What are Spider mites or mites, and what should I do about them?
Mites damage orchids quickly and quietlyoften their presence is not noticed until significant damage has occurred. Mites are visible, but their presence is easily determined by rubbing a white cloth over the area that is damaged. If mites or their eggs are present, a brownish residue will be left on the leaf. This will come off and be visible on the towel. Some spin light webs which are visible on the plant or at the base of the plant.
A very good natural remedy is an oil/soap treatment. Dr. Martin Motes recommends using a light oil--such as vegetable oil. Olive oil is very heavy and could potentially damage plants. Using 2 TBS oil/gallon is sufficient, you can add a teaspoon of baking soda for a bit of antifungal. Remember to keep shaking the solution in the container to keep the oil mixed with the water. Spray thoroughly on all sides of the leaves.
FOLLOW UP with a soap solution about 7 days later. Using 2 tsp/gallon of Joy or Dawn (dog shampoo is great too) not only does a number on the pests, it helps clean off the oil treatment. I actually follow up with a third treatment in another week with the same soap solution.
The soap/oil mixture remedy has been shared in the past, but the University of Florida recently discounted it as the two agents act in direct opposition of each other and essentially decrease the effectiveness of the effort. Just like the TV ads say, the dishsoap is designed to cut grease (oil) in its tracks! :)
AOS recommends Malathion, or Volk Oil/Sunspray for scale. Also Knox Out 2 FM or Orthene Turf, Tree and Ornamental Spray. Mites are nasty buggers to get control over. If the infestation is confined to one plant, isolate it to prevent spreading--watch for that carefully. Be careful to follow the label on preparations TO THE LETTER to avoid damage to plants.
One tip for success is to make sure you do TWO treatments of your selected poison about 7-10 days apart in order to catch newly hatched pests.
Submitted by Rhonda Heide