Spider Mites

Red spider mites are the bane of the lives of houseplant growers. They love dry air and underwatered plants so they are rife in our centrally heated homes. How do they get in? It could be via infected new plants, or they could just drift in on the breeze through an open window. They are almost microscopically small, and you’ll likely see the damage before you see them. Tell tale signs are fine silver pitting and spotting on some leaves followed by yellowing and premature leaf drop. You might also spot webbing between leaves and stem if you look closely. If you’re suspicious, use a spray gun of water on the leaves and the extent of the webbing will become apparent. You might also notice fine brownish dust on some leaves which is the frass (droppings) and shed skins of the mites. Take a piece of white paper, hold it under a leaf and give the leaf a shake. You’ll soon spot it. If you’re a glutton for punishment, use your hand lens or your phone’s camera zoom and you’ll see the creatures themselves crawling around. Luckily for orchid growers, they only go for a few types, and they tend not to be an issue in humid places with well watered plants. If you grow Cymbidium, Catasetum and allies, Calanthe or a few others you might see spider mites occasionally. They mostly go for thin leaved deciduous orchids. They are easily deterred by keeping the humidity up or spraying your plants.