Little critters will be scouring the soil looking for something juicy to eat. Below is a brief summary of what to watch out for. For more detailed information on thresholds, scouting and lifecycle, Publication 811: Agronomy Guide and Publication 812: Field Crop Protection Guide, have great information.

Wireworms – Feed on roots, seeds and germinating corn seedlings. They have hard, copper-brown coloured bodies and range from 7 – 35 mm long. Wireworms are more prevalent in sandy soils, knolls and in a year following sod or high, grassy weed pressure. To manage wireworms, follow a good rotation and control grassy weeds in crops before corn.

European Chafer – There are many types of grubs that can feed on field crops. European Chafer is the most common. Grubs feed on roots and can cause stunting and death.  Feeding damage normally occurs in April to May. Sandy knolls can be a hot spot. There are no rescue treatments for grubs. Tillage can bring the grubs to the surface where they will be exposed to weather and natural enemies. If you have an extreme case of grubs, it is best to plant soybeans instead of corn.

Black Cutworm – There are reports of record flights of black cutworm moths by Purdue University. Cutworms are grayish-black, with no distinct markings and hide in the soil during the day. Small larvae can cause plants to wilt and larger larvae will cut the corn off at the soil. Look near cut or wilted plants and under soil clods to find larvae. Cutworms do not overwinter in Ontario, but are carried in on winds from the south. Fields along Lake Erie can be more at risk. The Genuity® SmartStax® trait provides protection for many above and below ground insects, including Black Cutworm.

Slugs – Slug feeding causes a ragged, skeletonized appearance on leaves and you will often see a shiny slime trail on soil or leaves. Slugs prefer cool, wet weather and can also feed on the germinating seed.

Seedcorn Maggot – Small, headless, legless larvae that feed on germinating seeds.  Seedcorn Maggots are usually a concern in cool, wet springs where germination is slow. Reduced stands or slow emergence are some symptoms of feeding.

Maizex uses Acceleron® seed treatment, which provides protection from early season pests such as wireworm, seedcorn maggot, white grub and black cutworm. It is always a good idea to walk fields after planting so you can keep a record of what pests are in each field for future reference.

Laura Johnston, CCA-ON, Maizex Seeds Yield Specialist, West Elgin County
Twitter: @lmjohnston8