2019 Wheat Midge Forecast

.

Wheat midge 2019 map

The wheat midge forecast for 2019 shows an overall low level of wheat midge across Alberta. There is very little risk of midge in the Peace Region, with the lowest level of midge found in the survey since the outbreak in 2013. Individual fields or small pockets of wheat midge may still exist so it is important to remain vigilant. The midge population in central Alberta east of Edmonton is also lower. In both the Peace and central Alberta this may be partially due the use of midge tolerant wheat. Wheat midge in both areas will remain a concern in individual fields, especially if there is late seeding and higher than average rainfall in the spring. Areas west and south of Edmonton have also seen individual fields with midge numbers at levels of concern as far south as Red Deer County.The population remains low in southern Alberta and the only midge found was associated with irrigated fields. Over the past several years the field to field variation has been very considerable throughout the province.

Individual fields throughout Alberta may have economic levels of midge.

PDF version of the wheat midge map

Each producer also needs to assess their risk based on indicators specific to their farm. Specifically, producers should pay attention to midge downgrading in their wheat samples and use this as an indication of midge risk in their fields.

This forecast is not intended to take the place of individual field monitoring. The forecast for Alberta shows areas of risk for midge damage in 2019. It is important to note that over such a wide range, populations in individual fields can be and often are highly variable. Producers should plan to monitor their fields when the midge adults are flying and their wheat is in the susceptible stage. In all areas of the province growers are urged to monitor their wheat fields from wheat head emergence to anthesis for the presence of midge adults. Regular field scouting on multiple nights in succession is important in understanding the population in a particular field..

Although a number of factors influence the overwintering survival of the midge, the survey and map provide a general picture of existing densities and the potential for infestation in 2017. Weather conditions, specifically temperature and moisture will ultimately determine the extent and timing of midge emergence during the growing season. Temperature and wind also play critical roles in egg laying activities of the female wheat midge. The level of damage from wheat midge is determined by the synchrony of wheat midge emergence and wheat and the number of wheat midge present. Look for the results of our wheat midge pheromone trapping in June and July to help track the emergence of adult midge.

Macroglens penetrans

Parasitism of midge larvae by a small wasp species (Macroglens penetrans) has been important in keeping wheat midge populations below the economic threshold in many areas. These beneficial wasps tend to thrive in warm, dry conditions. Parasite populations increase and decrease with changes in the midge population and are very important in moderating population levels in Alberta. It is important to understand that once midge has established in an area it unlikely to ever completely disappear. Low lying and moist areas in a field provide a refuge, enabling the population to survive even when conditions are not favorable in the rest of the field. These low population levels, however, also help sustain a population of natural enemies.

Management tools for dealing with midge

Diagnostic guide	Economic thresholds
Life cycle information	Frequently Asked Questions
Midge tolerant wheat varieities	Insect Pest Monitoring Network - Wheat midge monitoring
Scouting for wheat midge video

Wheat midge cocoon compared to canola seed

Wheat midge larva

Wheat midge larvae on wheat kernel

Who helped
The wheat midge survey was conducted by Alberta Agriculture and Forestry with assistance from:

Battle River Research Group	Chinook Applied Research Association
Farming Smarter	Lakeland Applied Research Association
Mackenzie Applied Research Association	Northern Peace Applied Research Association
Smoky Applied Research and Demonstration Association	County of Two Hills
Parkland County	MD Wainwright
Mountain View County