Spider mites are very small, less than 1mm and range in color and markings depending on the species. They use sucking mouth parts to puncture and drain cell structures in many types of plants. Classified as a sap-sucker.
Symptoms and Damage:
Spider mites get their name from the protective webbing they produce to shield their colony from predators. This webbing appears between the leaves and stems and is white in appearance. The upper surface of the leaves that the mites are attacking will develop yellow blotches and may fall prematurely.
Habitat and Life Cycle:
These damaging pests can be found mainly on the underside of leaves where they seek shelter from the elements and predators.
Spider mites reproduce very quickly and favor hot, dry conditions. Summer time can help spawn outbreak in farmers crops and orchards.
A single female spider mite is able to produce up to 20 eggs per day and can live an average of 2 to 4 weeks, meaning a single female mite can produce a colony of a million mites in one month.
Control and Prevention of Spider Mites
There are many benefits to avoiding chemicals when dealing with insect invaders. The harsh chemicals in some insecticides may cause more harm to an already injured plant not to mention the possible harmful effects to you or your loved ones.
✔– First choices for attempting insect control.
✔– Used when green don't solve the issue.
✔– Only use when blue options have failed and the plant cannot be discarded.
Prevention✔- Because spider mites enjoy a dry and hot environment don't give them one. Keep long weeds, grasses or other plants trimmed around house windows that have house plants in them. Carefully inspect all potential new house plants before bringing them home, this includes the leaves, soil and stems. Regular misting and inspection of susceptible plants is the best prevention.
Manual✔- If the mites are discovered early enough it may be possible to remove the affected area by placing a bag over it and cutting it off with a sharp sterile knife. Follow up by spraying the plant with a strong stream of water and watch carefully for any further signs of mites.
Organic✔- Tomato Leaf Spray, Garlic Oil Spray, or Neem Oil Spray have proven to be very effective although repeat applications will be necessary because the spider mite eggs are unaffected. Repeat every 10 - 14 days until no mites remain. People say that mixing 1 part of canola oil to 50 parts water and a few drops of liquid dish soap and spraying the tops and bottoms of leaves works well.
Biological✔- Many predators exist which feed on mites including other mites are available for purchase to the home gardener. These have proven highly effective as most mite predators feed on all the life stages of spider mites including the eggs.
Chemical✔- Control and prevention of spider mites is difficult because of their accelerated growth and reproduction cycle. Chemicals specially designed for mites can be effective but mites will quickly develop a resistance to the chemicals used. It is recommended to apply insecticides/miticides once every 10 - 14 days to attack the vulnerable life stages of the insect.
More information on Spider Mites:
Wikipedia - http://en.wikipedia.org/wiki/Spider_mite
Spider Mite Fact Sheet - http://www.ext.colostate.edu/pubs/insect/05507.html
How to Manage Spider Mites - http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html