Baute Bug Blog

It was a busy weekend for pest activity.

Flea beetles in canola continue to be a problem in some areas of the province, particularly Owen Sound, New Liskeard and Meaford.   This hot weather is ideal for them to get ahead of the crop.  Scout frequently to determine if thresholds have been reached. The Ontario Canola Growers’ blog has photos to show you what 25% feeding damage looks like. Once the crop is beyond the 4 leaf stage, it can usually grow ahead of the feeding activity.  See the Field Crop Protection Guide for foliar recommendations.  If using Matador, apply it early in the morning or late in the evening after the heat of the day as spraying above 25C temps can lessen the products effectiveness.

Cereal leaf beetles are in very high numbers in the Clinton area.  Leanne Freitag (Cargill) informed me that eggs they were monitoring last week have hatched and they have found a field that had populations as high as 10-15 per plant in part of the field.  One adult or larvae per plant is the threshold.  Protecting the flag leaf is most important.  Scout frequently to determine if they are present and stay ahead of any feeding activity.  Spray timing may or may not coincide with Fusarium control.  Don’t wait to control CL B for more than a few days if thresholds are already reached and feeding on the flag leaf has started.  More info on thresholds and products is available in the Agronomy Guide for Field Crops and the Field Crop Protection Guide.

True Armyworm eggs have been spotted on wheat in the Chatham area by Joe Tomecek.  No reports of larvae or damage have come in but lets stay alert and make sure that armyworm does not get ahead of us.   Wheat needs to be scouting every 3-4 days to stay ahead of both CLB and true armyworm activity.

It is a strange season.  Things that shouldn’t be happening yet are and it is really messing us all up in terms of catching things in time before they become a problem.

I just had a call from Laura Neubrand that she has found true armyworm in a late planted wheat field near Exeter that has 3 to 4 larvae per square foot!  Larvae are anywhere from 1 inch or smaller.  There is at least 30 more days before harvest so this field can still be saved.  But other fields in the area may not be as lucky.  Most products have 21 to 28 days to harvest intervals with the exception of 1 that has a 14 days to harvest interval.  So fields should be checked at least once before it is too late.  Best at early evening/night to actually see the larvae.  Seperate the plants to look down along the ground for any activity or frass.  4 larvae per square foot that are an inch or smaller is threshold.

The first report of spraying for armyworm in sweet corn in Essex County came in today. We are not sure how heavy of infestation to expect in other fields but wheat and newly emerging corn fields should be scouted in Essex, Chatham-Kent, Lambton, Elgin and Middlesex counties asap.  Armyworm reports from Essex tend to give us a few days heads-up to catch any infestations in the neighbouring counties.  But other counties in southwestern Ontario should be scouted in the next 7 days to 10 days to determine if armyworm is present there.

A CropPest Newsletter article will go out later this week with details on scouting and management strategies. You can also find information in the Agronomy Guide for Field Crops and past CropPest articles (links provided below)

http://www.omafra.gov.on.ca/english/crops/pub811/3taw.htm

http://www.omafra.gov.on.ca/english/crops/field/news/croppest/2008/05cpo08.htm

Alfalfa Weevil – We are starting to see a lot more alfalfa weevil larvae in the fields we are scouting.  Many fields in southwestern Ontario are ready or close to being ready to be cut.  I know you are busy trying to get everything planted finally, but I encourage guys to get out and cut the hay (if field is ready) to reduce the risk of injury from alfalfa weevil larvae.  If fields are not fit or ready to cut, you’ll need to scout and determine if the larvae are reaching threshold.  Again, cutting is the first choice for management if possible, if it is not, then spray at threshold.

Armyworm – It was around this time last year we started to see armyworm larvae appear in the fields.  We did catch a few moths in April and with all of the storm fronts that continued to come our way, there could have been more blown into Ontario.  Scout both the borders and randomly within wheat fields.  And soon to emerge corn fields are at risk too.  There were so many fields with weeds that didn’t get sprayed until now that were ideal for the moths to lay their eggs on.   Larvae could have survived on those weeds until the crop pops up out of the ground.  And they will be bigger (and harder to kill) when they do move over to the crop.

Let me know if you find any so we can get the word out!