
|See fact sheet.
|Mealybugs, scale insects Pseudococcus longispinus, Diaspis boisdevalii
|Powdery white mass in leaf axils; small brownish shells all over the plant.
|See fact sheet.
|Black spots on flowers.
|See fact sheet
Cercospora sp. / Gloeosporium sp.
|Round brown or black spots on the upper or under surface of leaves, sometimes on tips.
|Improve air circulation. Wipe off any water remaining on leaves after watering. If possible, remove the worst-affected leaves.
|Centre of plant turns black and rotten. Leaves pull off easily.
|Destroy plant. Disinfect all tools.
|Slightly damp brown spots on leaf surface. Affect mostly Phalaenopsis and Paphiopedilums.
|Remove infected parts. Disinfect all tools.
|Mosaic or necrotic rings on leaves, stunted growth and deterioration of the plant, mottled or streaked flowers.
|No effective treatment. Destroy plant. Disinfect all tools.
|Dark green leaves. Poor or no flowers. New shoots smaller.
|Increase light intensity..
|Too much light
|Yellowed leaves. Whitish burns on upper surface of leaves. Slow growth.
|Decrease light intensity.
|Wilted leaves and pseudobulbs. Deformed leaves.
|Increase frequency of waterings
|Too much water
|Wilted leaves and pseudobulbs. Leaves turn yellow and drop off. Roots deteriorate.
|Decrease frequency of waterings, repot and remove affected parts.
|Lack of humidity
|Wilted leaves. Shrivelled leaves.
|Mist leaves. Use a humidifier or place the plant on a bed of gravel in a water-filled saucer.
|Too much humidity
|Leaf spots and black spots on pseudobulbs.
|Improve air circulation. Remove affected parts.
|Sudden drop in temperature
|Leaf spots, tips of leaves brown.
|Protect from drafts.
|Yellowed leaves. Slow growth.