Baute Bug Blog

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.

Okay..it is a busy week on the insect front.  Sorry..two posts in one day but I want to get the message out!

Bean leaf beetle adults are active in emerging soybean fields.  We are starting to see feeding damage in several fields in the southwestern counties.  These beetles have been waiting a while for soybeans to come up.  Fields not planted with Cruiser in areas that have been known to have overwintering adults (up to S. Huron and Wellington Counties) will need to be scouted to determine infestation levels.  For more information on bean leaf beetle scouting and thresholds, here are some helpful resources:

http://www.omafra.gov.on.ca/english/crops/pub811/4blb.htm

http://www.omafra.gov.on.ca/english/crops/pub812/3blb.htm

Cereal leaf beetles have also reached threshold in fields in the Aylmer and Delhi areas, which tells me that there could be more hot spots in that region (or others) that are being missed .  Scout wheat fields to see if any larvae or adults are present.  I realized the other day, a good way to describe the larvae is to look for a very dense muddy drop of water on the leaf.  If you look closer, it is probably cereal leaf beetle.

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