There are several species of spider mites that infest orchids. They are very small and difficult to see, even with a magnifying glass! But the damage they do is easily recognizable. Red spider mites and several species of false spider mites are probably the worst of pests for orchid plants.
SIGNS OF INFESTATION
They pierce the leaf tissue and suck out plant juices like a mosquito leaving behind silvery sheen indents under the leaves due to the death of superficial plant cells. Not all spider mites make webs.
You may also observe brown or black marks on the leaves which is caused by a secondary bacterial or fungal infection followed by mite attack as plant is by now at weakened state.
PREVENTION
Mites multiply rapidly in warm and dry conditions. They are generally evident in hot and dry summer season. Therefore, the best way to control mites is to increase the humidity in a greenhouse by adding more plants or by misting regularly.
Spider mites hang out on the undersides of leaves and on the lower, older leaves of orchids. They move slowly and may live on that same leaf for their whole lives. So make sure to inspect your plants at fixed intervals for any signs of infestation.
METHODS OF CONTROL
Treatment of all pest attack starts with the following:
- Isolate the plant from other plants in your collection.
- If you find a new pest, be sure to identify it correctly. Different pests require different control methods.
- Chemical treatment with the following on all plants in your collection.
When symptoms are detected, spraying with a pesticide such as the following are effective :
Incase of mild infestation:
- Chemical name: Propargite (Brand name: Omite)
- Dosage: 1ml per litre of water
If infestation is severe use the following:
- Chemical name: Spiromesifen (Brand name: Oberon)
- Dosage: 1ml per litre of water
Keep the plants drier and isolate the plants to keep the infestation from spreading or appearing again. Isolate the plants and observe the plants for 1-2 weeks. And apply another round of control spray with any of the above chemicals. Spray the plants early morning and keep the plants dry after the spraying. Don't water the plants same day spray treatment is done.
