NDSU Crop and Pest Report - May 16, 2013
Entomology
Corn - Spider Mites and Corn Leaf Aphids (7/19/12)
Scout for spider mites and corn leaf aphids in corn. Reports of corn leaf aphids have been reported in Benson and Cavalier Counties, and spider mites in Cass County. These corn insect pests also have been reported in neighboring states (South Dakota, Minnesota, Iowa).
Grasshoppers Increasing (7/12/12)
With the hot and dry weather, grasshopper populations are increasing, especially in western North Dakota. Wheat fields in McKenzie County are reporting large numbers of grasshoppers resting on wheat heads.
White Heads - Wheat Stem Maggot (7/12/12)
White empty heads are being observed in cereal grain fields. These were likely caused by wheat stem maggot. A single maggot (larva) is responsible for causing the white head and can be found inside the stem just above the last node.
Scout for Banded Sunflower Moth (7/12/12)
Banded sunflower moths and sunflower moths are being captured at higher numbers in pheromone traps at Mapleton, Cass County.
Continue to Scout for Soybean Aphids and Spider Mites (7/12/12)
Early-planted soybean is now reaching the R1 growth stage in southeastern North Dakota. Although soybean aphids were detected rather early in eastern North Dakota, numbers remain low.
Too Hot for Soybean Aphids (7/5/12)
Soybean aphids continue to be stagnant or low (see IPM map) due to abundance of beneficial enemies in fields and hot weather (>90 F), which slow population growth to nil.
Cereal Aphids Increasing (7/5/12)
Pockets of increasing populations of cereal aphids are starting to show up in North Dakota; however, most of the wheat and barley are passed the susceptible stages (prior to the completion of heading) for yield loss from cereal aphids (see IPM maps below).
Alfalfa Weevils Past Feeding Injury Period (7/5/12)
Alfalfa weevil larvae are at the end of their feeding period (595 DD) in North Dakota (see DD map below).
Potato Psyllids Detected in Potatoes (7/5/12)
Adult potato pysllids have been detected in North Dakota’s potatoes, about one month earlier than 2011 (Source: N. Gumestad, Dept. Plant Pathology, NDSU).
Sunflower Moth in ND (7/5/12)
The first sunflower moths of the season were captured in pheromone traps located in Walsh, Ward and McLean County, ND.
Aphids in Canola (6/28/12)
Aphids have been observed on canola near Minot in Ward County, Underwood in McLean County, McHenry County and northeast Hettinger County.
Wheat Midge Update (6/28/12)
The distribution map (shown) depicts the 2012 forecast for populations of wheat midge from the surveyed areas of North Dakota.
Banded Sunflower Moth Emerging (6/28/12)
The first banded sunflower moth of the season was captured in a pheromone trap located at Mapleton, Cass County, ND. This is about two weeks earlier than last year.
Sunflower Moth in Safflower - SD (6/28/12)
Although safflower is relatively insect-free, larvae of sunflower moth were observed in safflower in central South Dakota near Hayes in Stanley County.
Scout for Foliage-Feeding Caterpillars (6/21/12)
We have received some reports of defoliation by thistle caterpillars in soybeans in Pembina County and in sunflowers in Ward County.
Scout for Potato Leafhoppers (6/21/12)
Potato leafhoppers are present in potato and other field crops in North Dakota, and have been reported in other states (Minnesota, Nebraska, Iowa).
Degree Day Update - Leafy Spurge Flea Beetle (6/21/12)
Most of the state (except the northern tier) can start collecting leafy spurge flea beetles (1,200 and 1,600 AGDD) for distribution to new field sites (Source: sunflower GDD model from NDAWN).
Soybean Aphids (6/14/12)
Soybean aphids have been reported in extremely low numbers from a few locations in eastern North Dakota.
Scout for Black Cutworm in Corn (6/14/12)
Black cutworms are migratory moths that arrived in North Dakota early this year. Larvae (worms) and feeding damage in corn have been observed in Cass County near Casselton, Arthur and Page.
Cereal Aphids Increasing in Spring Wheat (6/14/12)
Spring wheat is advancing quickly with 74% jointed, 30% boot and 10% headed (Source: North Dakota Crop, Livestock and Weather Report, USDA NASS, June 11, 2012).
