New midge with an appetite for canola not serious yet

Insect specialist says the unnamed species that attacks the flowers has only been confirmed in central Alberta

MEDICINE HAT, Alta. — Alberta canola had a smidge of new midge this season.

The new species of midge was first identified in 2016 and is still so new that it doesn’t have an official name. Although it has a liking for canola flowers, it doesn’t seem to be doing much damage.

Alberta Agriculture insect specialist Scott Meers said the new midge species was found mostly in central Alberta this year and none have been spotted south of Highway 12, which runs from Stettler to Altario.

“It’s a good news, bad news story I guess. The bad news, we have a new insect. The good news is that it’s not that serious. At least not yet,” said Meers.

The midge lays eggs in the flower, which hatch into maggots. The result is an orangey-looking, bottle-shaped flower. The flower never produces a pod, but the petals will cling to the plant and are not easily shaken off, as they would be if the flower had merely dried out.

“It only attacks the flowers and if you haven’t heard this before, I’ll be shocked, but flowers are somewhat expendable in canola. You can lose some flowers. You don’t lose a lot of yield. So we’re not that concerned at this point, unless it starts taking out all our flowers.”

Meers said a four-day survey in central Alberta this summer uncovered very low numbers of damaged flowers from the new midge.

He said there have been rumours for several years about Swede midge in Saskatchewan canola, but now he and other insect surveillance people think this recently identified midge is the species now seen in that province.

Meers noted the species might have been around for a while, despite remaining undiscovered by entomologists. He bases that on the existence of parasitoids that attack the midge. Those don’t usually arrive or develop unless they have sufficient prey.

Agriculture Canada scientists say the midge belongs to the Contarinia genus and looks similar to Swede midge, Contarinia nasturtii, but its species has yet to be determined.

Boyd Mori, a chemical ecologist at the Saskatchewan Research and Development Centre, first confirmed that the midges in that province were a new species. Midge expert Bradley Sinclair of the Canadian Food Inspection Agency also confirmed the findings based on various physical differences and DNA sequencing.

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