Brown wheat mite (Kansas Wheat)

Scouting time

Affected plants have finely mottled leaves that appear yellowed or bronzed at a distance but lack the webbing produced by the Banks grass mite. Activity is highest in late fall and early spring, with populations usually peaking around mid-April. Eggs are laid in the soil and those produced in winter are brick red and lack the waxy coating of summer eggs. Outbreak potential is high because all adults are female, and each can produce 70 to 90 winter eggs in a three-week period. Later in spring, females begin laying small, white, oversummering eggs at the base of infested plants. These eggs do not hatch until fall. Damaging populations are usually limited to continuous wheat fields or those where volunteer wheat was present during the previous spring. Mite populations can be quickly reduced by heavy rains.

Sampling method

They are usually most visible on foliage during the early afternoon on warm days, but populations can be difficult to assess as mites quickly drop off plants.

Thresholds

The economic threshold is not well defined, but is estimated to be at least several hundred mites per foot of row in early spring. Concern is greater if plants are stressed or poorly tillered. This is a dry weather pest and treatment response often depends on subsequent rainfall to assist plant recovery. Treatments applied after populations begin natural decline in mid or late April are of no value.

Chemical control

Brown Wheat Mite Management Options

Insecticide

 Rate

Chlorpyrifos (Numerous products)

 Check label, but generally 0.5 to 1 pint/acre

Chlorpyrifos plus gamma-cyhalothrin (Cobalt Advanced)

 6 to 13 fl. oz./acre

Dimethoate (Dimate and others, formerly Cygon)

 49 WSB is 1 lb./acre

 

Non-chemical controls

None listed.

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Disclaimers

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