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Wet Weather Increases Risk For Fusarium Head Blight in Wheat, Irrigation May Mean Higher Risks 

Centreville, June 3, 2008:  Fusarium Head Blight (Wheat Head Scab) can be a serious disease of wheat.  The fungal pathogen thrives in conditions that provide saturated soils and wet foliage for the period 5-7 days before through the time of flowering.  Fields that were planted to corn and seed corn last year are considered to be the most at risk, because the crop residue can provide the inoculum for the disease.  Many of the wheat fields in St. Joseph and Kalamazoo Counties are at or are approaching flowering at this time.  If producers have irrigated in the last week, and the fields have received rainfall over the last 2-3 days, fields may be more at risk for developing the disease.  Many fields have been treated with fungicides to help prevent fusarium.  However, because of the dry conditions over the last several weeks, producers may have opted to see what infection periods develop with the weather.  With rainfall in the forecast for the few days, some producers may want to consider applying fungicides to protect the crop from scab.

The forecast is calling for much warmer temperatures and about 30-40% chance for precipitation during the next 48 hours.  MSU has been working with Penn State University to include weather stations in the MAWN system to predict the potential for Fusarium in your wheat fields.    Click here to visit the PSU Wheat Fusarium Head Blight Predictive Tool.    Click on a weather station location closest to you to get more specific weather information related to location.  MSU Field Crops Pathologist Diane Brown-Rytlewski has developed a nice fact sheet on Fusarium Control in wheat.  It is available on the web at:  Click here for information fungicides that can be used to help control Fusarium Wheat Head Blight.  

Asiatic Garden Beetle Larvae Have Moved Up In The Root Zone, Other Pest Updates 

Centreville, May 1, 2008:  Asiatic Garden Beetles (AGB) larvae feeding caught everyone by surprise in the 2007 growing season.  The larvae, which are white grubs similar to those of it's cousin, the Japanese Beetle, caused stand reductions in mainly commercial corn fields in several areas of St. Joseph County last year.  The St. Joseph County MSUE Ag Program was successful in developing a Project GREEEN Proposal to investigate the life cycle, control options and spread of this insect throughout southwest Michigan in 2008.  As a result, we have been monitoring many soybean stubble fields in St. Joseph County this spring for the presence of AGB larvae.  While many fields have low to moderate AGB Grub counts, we were able to find a couple of suitable locations to establish research plots to compare feeding injury on commercial corn with 2 soil insecticides, 2 levels of seed treatment to seed without insecticide protection.  For producers that had problems with stands last year and could not attribute the damage to Sand Hill Cranes, especially in southern or central St. Joseph County, we think that it may be prudent to include an insecticide treatment at planting time, or use insecticide treated seeds.  Keep in mind that genetic resistance built into rootworm resistant corn hybrids is not anticipated to help in controlling damage from white grubs.  During last year, the greatest damage from AGB larvae occurred on fields where commercial corn followed soybeans in the rotation.  The female AGB tended to lay their eggs in sandy or gravelly knolls in fields that were predominately sands or loamy sands.  Right now, the larvae are up near the soil surface, primarily feeding on chickweed and other winter annual weed species roots.  The larvae are about 1/2 to 5/8 of an inch in length or smaller.  Some fields have some larvae that are down 3-5 inches or lower in the profile.  There is also a good deal of variability in larvae size in the fields, with smaller larvae moving towards the soil surface.  In early observations, it appears that winter annual weeds may help the AGB larvae to gain sustenance until the crop is planted.  We will be following the growth and development of these insects over the growing season.

 Alfalfa Weevil, Cutworms can be found in St. Joseph County Fields. 

Centreville, May 05, 2008:  Alfalfa weevil larvae are beginning to become active in St. Joseph County in several fields.  MSU Field Crops Entomologist Dr. Chris DiFonzo spent this morning helping us to establish the AGB research sites, and walked through several fields with us this morning.  She noted that the alfalfa weevil larvae, while small, are beyond the first instar stage, and should be anticipated to respond to the warmer temperatures in the forecast.  The fields that we walked through are currently showing about 10-15% tip feeding, well below the treatment threshold of 40% tip feeding, so treatments are not currently warranted.  It does, mean, however, that producers should keep alfalfa weevil on their pest management radar screens and to continue to monitor fields during the busy planting season.  It does appear as thought the alfalfa crop was nipped by the very cold temperatures on the early morning hours of April 30th.  There are some signs of yellowing and whitening of the upper leaves, especially in the lower portions of fields.  With favorable growing conditions in the forecast, alfalfa should have the best opportunity to recover and begin solid growth.  Click here for more information on alfalfa weevils, their lifecycle, treatment thresholds and the best ways to control this pest. 

We also found a few black cutworm larvae while out digging for AGB in fields.  They were found in fields where winter annual weeds were prevalent.  The larvae were approximately 3/4 of an inch in length.  There were not a lot of cutworms present, but it is important to keep them in mind, especially on fields that have high levels of winter annual weeds that were present over the last 2-3 weeks.

Black Flies Confirmed (And Biting) in St. Joseph County. 

Centreville, May 08, 2008:  With St. Joseph County being know as Southwest Michigan's River Country, we would expect that most of any biting that was going on down near the rivers would be by fish.  Unfortunately, a "new" organism can be added to the list of things that may bite in our area.  Several people reported being bitten by  small, gnat like insects that caused bleeding at the site, and subsequent pain and swelling.  After examining one of the offending insects under the stereoscope at the office, we were able to confirm that the culprit was a black fly.  Black flies are common in the northern portions of the state, and up into many parts of the northern US and especially Canada.  They can be significant pests, especially in areas where they occur in large swarms.  The black flies larvae are aquatic creatures, which require moving water in rivers, streams and creeks to be able to survive.  The female flies lay their eggs in swiftly flowing bodies of water.  The larvae hatch and attach themselves to aquatic plants, twigs or stones on the bed of the river or stream.  The larvae pupate and emerge as adults at varying lengths of time, depending upon water temperature. 

Black flies often swarm around their victim's heads because they are strongly drawn to the carbon dioxide from their breath.  Bites are often along edges of exposed skin and along the hairline.  Reactions to black fly bites vary from person to person, but often include itching and swelling at the site of the bite.  They usually are more active at dusk and at dawn.

It is difficult to control black flies in yards.  Foggers can help, but only control the flies that are in the area at the time the insecticide is applied, and do not keep new flies from moving in once the application is completed.  In terms of personal protection, consider using an insect repellent that contains DEET (N,N-diethyl-m-toluamide).  Black flies also seem to be attracted to darker colored clothing rather than white or other light colors.  Nylon head nets have also been used by sportsmen when populations are extremely high. 

Like many aquatic insect species, black flies are are very sensitive to water quality in the streams.  MSU's Diagnostic Entomologist Howard Russell says that he has been receiving increasing numbers of calls over the last 5-6 year from resident of southern Michigan counties report being bitten by black flies.  Howard says he is not surprised that we have black flies in St. Joseph County.  He says that it is just a small drawback to the improving water quality that is being seen in Michigan's Rivers, Streams and Creeks.

For more information on Black Flies, you can visit the following web sites:         

http://www.extension.umn.edu/yardandgarden/ygbriefs/e601blackflies.html

http://ohioline.osu.edu/hyg-fact/2000/2167.html

http://www.geocities.com/orchike/blackflies.html - From an Ottawa Ontario Outdoor Club (Excellent Graphics)

For further Agricultural and Natural Resources Information/Assistance, contact the following Regional/District Agents: