Spider mites Reference Page

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Sugar beets Spider Mites Pest Alert Identification:

Spider mites are plant pests that are so small they are sometimes difficult to see without a magnifying glass. They are about 1/50" long, approximately the size of a grain of salt or slightly larger. They may be red, black or brown. Eggs or adults overwinter in bark crevices or in ground debris, emerging in early spring. The eggs hatch in 2-3 days, and the adult stage is reached in 7-10 days. The result is many generations and very large population increases each season.

Description of Damage

Mite damage is often not as serious as it looks. Plants can often tolerate extensive "stippling" as the yellow speckling is called, and distortion of foliage without being seriously harmed as long as the process of photosynthesis can still occur.

Integrated Spider Mites Management Information

Biology

Spider mites overwinter as adults. In spring they move to new growth and lay eggs on the undersides of leaves. Mites can be blown by wind, so colonization of a field often occurs in the direction of prevailing winds, or along features that disrupt air flow, such as tree lines. Eggs hatch in a few days and small mites begin to feed. The grow by molting, and if you look closely at a mite-infested leaf, you sometimes see the shed skins of immature mites. A leaf heavily infested with a mite colony will have eggs, young, adults, shed skins, and webbing.

Management

According to Sugar Beet Insect Pests by Ed Bechinski in the Pacific Northwest 2001 Insect Management Handbook page 137.