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AgAlerts 2001 From Griggs County
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Issue # 2, May 10, 2001
This insect has not been a problem over the last few years due to earlier planting dates in regards to Growing Degree Days (DD) determining midge emergence. The result of this is the low numbers of wheat midge larvae that were found last fall in the annual Wheat Midge Survey. In Griggs Steele, Barnes Foster and Eddy counties, midge larvae per square meter were found to be in the 0-200 range with several fields surveyed having no midge in the samples. The highest recorded midge samples were north of Devil Lake and west of Minot. The only concern at this time is the planting window we are in. HRSW planted PRIOR to accumulating 200 DD (based on 40 degrees) will head before wheat midge emerge (Safe). HRSW planted FROM 200 to 600 DD will be heading at the time wheat midge are emerging (At Risk). HRSW planted AFTER 600 DD will head after peak emergence and should be at low risk to midge infestation (higher risk of frost, however). As of May 10th, the Dazey NDAWN weather station is recording 297 DD and the McHenry station is recording 278 DD. The good news is the low numbers found last fall. This does not mean you don't need to monitor for this insect at heading time, the chance of a severe out break is reduced.
NDAWN currently consists of 49 automatic weather stations, 42 distributed across North Dakota, 2 in eastern Montana and 5 in northwestern Minnesota. NDAWN stations monitor weather conditions continuously and provide hourly and daily summaries. Data are retrieved daily via telephone modem by personnel from the High Plains Climate Center (HPCC), Lincoln, NE. Following quality control procedures, data are archived and transferred to the NDSU Extension Network (ExtNet) computer system. Through ExtNet, past and current (yesterday's data today) weather data are available in a variety of formats. Data are also available through the Regional Weather Information Center, University of North Dakota.
Measured and calculated variables include:
Air Pressure
Air Temperature
Dew Point Temperature
Degree Days (Growing, Heating, Cooling, Insect)
Potential Evapotranspiration and Crop Water Use
Rainfall
Relative Humidity
Soil Temperature
Solar Radiation
Wind Speed and Direction
To access the NDAWN web site, use the following address: http://www.ext.nodak.edu/weather/ndawn/
Those fortunate
to have planted canola, might want to check emerging fields for crucifer flea
beetles. We had one report of minor feeding this week. The adult
flea beetles are active and continually emerging for a three-week period in the
spring. As a result, field monitoring is critical for untreated or
partially protected fields, or fields with a history of high flea beetle
populations. Hot, sunny weather produces high feeding activity, while
cool, damp weather slows feeding an favors crop growth. In some instances,
crucifer flea beetles can move quickly and infest large fields by flying; in
other instances beeles invade slowly and creep moving from plant to plant in a
field.
Foliar applications are only recommended when an economic
threshold of 25% damaged plants is reached. When flea beetle populations
are high, more than one application may be necessary. Registered products
for North Dakota for foliar applications include: Capture 2 EC, Ethyl-methyl parathion 6-3,
and Methyl parathion 8EC. For more information go to the NDSU 2001 Field
Crop Insect Management Guide for
Canola
and Mustard Insects.
With the amount
of water in the region, it could be a good year for mosquitoes. Now is the
time to try and reduce the problem with early control measures. Where
standing water is a problem around the home or farmstead, one of the recommended
treatment programs is the use of Bacillus thuringiensis var.
israeliensis (B.t.i.). Products include: Aquabac 200 G, 1.2% AS, Bactimos 10% Briquets, Mosquito
Dunks 10% Briquet, Teknar HP-D 1.6%
and Vectobac 0.2% CG, 0.2% G, 12% AS.
A bacterial larvacide that is non-toxic and will not harm non- target, beneficial organisms. Higher rates are recommended in water with high organic content (e.g., sewage disposal systems, waste lagoons). Pretreatment is recommended when larval populations are high, aquatic vegetation is dense, or the water is highly polluted with organic material.
There are other products on the market for larval control and can be found in
the NDSU Bulletin E-72, "Mosquitoe
Management".
Please Contact Our Office For Additional Information
E-mail: griggs@ndsuext.nodak.edu
Go to the 2001 AgAlert Index Page