Blog: The Wheat Sheaf

Potential Insect Pests to Watch for in 2016

Be ever vigilant for the six legged villains! The likely, crop eating, insects that can damage yields and affect profitability. Here is the list of the most likely perpetrators.

Cutworms and wireworms attack cereals, pulses and oilseeds early in the spring. Wireworms tend to be a problem in fields that have recently been taken out of grass or grass hay. Feeding occurs underground, on the roots and newly germinated seeds. They are usually visible as bare patches that cannot be explained by other reasons. Cutworms feed both above and below ground, depending on species. Signs of feeding are cut off plants on the ground or missing patches. Check the edges of these bare patches for the worms. Wireworms are best controlled with an insecticidal seed treatment and cutworms with an evening application of insecticide.

Grasshoppers are a likely suspect to damage crops in dry years. A rule of thumb is that they start to emerge when the lilacs bloom. They emerge from undisturbed soils, usually in early June but mid-May, this year. You’ll find them first on headlands and roadsides. The best time to control them is when they are small and in the first three instars (larval stages). They do not move around much when they are small. Once they become adults however, they are much harder to control as they can fly in from adjoining fields. Grasshoppers will eat any green crop.

Wheat midge show up when the wheat heads are emerging from the boot. It is best to check your fields in the evening, on a calm night. Wheat midge are weak fliers and spend most of their time close to the ground. They lay eggs in the wheat flowers where the larval damage the developing kernels. Egg laying occurs from head emergence until the wheat head flowers, which can be a mere matter of days. Treatment may be required if there is one midge per four or five heads or more when conditions are calm in the evening.

Cereal leaf beetles feed on wheat, barley and oats. They have been found in central Alberta. The larvae appear slug-like and damage leaves by rasping on the leaf surface. Be careful when deciding to spray for them as their predators and parasites are also with them and insecticide spraying is rarely needed.  

Regardless of the pest, the important thing is to be vigilant and check your fields on a regular basis. Check Alberta Agriculture’s pest maps for possible problem areas. Know the thresholds and use appropriate control measures as needed. Prevent unexpected losses by keeping informed.

Important Links:

Alberta Insect Pest Monitoring Network

Prairie Pest Monitoring Network

Wheat Midge Forecast and Map

Grasshopper Forecast and Map

Wheat Stem Sawfly Forecast and Map




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