Wisconsin Crop Manager newsletter

Author:	WCM Staff	Created:	4/21/2006 12:13 PM
Whats bugging you. Articles concerning insects on field crops in Wisconsin

Do Not Let Western Bean Cutworm Catch You Off-Guard

By WCM Staff on 7/30/2009 9:33 AM

Wisconsin looks to be in for our highest Western Bean Cutworm pressure yet. Don’t let WBC larvae in field and processing sweet corn ears catch you off guard in August and September. Scouting now is critical to determine field infestation and prevent populations from reaching economic injury level.

Western Bean Cutworm Moths Flying, Scout Field and Sweet Corn

By WCM Staff on 7/23/2009 9:27 AM

WBC is a late season corn ear pest. WBC has one generation per year, with six or seven larval stages, and overwinters as a full-grown larva, inside a soil chamber. Spring development begins when temperatures exceed 50°F. Larvae pupate in May and moths begin to emerge from soil chambers in early July. Multiple WBC larvae can infest one ear and cause yield loss and impact quality of grain (damaged, decaying kernels, secondary pathogen infection).

Armyworms in Wheat in NE Wisconsin

By WCM Staff on 7/17/2009 12:22 PM

Many thanks to Jeff Polenske and his colleagues of Polenske Agronomic Consulting, for alerting us to the potential for armyworm injury in the northeast part of the state. Currently they are finding significant numbers of large armyworm larvae in wheat. Very little head clipping at this time but harvest is still a ways off. Let’s take some time to review armyworm habits. Hopefully this will help you with scouting and making control recommendations.

Soybean Aphid Densities are Low, But Start Scouting Now

By WCM Staff on 7/9/2009 11:41 AM

Wisconsin soybeans have yet to see economic soybean aphid densities. Statewide, field averages continue to be well below the economic threshold of 250 aphids/plant. However, soybean aphids are present in fields and the time to begin scouting is now.

Troubleshooting Hints for Common Early Season Insects (and slugs) in Corn

By WCM Staff on 6/4/2009 1:22 PM

Troubleshooting calls on seedling corn are likely to be starting if they haven’t already. Once you have narrowed the cause down to insect there are still a number of choices you will need to make for an accurate diagnosis. Troubleshooting would be much easier if all we dealt with was classic, text book symptoms but that is rarely the case. Of course finding the insect will make the diagnosis easier. If not, here are some helpful hints.

True Armyworms

By WCM Staff on 5/28/2009 9:32 AM

True Armyworm is yet another insect to keep on your radar over the next few weeks. There hasn’t been any report of damage in Wisconsin or to the states to our south but the WDATCP has reported sporadic, low intensity flights in their blacklight trap network.

Black Cutworm

By WCM Staff on 5/19/2009 2:26 PM

WDATCP staff recently reported “light to moderate” black cutworm pheromone trap catches and suggested that cutting of seedling corn could occur by late May in southern Wisconsin.

Alfalfa Weevil

By WCM Staff on 5/19/2009 2:12 PM

Southern Wisconsin has now accumulated 300 weevil degree days (or soon will have) which is when eggs are starting to hatch and scouting is recommended. To get a feel for what may be happening in your area, spot check alfalfa fields for weevil damage in areas that warm up quicker (eg. south facing slopes, sandy areas, etc.). Look for tiny pinhole feeding in the upper leaves. The economic threshold for first crop alfalfa is when 40% or more of the stems have leaf feeding. Read more for pest ID.

Bean Leaf Beetles - in WI - in 2009?

By WCM Staff on 5/14/2009 1:05 PM

Although the early indications are for a light overwintering population, there is still a need to spot check early emerging soybean fields.

Diagnosing Western Bean Cutworm Larvae in Corn Ears

By WCM Staff on 9/18/2008 5:30 PM

This article summarizes WBC larvae reports from around the state; provides diagnostic pictures of WBC larvae and damage; discusses how to distinguish WBC larvae and feeding from corn earworm and/or European corn borer; and summarizes economic impact and yield-loss relationship data for WBC in field corn.

Soybean Aphid Update for Late August 2008

By WCM Staff on 8/21/2008 4:38 PM

Soybean aphid populations have not yet “crashed”. As of the week of August 18th, soybean aphid populations have continued to flourish and increase beyond threshold in some areas of Wisconsin.

Western Bean Cutworm Reported - Monitor Field & Sweet Corn for Egg Masses and Small Larvae

By WCM Staff on 8/7/2008 12:41 PM

Western bean cutworm (WBC) moth flight, egg hatch and larval development underway in Wisconsin.

Section 18 for Coragen, for Corn Earworm, Sweet Corn

By WCM Staff on 7/24/2008 5:40 PM

On July 23rd, the U.S. EPA approved a Section 18 request by the Wisconsin Department of Agriculture Trade and Consumer Protection (WI DATCP) and UW Madison Entomology Department for the use of the insecticide, Coragen (DuPont), in the state of Wisconsin. Use of Coragen on sweet corn is targeted for late-planted sweet corn that is historically susceptible to migrating Corn Earworm (CEW) moths that cause considerable damage to sweet corn ears.

Soybean Aphid Increasing and Variable – Scout Fields Now

By WCM Staff on 7/24/2008 2:50 PM

This week soybean aphid populations have increased noticeably. That is a relative term in this case. In some areas such as Dodge and Sauk Counties, this increase is from near zero activity to field averages of 10 aphids/plant and 30-60 aphids/plant. In other areas however, West Central and East Central Wisconsin for example, higher populations are starting to be reported closer to Economic Threshold in a few fields.