June 17, 2010
It would appear that my oregano in the raised beds has been hit with the double whammy of fungus gnats and spider mites. Both are known pests to oregano as are white flies and aphids. At this point all I can say is I'm not amused. At any rate the infestation isn't too bad so can be controlled.
Spider mites are 8 legged, spider-like creatures ranging in colour from black to brown to a rusty orange. They thrive in hot, dry conditions like heated houses but can also be found in outdoor gardens. They feed with piercing mouth parts that cause plants to appear yellow and stippled. Heavy infestations can result in leaf drop and plant death. Spider mites can multiply quickly. Signs of spider mites other than the damage are webs that can cover infested leaves and flowers.
Controlling Spider Mites
- Remove infested plants. This is quite often the best course of action for infested houseplants. Remove them entirely or isolate them from other plants and treat with an insecticidal soap (homemade or commercial).
- Keep plants regularly watered especially those preferring high humidity (eg. tropicals, tomatoes).
- Isolate all new plants coming into the garden or house to be sure they are not infested. If they are infested treat to get rid of spider mites before introducing to the rest of your houseplants or garden.
- Introduce ladybugs to your outdoor garden. Wait until a heavy dew or water your garden in the early morning hours. Release the ladybugs onto the wet plants where they will linger because of the moisture and coolness of the day giving them a chance to discover prey such as spider mites and aphids.
- Spider mites generally live on the undersides of leaves so be sure to spray that area well with an insecticidal soap.