Everyone who has ever taken a bite of Grandma’s saskatoon pie can appreciate the taste of those sweet purple berries.
But this year, some voracious feeders have also developed an appreciation for the taste of saskatoon leaves.
Greg Pohl, a forestry expert with the Canadian Forestry Service in Edmonton, says forestry experts are watching a tiny caterpillar that chews at the leaf and leaves only the veins, a process known as skeletonizing.
The caterpillars chew an oval-shaped chunk out of the leaf, cover themselves with the oval and begin skeletonizing the rest of the leaf.
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Forestry experts have only recently become aware of the problem and they suspect the caterpillar is an immature version of a moth in the incurvariidae family.
“So far, the problem appears to be restricted to wild saskatoon trees and appears to be very localized in the Lac la Biche, (Alta.,) area,” Pohl said.
“It has been seen in cultivated saskatoon berry crops as well but we don’t know how serious of a problem it might be for growers.”
The damage becomes apparent in mid-July and by mid-August, most of the caterpillars have finished feeding and have dropped to the ground to begin pupating.
“Superficially, affected leaves look brown but upon closer inspection, the leaves clearly have pieces cut out of them,” Pohl said.
“The caterpillars … turn into small dark pupae, which change into moths the following spring to repeat the cycle.”
Commercial saskatoon growers in northeastern Alberta said they had not heard of the new caterpillar and were not aware of new insect problems affecting berry trees.
Anyone who has seen this pest on saskatoon berry trees is asked to contact Pohl at 780-435-7211.
