Researchers with Agriculture and Agri-Food Canada and the University of Guelph say they’ve found a new midge species causing damage to canola in northeastern Saskatchewan and east-central Alberta.
This new species is similar to the swede midge, and belongs to the same Contarinia genus, but has yet to be named and scientifically described, according to a notice posted by SaskCanola on Monday:
For years there have been accounts of differences between swede midge populations in Saskatchewan and Ontario, including adult size, the number of generations per year, and the type and amount of damage reported. These hints, combined with extremely low capture rates of adult swede midge in pheromone-baited traps in Saskatchewan despite apparently high rates of adult swede midge emergence caught the attention of Dr. Boyd Mori, a trained chemical ecologist and new biologist at the SRDC.
Dr. Mori collected adult midges from soil emergence cages and reared larvae found in infested flowers. The resulting adult midges were sent to preeminent North American swede midge researchers at the University of Guelph, Dr. Rebecca Hallett and James Heal who immediately noticed differences between the midge from Saskatchewan and swede midges from Ontario: midges from Saskatchewan were more robust, had hairier wings and had slight differences in the antennae and genitalia compared to the swede midge.
These differences were confirmed by midge expert Dr. Bradley Sinclair with the Canadian Food Inspection Agency in Ottawa who also found several other physical differences. Using morphological differences, and DNA sequencing, the researchers concluded that the Saskatchewan midges were a separate species from the swede midge.
They say the only confirmed symptom of damage by this midge pest is “bottle”-shaped galled flowers. These damaged flowers do not produce pods or seeds.
More to come.
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