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

Corn Rootworm Product Efficacy Trials, UW-Madison Entomology 2003-2005

By WCM Staff on 1/19/2006 3:00 AM

The impact of corn rootworm larval feeding on corn is evaluated each growing season in replicated small plot trials at the Arlington Agricultural Research Station using the Iowa State University 0 to 3 Node-Injury scale (Oleson et al. 2005). The current article summarizes root-rating results for three years, 2003-2005.

European Corn Borer Summer Moth Flights Have Peaked, Prepare for 2nd Generation

By WCM Staff on 8/4/2005 11:43 AM

For those who may not have caught last week’s (July 29) issue of the WI DATCP Wisconsin Pest Bulletin, please be aware that emergence of the summer flight of European corn borer moths has peaked in parts of Wisconsin.

Adult Corn Rootworm Sampling and Economic Thresholds in Continuous Corn

By WCM Staff on 8/4/2005 11:29 AM

Damage to corn roots by corn rootworm larvae in continuous corn fields during the 2006 growing season will depend on adult corn rootworm beetle populations in corn fields over the next 5 to 6 weeks. The only way to determine whether a field is likely to have an economic rootworm infestation next year is to scout for adults this August-September.

Advanced Armyworm and Outbreak Pockets in Western Wisconsin

By WCM Staff on 7/28/2005 12:31 PM

Corn fields in western and west central Wisconsin are exhibiting advanced armyworm larval stages and extreme corn leaf feeding to the midrib. Some of the reports, as detailed below, are related to grassy weed presence and/or later than optimal grassy weed control. However, more extensive field areas are being defoliated due to heavy populations, independent of weed management issues.

Spider Mites – Threshold Overview, Effects of Rain

By WCM Staff on 7/28/2005 12:08 PM

Spider mites continue to be present on soybeans in Wisconsin. The main questions coming in by phone and at field days over the last week are “What is the threshold for two-spotted spider mite?” and “How will the recent strong storms affect mite populations?”.

Critical to Watch Soybean Aphids as Temperatures Cool

By WCM Staff on 7/28/2005 11:22 AM

As reported in the July 21st issue of Wisconsin Crop Manager, soybean aphids continue to warrant close monitoring. By mid-July fields exceeded threshold in many southern WI counties and received timely insecticide application based on populations in excess of 250 aphids per plant average.

Research Brief: 0 to 3 Node-Injury Scale for Corn Rootworm Rating

By WCM Staff on 7/7/2005 2:03 PM

A recent article published in the February 2005 issue of Journal of Economic Entomology titled “Node-Injury Scale to Evaluate Root Injury by Corn Rootworms (Coleoptera: Chrysomelidae)” (Oleson et al. 2005) provides new and improved guidance for the annual corn root rating task.

Time Approaching to Evaluate Corn Roots for Injury by Corn Rootworms

By WCM Staff on 7/7/2005 12:57 PM

Over the next couple of weeks of July, we enter the crop season window during which to evaluate corn root injury by corn rootworms. We are planning to dig roots, soak and then wash the soil away with a high pressure hose stream, and quantify root injury in our UW Madison Entomology research trials, insecticide efficacy program, and on-farm studies between the dates of July 18th and July 25th.

Soybean Aphids and High Temperatures

By WCM Staff on 6/23/2005 12:44 PM

Much of Wisconsin is forecasted to experience high temperatures. As we are all in the field experiencing temperatures in the upper 80s and approaching 90s or higher heat index ratings, how will this affect population growth of the soybean aphid?

Guest Article Feature: Planning for the 2005 Soybean Aphid Population

By WCM Staff on 5/26/2005 1:30 PM

With soybean planting well underway for 2005 there is a lot of concern about potential pest problems, both rust and aphids this year. Following a year in which the soybean aphid was widely distributed in the Midwest but rarely common enough to generate concern, the question is what about 2005?

Field Reports: Dingy Cutworm in Corn, Look for Black Cutworm Cutting

By WCM Staff on 5/26/2005 1:21 PM

Several reports have come in this week on Dingy cutworm larvae in seedling corn fields. Several reports have come in this week on Dingy cutworm larvae in seedling corn fields. These corn fields are just emerging, or up to the first true leaf stage. Common to all these consultant calls is that the fields of concern are of sandy soil type.

What kind of Bean Leaf Beetle Activity are we expecting as Soybean Seedlings Emerge?

By WCM Staff on 5/19/2005 3:20 PM

Depending on temperature, peak activity for overwintered bean leaf beetle will continue throughout the month of May. A window of vulnerability exists for early planted (late April to early May) soybeans. Field scouting is critical for the rest of May as seedling soybeans are present at the same time overwintered bean leaf beetles are feeding and laying eggs.

Prepare to Monitor Alfalfa Stands for Alfalfa Weevil Larvae

By WCM Staff on 4/28/2005 11:10 AM

Alfalfa weevils overwinter as adults, becoming active with the first warm days of spring in which they migrate from plant debris, woodlots, ditchbanks, etc. into alfalfa stands to lay eggs. Most eggs are deposited in stems of the growing alfalfa. By using degree days (accumulated above a base 48F), growers and crop advisors can monitor fields for alfalfa weevil activity.

Stewart’s Wilt outlook in WI corn for 2005 – and ID tips on springtail versus corn flea beetle

By WCM Staff on 4/21/2005 4:01 PM

Corn flea beetle can vector Stewart’s bacterial wilt of corn, and is of concern in susceptible sweet corn varieties and susceptible dent corn inbred seed production fields if 1) corn flea beetles have a high overwintering survival rate 2) Stewart’s wilt bacteria is available for the corn flea beetle to pick up and spread.