Cool, Wet April Means Good for Pests, Bad for their Enemies

It is rare to experience back to back armyworm outbreak years.  This is usually because the natural enemies (particularly parasites and entomopathogens) build up in an outbreak year and are in good supply the following year to keep up with the armyworm.  However, armyworm outbreaks do tend to occur after a cool, wet April since those conditions are detrimental to these natural enemies. April was just that, cool and wet.  Plan to scout for armyworm in forages and wheat these early weeks of May to stay ahead of any problems.  Once they get to be an inch or larger, it starts to get difficult to control them.  More information on armyworm scouting can be found at: http://www.omafra.gov.on.ca/english/crops/pub811/13cereal.htm#tarmyworm

This same cool, wet weather can impact the natural enemies of other pests too.  Cereal leaf beetle and alfalfa weevil are two that can get out of hand after a cool wet spring.  Scout now for these two pests, particularly in fields with a history of infestations.  Information on cereal leaf beetle scouting can be found at: http://www.omafra.gov.on.ca/english/crops/pub811/13cereal.htm#clbeetle and alfalfa weevil at: http://www.omafra.gov.on.ca/english/crops/pub811/13forage.htm