Twospotted Spider Mite, Tetranychus urticae
(Acari: Tetranychidae)

The twospotted spider mite is considered to be the most common pest mite and is found throughout the United States. It is usually greenish-yellow in color with two dark spots near the back, but some may be orange-red in color. The first nymphal stage has three pairs of legs while subsequent stages have four pairs of legs. The life cycle is usually completed within seven days, but may take up to twenty days depending on temperatures. The adult female lives two to four weeks. Females overwinter in ground litter or under the bark of trees and shrubs. A hand lens (15X) can be used to identify the twospotted spider mite.

Damage can be intensified because of the overlap of generations. The presence of spider mites results in webbing on leaves, and stippling and curling of leaves. Complete defoliation may occur if spider mites are left uncontrolled. Plants should be inspected weekly for spider mite damage. A number of identified predators can provide sufficient control under some conditions. Miticides must be used sparingly due to the ability of the twospotted spider mite to develop resistance. Insecticidal oils and sulfur are commonly used to manage mite populations in greenhouses. They thrive under drought conditions so frequent overhead watering may help to suppress mite populations.

Images

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Twospotted spider mite, Tetranychus urticae, on webbing.
(Photographer: J. Castner, University of Florida)

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Twospotted spider mite, Tetranychus urticae.
(Photographer: J. Castner, University of Florida)

Click to access Display and Print quality images.


Twospotted spider mite, Tetranychus urticae.
(Photographer: J. Castner, University of Florida)

Click to access Display and Print quality images.


Twospotted spider mite, Tetranychus urticae, webbing on
strawberry leaves.
(Photographer: L. Buss, University of Florida)

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