NDSU Crop and Pest Report - May 16, 2013
Entomology
Aster Leafhopper Threat to Canola (5/24/12)
Aster leafhoppers (Macrosteles quadrilineatus) that we are observing in wheat and barley could move into canola and vector aster yellows.
Degree Day Update for Alfalfa Weevil (5/24/12)
The alfalfa weevil DD accumulation as of May 21, 2012 is displayed in the map below (source: NDSU NDAWN – Applications – Insect Degree Days).
Sugarbeet Root Maggot Flies Emerging Early: Plan Post-Emergence Control Strategies Now (5/24/12)
The first sugarbeet root maggot (SBRM) flies detected by NDSU personnel in the 2012 growing season were found in a field south of St. Thomas, ND on May 11. However, activity levels have remained fairly low for several days thereafter.
Scout for Flea Beetles in Canola (5/17/12)
Populations of crucifer and striped flea beetles have increased this week in canola near Langdon. Canola planted in April is emerged but still in the seedling stage.
Scout for Alfalfa Weevil (5/17/12)
By using degree days (DD) with a base of 48 F, the life stages and development of alfalfa weevil can be predicted using the degree day table.
Continue to Scout for Cereal Aphids (5/17/12)
New reports of very low populations of cereal aphids are being observed in cereals in southeastern North Dakota.
Leafhoppers - A Case of Confused Identities (5/17/12)
What we commonly refer to as Aster leafhoppers (which have been observed in wheat and barley this season) have over the years been confused under a number of different scientific names (each of which represents a separate species).
Not all Yellows are Created Equal (5/17/12)
(or, more correctly, not all yellows have an equal creation…) Leafhopper populations are increasing in the northern RRV. Fields which held low numbers on Friday have significantly increased populations this week.
Cutworm Moths Flying - Scout Fields (5/10/12)
There have been many observations of cutworm moths (or miller moths) flying around lights of houses and farm sheds. Cutworms typically have one generation a year in North Dakota.
Cereal Aphids Observed in Red River Valley (5/10/12)
The first of the season cereal aphids have been observed on winter wheat near Hillsboro in Traill County. Currently, these populations are very low – only 1 aphid per 10 plants.
Aster Leafhoppers in Winter & Spring Wheat (5/3/12)
Aster leafhoppers, Macrosteles phytoplasma, were detected in wheat and alfalfa in southwest Minnesota and South Dakota last week.
Scout for Early Season Insects: Cutworms, Cereal Aphids & Flea Beetles (4/26/12)
Since insects are temperature-dependent for their development, it is not surprising that insects are emerging earlier than normal with the warm winter and early spring. Some insects are already starting to appear in our field crops. So, scouting is essential to look for any early season insect infestations. Here are some insect pests to watch out for and scouting tips.
Soybean Aphids Decreasing (8/25/11)
Most of the fields have decreasing populations of soybean aphids now. Shorter day lengths and the maturity of the soybeans have triggered aphids to develop wings and fly back to its overwintering host, buckthorn, or late-planted soybean fields. Bruce Potter of UMN Extension already found soybean aphids on buckthorn on August 15 in SW Minnesota.
Watch for Grasshoppers (8/25/11)
This time of year, adult grasshoppers are very mobile and start to fly around after cereal crops and other early season crops are harvested to find green crops. So, it is important to continue to scout for grasshoppers in late-season row crops, such as sunflower, corn, flax, etc.
What Are These White Butterflies Flying Around? (8/25/11)
I’ve received many calls and emails about all of the white butterflies flying around ditches, canola, and other areas and whether they are an insect pest. These butterflies belong to the insect family Pieridae and to the group called Sulphurs and Whites, which are usually white or yellow in color.
Protect our Honey Bees from Insecticide Poisoning When Spraying Flowering Crops (8/11/11)
Honey bees and native pollinators are a vital part of our agricultural food production. The value of bee pollination is estimated at 14.6 billion dollars in the U.S.! With the reduction in numbers of both domestic and wild bee colonies due to Colony Collapse Disorder and other diseases, the value of honey bees, native bees and pollination has increased. This increases the importance of protecting all bees including native pollinators from pesticide poisoning.
Bean Leaf Beetle in Soybeans (8/11/11)
Economic numbers of bean leaf beetles have been reported near the Woodworth area in Stutsman County. With more soybean acreage in North Dakota, bean leaf beetle populations have been slowly increasing over the past years.
Soybean Aphid Update (8/11/11)
Soybean aphids have increased above economic thresholds in several areas now. This year, each field is different and scouting is the only way to determine if your field is above the economic threshold (average of 250 aphids per plant and 80% incidence in the field).
Scout for Sunflower Moths (8/11/11)
Sunflower moths migrate into North Dakota from southern states and do not overwinter here. Because of the migratory nature of this insect, it is only an occasional pest in North Dakota, but can be a very damaging insect pest when it does reach North Dakota and populations are high.
What Insect Is This? (8/11/11)
I’ve received many calls about what insect this is? Since it is often attached to the leaf of wheat or soybean plants, is it sucking the sap and killing the plants? The answer is good news.
