By Lucy Wyndham

Farmers in northern Dakota are now facing a new threat to their canola crops: a pest called the canola flower midge, also known scientifically as the Contarinia Brassicola. Canola flower midges have been found in the canola crops in the northern area of Dakota; they lay their larvae onto the canola plants, which can potentially drastically reduce the yield of the crop. This can greatly affect farmers’ livelihoods, particularly if they rely mostly on the canola plant for their income.

How was the pest found, and where did it come from?

Canola flower midges were found in Northern Dakota by deploying survey traps during the year 2020, and they show no sign of leaving. A total of 10 traps were used across seven counties, and six out of 10 trap sites found positive matches for the pest in five counties. 10 pheromone lures from the hotspots in Canada were also used to monitor the midge situation in Northern Dakota, according to professor and entomologist Janet Knodel from the North Dakota University Extension.

No area of America is pest-free. Indeed, simply in the home and garden, it’s possible to find up to 23 varieties of spider, most of which are harmless. However, some pests present more of a problem, and the canola flower midges are proving to be just that. They have, however, been found to be more concentrated in some areas than other. Six of the 10 pheromone lures found cases of canola flower midges, and these sites were in Pembina County, Towner County, Bottineau County, Cavalier County, and Walsh County in Northern Dakota. Of all the counties listed, Cavalier county was found to have the highest number of midges. The pest’s presence in Northern Dakota is new, as they have only previously been found in significant numbers in Saskatchewan and Alberta, Canada.

How do canola flower midges destroy the crop?

According to professor Knodel, canola flower midges deal their damage through the larvae. The larvae damage the developing flower, which causes significant swelling; this stops the flowers from growing. As a consequence, the flower stays closed and doesn’t produce any seeds or pods, which drastically reduces the yield of the affected crop.

Professor Knodel has offered some suggestions as to how affected farmers can tackle this canola pest in Northern Dakota. Knodel states that the infestations are usually worse at the edges of fields, and that planting dates also factor in. It appears that canola planted early in mid-May has more damaged pods and seeds compared to canola planted later in early June. Therefore, adjusting planting times can help to minimize damage to canola crops due to canola flower midge damage.

What else can be done to prevent canola flower midge damage?

Professor Knodel also recommends more extensive trapping and more field scouting to help keep on top of the infestations, as detecting the problem early and monitoring the population has been proven to be very effective in managing canola flower midge problems. This advice is key for all farmers in North Dakota involved in the canola industry, as they will be able to monitor high populations of the pest and hopefully prevent further damage to their crops.

Canola flower midges present a significant threat to canola crops in the Northern Dakota area, and farmers should be vigilant and take the threat seriously. However, there are measures that can be undertaken to prevent the damage, so if the advice is followed, serious damage to canola crops can be avoided.