Scout wheat fields for brown wheat mite

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

Brown wheat mites (BWM) have been confirmed in several sites in western South Dakota. 

These spider mites belong to the family Tetranychidae, the same mite family as the two-spotted spider mites. They also do well in dry conditions, says Ada Szczepaniec
assistant professor, SDSU Extension entomologist.

"The lack of moisture likely contributed to outbreaks of these mites on wheat. BWM populations will decline rapidly if it rains; another good reason to hope for some moisture to aid the wheat crop this year," Szczepaniec said.

BWM are small (1/16 of an inch), round, dark-colored mites with long pair of front legs. Szczepaniec explains that BWM can attack several crops but they can be particularly troublesome on small grains planted in the fall.

"These mites feed on the plants during the day, and spend the nights in the soil at the base of wheat plants. This is also where the mites lay their eggs, on particles of soil at the base of the plants," she said.

These mites prefer arid conditions but do not do well in very hot temperatures, and they will enter diapause (i.e., inactive, 'resting' period) during the summer. The mites over-summer as white eggs in the soil; they will hatch when temperature and moisture levels are adequate, and females from that generation will lay red eggs.

"This is relevant because if most of the red eggs are already hatched and white eggs are present, this indicates that the population is in natural decline and chemical treatment may not be economically sound. If, on the other hand, most of the red eggs are not hatched, the mites are likely to keep increasing in numbers. A good 10X hand lens will be sufficient to see the eggs," Szczepaniec said.

Scouting for these pests is recommended during mid-afternoons on calm days. Because heavy BWM infestations are rare, Szczepaniec says there is not a well-defined threshold for management.

Chemical control is recommended when at least several hundred mites per row-foot in the early spring. Szczepaniec says this decision should be made cautiously because these mites are associated with drought-stressed plants.

"If it rains, the BWM populations will decline; if it does not, the crop yield may be already affected by the drought and managing BWM will not affect it," she said.

Taking note of the eggs may be helpful in management decisions as well: if white eggs are present and most of the red eggs have hatched, BWM populations are in decline and treatment is not recommended. If chemical control is deemed necessary, products containing dimethoate or chlorpyrifos are recommended.


Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...


Comments (0) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left


Kinze 1500 Grain Cart

The Kinze 1500 Grain Cart is engineered for speed and reliability required of custom harvesters. Load up to 1500 bushels ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form