Welcome to Huron Bay Co-Operative Inc.

Be Aware Western Bean Cutworm is in YOUR area:

Western Bean Cutworm (WBC) is a pest that is and has been discussed at grower meetings for the past two years. We want our growers to know that WBC is in our area and this year we are trapping moths and doing counts. In previous years we have seen damage in various fields but didn’t have any numbers from traps to substantiate the damage we are seeing. WBC feeds on the ear of a corn plant. The adult moths lay their eggs on the leaves of the corn plant when the corn is at pre-tassel up until pollination has been completed. The WBC larvae feed on the green silk and move to the cob by eating from the outside of the husk into the kernels. These larvae can also move from plant to plant within a field. There is only 1 generation of larvae per year which is beneficial in our ability to scout and monitor these pests. These pests do not overwinter in fields and they fly in every year.

In the Markdale and Dundalk area we had 5 traps set up to monitor the activity & flight patterns of the WBC moths. Our traps were located in Meaford, Ravenna, Markdale, Swinton Park and Corbetton. These traps help us to monitor the peak flight times of the moths to better determine when scouting needs to be conducted and when peak egg laying will probably occur. When we are scouting for the egg masses of the WBC moths we scout 100 plants within the field. The threshold for spraying WBC is a cumulative count and occurs when there has been an accumulation of 5% of the plants with egg masses or small larvae found. Yield loss from WBC can be extensive as 1 WBC larva/ear has been estimated to reduce the yield by 15 bu/ac with yield being reduced by up to 40% if conditions are right. WBC can also lead to increased mycotoxins development within those ears of corn.

In 2019 our traps determined that peak flight of the moths occurred between August 12th and August 27th which is later than previous years which can be attributed to the late spring and the later taselling of the corn crop. Despite scouting our fields every week we were unable to find any egg masses in our fields. This meant that we did not spray any fields with insecticides for WBC. Our hot spot for moths was Ravenna followed by Meaford. The Markdale trap stayed significantly lower than our other traps in the area. Below is a chart and graph of our trap counts from our 5 trap locations.


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