How to Identify and Treat Spider Mites on Orchids?

Spider Mites are microscopic creatures, they’re impossible to detect until they’ve wreaked their damage. A plant under attack will have a silvery shine on the underside the leaves, indicating the loss of sap. It is important to use a spider mite treatment as soon as possible on an affected plant in order to keep the plant looking its best and healthiest.

Types and their Identification:

Brevipalpus Californicus: The first observable injury from this mite feeding on orchid leaves appears as silvery areas that eventually become sunken and brown. Individuals of B. californicus are difficult to see because they lie flat against the leaf and move slowly.

Phalaenopsis mite (Tenuipalus pacificus): This is one of the false spider mites, which do not spin webs. This mite is a pest in California, Florida, Panama and some European countries. Feeding by these mites causes dark spots on leaves and eventual tissue death.

Two-spotted Spider Mite, also known as the Red Spider Mite (Tetranychus urticae) These mites are greenish-yellow, wingless, eight-legged creatures with a dark spot on each side of their bodies. They feed on leaf undersides and suck the chlorophyll out of plant cells. These mites thrive when plants are stressed under warm, dry conditions, but they are less of a problem under conditions of high humidity. Two-spotted spider mites are most often found on new growth and on thin-leaf orchids.

A good way to tell if you have mites is to wipe a white cloth or tissue over both sides of a leaf of a plant suspected of mite infestation. If mites or their eggs are present, reddish or brownish streaks will be seen on the cloth. Another test is to tap a leaf over a piece of white paper and see if any of the dislodged particles move. A good magnifying glass is recommended with this test.

Mites can severely weaken plants, as well as disfiguring them. Mites damage orchids by removing sap and chlorophyll with their needlelike mouthparts. It is this withdrawal of chlorophyll that results in the characteristic blanching and silvery appearance of the leaf. Their sap sucking can also cause bruised-looking areas on flowers. Because of their feeding style, they are also potential vectors of diseases.

Prevention:

• The first line of defense against mites is to raise the humidity in the growing environment. Mites are usually most severe on plants in heated greenhouses or in the home during the winter, when the air is quite dry and there are no natural enemies to keep them under control.

• The best prevention for any plant problems, whether pest-related or disease-related, is to keep your plants as healthy as is possible. The more healthy your plant is, the better it will resist.

• If you are growing houseplants or have plants inside a greenhouse or grow room, remove any dust from the plant’s leaves at least once a week with a lightly-moistened cloth. That tends to prevent mite infestation since you’re regularly cleaning the leaves.

Treatment:

• Remove leaves that are heavily infested. Clean the plant. Use mixture of alcohol and water to remove and kill visible spider mites.

• Dilute 1 cup of alcohol in 30 oz of water and pour this solution in the spray bottle. Spray both sides of leaves well and wipe them off with the paper towel.

• Most insecticides have little effect on mites, but a number of chemicals (called acaricides or miticides) are developed specifically for mite control. These are useful in controlling large populations of mites. We recommend using Oberon Insecticide to treat mites Infestation. Dilute 0.5 ml of Oberon per litre of water and spray on the leaves of the infected plant once in seven days until it cures.

Plants with mite damage to only a few leaves will recover quickly and without special care, but those with more significant damage will become stressed and require extra attention. Make sure that all plants get the necessary amount of sunlight for the variety. Feed plants a balanced fertilizer, Such as 20-20-20 until the plant starts producing new, healthy leaves, avoid transplanting or making any major changes to the plant environment.